Latest posts

ENERGY TRANSFORMATION

Energy Transformation In Nature
The transformations of energy in an ecosystem start first with the contribution of energy from the sun. Energy from the sun is captured through the process of photosynthesis. Carbon dioxide is reacted with hydrogen obtained from the splitting of water molecules to manufacture carbohydrates (CHO).

Energy is stored in the high energy bonds of adenosine triphosphate, or ATP.

Because plant is the first stage in the production of energy for living things, it is known as primary production. Herbivores acquire their energy by consuming plants or plant products, carnivores obtain their by eating herbivores, and detritivores eat the droppings and carcasses of us all.

A trophic level is made up of organisms that make a living in a similar manner i.e. they are all primary producers (plants), primary consumers (herbivores) or secondary consumers (carnivores).

Dead tissue and waste products are manufactured at all levels. Scavengers, detritivores, and decomposers together account for the use of all such "waste. They consume the carcasses and fallen leaves.

They may be other animals, like crows and beetles, but finally it is the microbes that conclude the job of decomposition. Not unexpectedly, the amount of primary production varies a great deal from place to place, as a result of differences in the amount of solar radiation and the accessibility of nutrients and water.

Energy transfer through the food chain is ineffective. This means that less energy is accessible at the herbivore level than at the primary producer level, less at the carnivore level than at the herbivore level, and so on. The outcome is a pyramid of energy, with significant implications for comprehending the quantity of life that can be supported.

Normally, when we think of food chains, we imagine green plants, herbivores, etc. These are known as grazer food chains, because living plants are directly being eaten. In varieties of situations, the main energy input is not green plants but dead organic matter.

These are known as debris food chains. Examples are the forest floor or a woodland stream in a forested area, a salt marsh, and for the most part observably, the ocean floor in very deep areas where all sunlight is put out 1000's of meters above.

In conclusion, even though we have been talking about food chains, in reality the organization of biological systems is much more complex than can be represented by a simple "chain". There are a lot of food links and chains in an ecosystem, and the collection of all these food chains is referred to as food web.

Food webs can be highly complex, where it looks like "the whole thing is linked with everything else", and it is vital to comprehend what are the main crucial linkages in any particular food web.

Energy Flow Through Ecosystems
Ecosystems sustain themselves by cycling energy and nutrients gained from external sources. At the first trophic level, primary producers -plants, algae, and some bacteria make use of solar energy to manufacture organic plant material through photosynthesis.

Herbivores—animals that feed mainly on plants constitute the second trophic level. Predators that eat herbivores make up the third trophic level; if larger predators are available, they constitute still higher trophic levels.

Organisms that feed at many trophic levels for instance grizzly bears that consume berries and salmon are classified at the uppermost of the trophic levels at which they feed. Decomposers, which constitute bacteria, fungi, molds, worms, and insects, break down wastes and dead organisms and return nutrients to the soil.

Typically, about 10 percent of net energy production at one trophic level is transferred to the next level. Processes that lessen the energy transferred between trophic levels consist of respiration, growth and reproduction, defecation, and non-predatory death (organisms that die but are not eaten by consumers).

The nutritional quality of material that is eaten as well determines how competently energy is transferred, because consumers can change high-quality food sources into fresh living tissue more proficiently than low-quality food sources.

The low rate of energy transfer between the different trophic levels makes decomposers usually more significant than producers in terms of energy flow. Decomposers process large amounts of organic material and return nutrients to the ecosystem in inorganic forms, which are then utilized again by primary producers.

Energy is not recycled during decomposition, but relatively released, mainly as heat. This is why compost piles and fresh garden mulch is warm). The diagram below illustrates the flow of energy (dark arrows) and flow of nutrients (light arrows) through ecosystems.

biology
Energy and nutrient transfer through ecosystems
An ecosystem's gross primary productivity (GPP) is the total sum of organic matter that it produces through the process of photosynthesis. Net primary productivity (NPP) means the total sum of energy that remains available for plant growth after subtracting the fraction that plants use for respiration.

Productivity in land ecosystems by and large increases with temperature up to about 30°C, after which it declines, and is optimistically correlated with moisture. On land primary productivity consequently is topmost in warm, wet zones in the tropics where tropical forest biomes are situated.

In contrast, desert scrub ecosystems have the lowest productivity because their climates are excessively hot and dry.

In the oceans, light and nutrients are significant controlling factors for productivity. In the Oceans light penetrate only into the topmost level of the oceans; therefore photosynthesis takes place in surface and near-surface waters.

Marine primary productivity is topmost near coastlines and other areas where upwelling brings nutrients to the surface, encouraging plankton blooms. Overflow from land is as well a source of nutrients in estuaries and along the continental shelves.

Among aquatic ecosystems, algal beds and coral reefs have the uppermost net primary production, while the lowest rates take place in the open as a result of nutrients lack in the illuminated surface layers.

The number of trophic levels an ecosystem support depends on a lot of factors, which includes the amount of energy entering the ecosystem, energy loss between trophic levels, and the form, structure, and physiology of organisms at every level.

At higher trophic levels, predators are usually physically larger and are able to make use of a fraction of the energy that was manufactured at the level beneath them; therefore they have to forage over more and more large areas to meet up their caloric needs.

Due to these energy losses, the majority of terrestrial ecosystems have a maximum of five trophic levels, and marine ecosystems commonly have a maximum of seven. This dissimilarity between terrestrial and marine ecosystems is probably as a result of the fundamental characteristics of land and marine primary organisms.

In marine ecosystems, microscopic phytoplanktons carry out the majority of the photosynthesis that that takes place whereas plants do the majority of photosynthetic job on land.

Phytoplankton are minute organisms with exceptionally uncomplicated structures, therefore the majority of their primary production is eaten up and utilized for energy by grazing organisms that eat them.

On the contrary, a huge fraction of the biomass produced by land plants like roots, trunks, and branches, cannot be made use of by herbivores for food, therefore proportionately less of the energy preset through primary production moves up the food chain.

Growth rates may as well be a factor. Phytoplankton are exceptionally small but grow very rapidly, therefore they support large populations of herbivores even though there may be smaller amount of algae than herbivores at any given instance.

On the contrary, land plants may take years to grow to maturity, therefore a typical carbon atom stays a longer seat time at the primary producer level on land than it does in a marine ecosystem.

Additionally, locomotion costs are regularly higher for terrestrial organisms than those in aquatic environments.

The simplest way to explain the flux of energy through ecosystems is as a food chain in which energy travels from one trophic level to the other, without leading to more complex relationships between each species.

A few extremely simple ecosystems may be made up of a food chain with just small number of trophic levels. For instance, the ecosystem of the remote wind-swept Taylor Valley in Antarctica is made up of just bacteria and algae that are eaten by nematode worms.

What is most frequently seen is a situation where producers and consumers are linked in intricate food webs with a few consumers feeding at a lot of trophic levels.

A crucial result of the loss of energy between trophic levels is that contaminants gather in animal tissues through a process referred to as bioaccumulation.

As contaminants bioaccumulate up the food web, organisms at top trophic levels can be endangered even if the pollutant is just available to the environment in extremely minute quantities.

Decomposition (or Rotting)
This is the process through which organic materials are broken down into simpler forms of matter. The process is vital for recycling the finite matter that possesses physical space in the biome. Bodies of living organisms start to putrefy shortly after death.

Even though no two organisms decompose in the similar way, they all go through the same chronological stages of decomposition. The science which studies decomposition is in general known as taphonomy.

Difference between abiotic from biotic decomposition (biodegradation)
Aboitic decomposition means degradation of a substance or material through chemical or physical means like the changes that occur during hydrolysis.

The biotic decomposition means the metabolic breakdown of materials or substances into simpler components by living organisms generally through the actions of microorganism. Animal decomposition starts at the moment of death, as a result of two factors:

1. Autolysis-This is the breaking down of tissues by the body's own interior chemicals and enzymes, and

2. Putrefaction- This is the breakdown of tissues by bacteria. These processes discharge gases that are the principal source of the unmistakably putrid odor of decaying animal tissue.

The main decomposers are bacteria or fungi, although larger scavengers as well play a significant role in decomposition if the body is available to insects, mites and other animals.

The main significant arthropods that are mixed up in the process consist of carrion beetles, mites, the flesh-flies (Sarcophagidae) and blow-flies (Calliphoridae), like the green-bottle fly seen in the summer.

The major crucial non-insect animals that are naturally involved in the process comprise mammal and bird scavengers, like coyotes, dogs, wolves, foxes, rats, crows and vultures.

A few of these scavengers as well eliminate and scatter bones, which they swallow at a later time. Aquatic and marine environments have break-down agents that comprise bacteria, fish, crustaceans, worms and a massive amount of carrion scavengers.

Decomposers form a significant part of our ecosystem. They are in fact minute micro-organisms that assist in the maintenance of the ecological balance in our environment. When any living organism dies ,the blood circulation ceases and the body turns static, decomposers begin to alter the matter from complex to simpler substances.

The decomposers work on dead matter and transform them into simpler form leaving behind the manure which makes the soil fertile and makes available suitable conditions for the plants to grow. Owing to this, the ecological cycle continues moving from something like

Plants - Herbivores - Carnivores - Die and Decomposed by Decomposers - Soil - Plants. Decomposers can readily decompose biodegradable substances but can as well decompose non-biodegradable substances. It's just metals, and the like that take thousands of years to get decomposed.

The amount of energy available at each trophic level lessens as it moves through an ecosystem. As small as 10 percent of the energy at every trophic level is transferred to the subsequent level; the remaining is lost mainly through metabolic processes like heat.

FOOD WEB AND TROPHIC LEVEL

Food Webs And Trophic Levels
Energy, water, nitrogen and soil minerals are additional important abiotic components of an ecosystem. The energy that flows through ecosystems is acquired mainly from the sun. It normally enters the system through photosynthesis, a process that as well captures carbon from the atmosphere.

By feeding on plants and on one another, animals play a significant role in the movement of matter and energy through the system.

They as well influence the quantity of plant and microbial biomass present. By breaking down dead organic matter, decomposers liberate carbon back to the environment and make easy nutrient cycling by changing nutrients stored in dead biomass back to a form that can be easily used by plants and other microbes.

Ecosystems are restricted both by external and internal factors. External factors like climate, the parent material which forms the soil and topography, determine the entire structure of an ecosystem and the manner things work within it, but are not themselves influenced by the ecosystem.

Other external factors are time and latent biota. Ecosystems are energetic entities—regularly, they are disturbed periodically and are in the course of recovering from a few disturbances in the past.

Ecosystems in related environments that are situated in different parts of the world can possess a few dissimilar characteristics merely because they are made up of various species.

The introduction can lead to significant shifts in ecosystem function. Internal factors not only regulate the processes of ecosystem but are as well restricted by them and are frequently subject to feedback loops.

While the resource inputs are normally regulated by external processes such as the climate and parent material, the accessibility of these resources inside the ecosystem is regulated by interior factors like decomposition, root competition or shading.

Additional internal factors are disturbance, succession and the types of species within the ecosystem. Even though humans exist and function within ecosystems, their collective effects are huge enough to control external factors such as climate.

Biodiversity influences ecosystem function, just like the processes of disturbance and succession.

Ecosystems make available a lot of of goods and services upon which people rely; the principles of ecosystem administration recommend that instead of managing individual species, natural ought to be managed at the level of the ecosystem itself.

Classifying ecosystems into ecologically standardized units is a crucial step towards efficient ecosystem management, but there is no particular, agreed-upon technique to carry this out.

The living organisms that constitute an ecosystem can be separated into three main groups:

Organisms are divided into autotrophs, heterotrophs and decomposers according to their energy pathways. Autotrophs are those organisms that are capable of manufacturing energy-containing organic molecules from inorganic raw material with the help of fundamental energy sources like sunlight.

Plants are the major example of autotrophs, using photosynthesis.

All other organisms ought to make use of food that comes from other organisms in the form of fats, carbohydrates and proteins. These organisms that feed on others are called heterotrophs.

1. Autotrophs are organisms that can manufacture their own food from the substances present in their surroundings with the help of light (photosynthesis) or chemical energy (chemosynthesis). Producers are green plants that make use of sunlight to manufacture food from nutrients obtained from the soil.

2. Heterotrophs are incapable of synthesizing their own food. They depend on other organisms -- both plants and animals – for their nutritional requirements. Strictly, the definition implies that autotrophs acquire carbon from inorganic sources such as carbon dioxide (CO2) while heterotrophs obtain their reduced carbon from other organisms.

Autotrophs are normally plants; they are as well known as "self feeders" or "primary producers". Consumers/heterotrophs cannot produce their own food and ought to obtain it by eating other animals and plants. All animals are consumers.

They are further classified into herbivores, carnivores and omnivores. Herbivores, or plant-eaters, are primary consumers. They are as well source of food for carnivores. Omnivores eat both plant and animal materials.

3. Decomposers: They are mainly bacteria and fungi, which break down the complex substances of dead plants and animals into uncomplicated substances, which are then made accessible once again by producers.

Comparison between Autotroph and Heterotroph
Differences Autotroph Heterotroph
Manufacture own food Yes No
Level in the Food chain Primary Secondary and tertiary
Types Photoautotroph, Chemoautotroph Photoheterotroph, Chemoheterotroph
Examples Plants, algae and some bacteria Herbivores, omnivores and carnivores
Definition An organism that is capable of forming nutritional organic substances through simple inorganic materials like carbon dioxide. Heterotrophs cannot manufacture organic compounds from inorganic sources and as a result rely on consuming other organisms in the food chain.
What they eat or How they eat? Manufacture their own food for energy. They eat plants and animals to get energy.
Energy Production in the eco system:
A) Autotrophs manufacture their own energy through one of the following two methods:

1) Photosynthesis - Photoautotrophs make use of energy from sun to convert water from the soil and carbon dioxide from the air into glucose. Glucose makes available energy to plants and is utilized in the production of cellulose which is made use of in the manufacturing of cell walls.

Examples of photoautotrophs are Plants, algae, phytoplankton and some bacteria.

Carnivorous plants like pitcher plant make use of photosynthesis for energy production but rely on other organisms for other nutrients like nitrogen, potassium and phosphorous. Therefore, these plants are in essence autotrophs.

2. Chemosynthesis - Chemoautotrophs make use of energy from chemical reactions to manufacture food. The chemical reactions are normally between hydrogen sulfide/methane with oxygen.

Carbon dioxide is the chief source of carbon for Chemoautotrophs. Example of chemoautotrophs is bacteria found inside active volcano, hydrothermal vents in sea floor and hot water springs.

B) Heterotrophs live by feeding on organic matter manufactured by or accessible in other organisms. There are two types of heterotrophs:

1. Photoheterotroph – These are the type of heterotrophs that make use light for energy but which cannot make use of carbon dioxide as their carbon source. They obtain their carbon from compounds like carbohydrates, fatty acids and alcohol. Examples are purple non-sulfur bacteria, green-non sulfur bacteria and heliobacteria.

2 Chemoheterotroph – These are Heterotrophs that obtain their energy through oxidation of preformed organic compounds, i.e. by eating other organisms either dead or alive. Examples are animals, fungi, bacteria and more or less every pathogen.

Type of organism Energy source Carbon source
Photoautotroph Light Carbon dioxide
Chemoautotroph Chemicals Carbon dioxide
Photoheterotroph Light Carbon from other organisms
Chemoheterotroph Other organisms Other organisms
The Energy Cycle
All of the energy of life is made available from oxidation, the burning of sugars, as a countless multiplicities of chemical changes occur before they eventually end up once more as water and carbon dioxide. Plants make use of their own sugars for living and growing, but the huge surpluses they manufacture support the rest of the organic world.

Animals are consumers. They either survive by eating directly from green plants, or indirectly by eating other animals that survive by eating green plants. Animals offer recyclable chemicals back to plants through the process of excretion of their body wastes or when their organic remains decompose back into the soil.

Decomposers break down dead plants and animals and allow their components to be returned to the environment and be reutilized.

Therefore, these non-living parts of the ecosystem are cycled from the surroundings to living organisms and back to the surroundings.

At every step in the food chain, much of the potential energy is given out as heat. This type of energy loss limits the number of steps in the food chain to four or five. Energy, which emanates from the sun and is essential for life, cannot be recycled and is lost as it flows one way through the system.

Processes of Ecosystems
This figure with the plants, zebra, lion, etc shows the two main ideas about the way ecosystems operate: ecosystems possess energy flows and ecosystems cycle materials. These two processes are connected but they are not really the same.

Energy flows and material cycles.
Energy is captured into the biological system in form of light energy, or photons and is transformed into chemical energy in organic molecules by cellular processes which include photosynthesis and respiration, and are finally converted into heat energy.

This energy is dissipated, which means that it is lost to the system as heat; once it is lost it cannot be recycled. Without the constant input of solar energy, biological systems would soon become extinct.

This is why the earth is an open system with respect to energy.

Elements like carbon, nitrogen, or phosphorus enter living organisms in a variety of ways. Plants obtain elements from the surrounding atmosphere, water, or soils.

These nutrients are eaten by animals and during decomposition these materials are not destroyed or lost, but are returned to the environment so the earth is a closed system with regard to elements apart from a meteorite entering the system now and then.

The elements are cycled continually between their biotic and abiotic states within ecosystems. Those elements whose supply is likely to limit biological activity are known as nutrients.

Interaction that exists in an Eco-system
Biotic components and abiotic components of an ecosystem interact with one another and have influence on one another. If the temperature of an area decreases, the life existing there must adapt to it.

Global warming, or the global increase in temperature as a result of the greenhouse effect, will speed up the metabolism rates of the majority of organisms.

Metabolic rate increases with temperature due to the fact that the nutrient molecules in the body are more likely to have contact with as well as react with one another when energized by heat. To adapt to these circumstances, cold-blooded organisms could reside in the shade and not vigorously look for food during daylight hours when the sun is at its brightest.

The carbon and energy integrated into plant tissues (net primary production) is either eaten by animals while the plant is alive, or it remains uneaten when the plant tissue dies and turns into debris. In terrestrial ecosystems, nearly 90% of the NPP are eventually broken down by decomposers.

The remaining is either eaten by animals while still alive and enters the plant-based trophic system, or it is eaten after it has died, and enters the debris-based trophic system. In aquatic systems, the proportion of plant biomass that is being eaten by herbivores is a much higher.

In trophic systems photosynthetic organisms are the primary producers. The organisms that consume their tissues are known as primary consumers or secondary producers—herbivores. Organisms which feed on microbes (bacteria and fungi) are termed microbivores.

Animals that feed on primary consumers are known as secondary consumers- carnivores. Every one of these is referred to as a trophic level.

The sequences of consumption that start from plants to herbivores, to carnivore make up what is known as food chain. In real life situation, the systems are much more complicated than this. In such cases organisms will usually feed on more than one type of food, and may feed at more than one trophic level.

Carnivores may eat a few preys which are part of a plant-based trophic system and others that are part of a debris-based trophic system. A bird for example can feed on both herbivorous grasshoppers and earthworms, which eat debris.

These real life systems, with all the complications make up what is known as food webs instead of food chains.

ECOLOGICAL FACTORS

The abiotic factors are known to play a major role in the environment. The lists of abiotic factors are:

• clouds,

• weather,

• latitude,

• temperature,

• oxygen,

• salinity,

• soil (edaphic factors),

• air,

• water,

• sunlight,

• humidity,

• topography,

• pH,

• Atmospheric gases.

These lists of the abiotic factors affect the ecosystem differently as well interact with the biotic factors in an environment.

The Soil or Edaphic Factors
The edaphic factors are the abiotic factors that affect the. These factors are subdivided into:

• Soil texture - The texture of the soil varies and depends on particles like clay to larger particles like sand. Sandy soils are suitable for growing plants and are well aerated and are easy to cultivate. Sandy soils cannot keep hold of much water and has few nutrients required for plant growth.

• Soil air - Soil air is the spaces between the soil particles where it is not filled with soil water. The soil air in a particular soil sample determines its firmness.

• Temperature of soil – The temperature of the soil is a crucial factor, temperature of soil less than 30cm is said to be constant although there are seasonal variations. The decaying caused by decay-causing microorganisms is small at lower temperature.

• Soil water - Soil water can be divided into three types - capillary water, hygroscopic water and gravitational water.

• Soil pH – The pH of the soil affects the biological activity of the soil and a few mineral's availability. The pH of soil affects the growth and development of plants.

• The organisms and the decaying material in the soil are referred to as soil solution and this increases the fertility of the soil.

biology
Light
Light is the primary source of energy to more or less all type of ecosystems. The light energy is made use of by the autotrophs to manufacture food by the process of photosynthesis with a combination of other inorganic substances.

The factors of light like its quality, intensity and the length or duration of light play a crucial role in an ecosystem.

• The quality of light affects the aquatic ecosystems environment, the blue and red light is mostly absorbed here and this does not penetrate deep into the water. Some algae have particular pigments that enable them to as well absorb the other colors of light.

• The intensity of light or light intensity depends on the latitude and the season of the year. During the period from March to September, the Southern Hemisphere receives below 12 hours of sunlight whereas it receives more than 12 hours of sunlight during the remaining part of the year.

• A number of plants flower merely during a specific time of the year.

One of the factors is as a result of the length of dark period. Depending on the intensity of light the plants are classified as short-day plants (Example Chrysanthemum sp., Datura stramonium etc.) Long-day plants (Examples - Spinach, barley, wheat, radish, clover, etc.) Day-neutral plants (Examples - Tomato, maize, etc.)

Temperature
Temperature affects the distribution of plants and animals. The occurrence of frost is crucial to determining the distribution of plants as the majority of the plants cannot alter the freezing of their tissues. Below are some examples of the effects of temperature in plants and animals:

• The blooming of flowers either in the day or night is as a result of the temperature difference between day and night.

• Some biennial plants sprout during spring or summer and this is referred to as vernalization.

• Some fruit trees need cold temperature in order to blossom or produce flower in the spring time.

• Animals have a clear distinction between being cold blooded or warm blooded.

• Seasonal migration is observed in a few animals.

Water
Habitats of animals and plants differ greatly. It could range from aquatic environments to the dry deserts. Water is an essential requirement for life and every biotic components of the ecosystem are directly dependent on water for their growth and survival.

Based on the water requirements of plants, they are classified as:

• Hydrophytes (Example - Water lilies)

• Mesophytes (Example - Sweet pea, roses)

• Xerophytes (Example - Cacti, succulent plants)

Land animals are prone to desiccation and these animals demonstrate different types of adaptations in order to prevent this from occurring. Some of the adaptations noticeable in terrestrial animals are:

• Body covering which reduces loss of water.

• A few animals possess sweat glands which are employed as cooling devices.

• The tissues of a few animals such as camel are tolerant to water loss.

• Some insects are known to absorb water from the water vapor directly from the atmosphere.

Wind
Air currents also known as winds are a result of interaction that exists between expansion of hot air and convection in the mid latitudes. This composite interaction affects the earth's rotation and leads to a centrifugal force which lifts the air at the equator. Some of the consequences of wind are:

• Winds as well carry water vapor; which may undergo condensation and precipitate in the form of rainfall, hail or snow.

• It also assists in the dispersal of pollen grains of a few plants as well as in the dispersal of insects.

• Wind erosion as well leads to dispersal of topsoil.

Atmospheric Gases
Atmospheric gases are gases like oxygen, nitrogen and carbon dioxide:

• All organisms need oxygen for respiration.

• Carbon dioxide is utilized by green plants to manufacture food by the process of photosynthesis.

• Nitrogen is essential for all plants and atmospheric nitrogen is fixed by nitrogen fixing bacteria through the action of lightening.

Topography
Topography or shape of the land is the landscape shapes and is determined by the aspects of slopes and elevations. Topography gives diversity to the ecosystems. For instance: The grassland topography is made up of various forms like hills, prairies, cliffs, low lying areas and so on which offers variability to living organisms.

• The aspect of the direction of the land facing also varies as the land facing towards the south or the sun ar hotter and drier than areas in the north, which are away from the sun.

• Slope of on areas is as well crucial due to the fact that water may run downhill and may soak in ground which makes it accessible for plants. The areas in the southern part with slopes will be much hotter and drier than the northern areas with slopes.

Climate
Climate of a region involves the average rainfall, temperature and the patterns of winds that take place in that region. Climate is one of the most crucial abiotic factors of an ecosystem.

• Temperature of an area and the precipitation factor regulates the type of vegetation in the area like whether the region is grassland or a forest.

• The rainfall in an area affects the productivity of the area and the types of plants that would grow and thrive there. For instance: The climate in a grassland ecosystem is dry and hot during the spring and summer and is cool and cold during the winter.

• Precipitation in winter is snow instead of rainfall. During summers, more water is evaporated from the grasslands making the region deficient of moisture.

Abiotic Factors - Affecting an Organism
The properties of temperature, pressure, humidity rainfall, sunshine cloud and wind in a given place and time is what is termed as the weather condition of that place. The average weather conditions of an area, which as well incorporates the atmospheric conditions, season and so on is what made up what is known as the climate.

Climatic Factors - Temperature
Temperature is one of the crucial and alterable environmental factors. It penetrates into all region of the biosphere and deeply influences every forms of life by increasing or decreasing a few of the vital activities of the organism. It is commonly a limiting factor for the growth or distribution of animals and plants.

Climatic Factors - Humidity
Humidity is the amount of water vapour available in the atmosphere. It can be measured by a Hygrometer. Humidity is to a great extent affected by intensity of solar radiation, temperature, altitude, wind exposure, cover and water condition of the soil.

Climatic Factors - Wind
The wind is the air in motion. Wind velocity can be measured with an Anemometer. It is an essential ecological factor of the atmosphere that affects greatly the plant life on flat plains, along sea coasts and at high altitudes in mountains.

Climatic Factors - Rainfall and Water
Rainfall is a source for ground water and relative humidity. The amount of rainfall greatly affects the vegetation as well as animal population of a particular region.

Climatic Factors - Atmospheric Gases
The gases present in the atmosphere are mainly oxygen, carbon dioxide and nitrogen which to a great extent influence the life of living organisms.

Edaphic Factors
The word soil is derived from the Latin word solum meaning earthy material in which plants grow. The science which deals with the study of soil is known as Soil Science, Pedology (pedos = earth) or edaphology (edaphos = soil).

Ecological Adaptations
The phenotype is the physical expression of the organism. The phenotype exhibits variations as a result of variations in the environmental conditions in a habitat.

Aerial Habitat
A few organisms have become secondarily adapted for aerial existence. Organisms that are able to do their activities in the aerial environment are known as aerial or arboreal organisms.

Aquatic Habitat
Water form the habitat of a huge variety of organisms. These organisms are known as aquatic organisms. The aquatic habitat be fresh water or marine environment.

Terrestrial Habitat
Land makes available a wide variety of habitat for the organisms. Organisms whose life depends on land are called as terrestrial organisms.

Hydrophytic Habitat
This is a habitat with excessive water supply. The plants growing in this kind of environment do not face the problems of water loss as a result of transpiration, wilting and drought. They are referred to as hydrophytes.

Ecological Adaptations - Mesophytes
These are land plants which grow in moist habitats and need well aerated soils. They prefer soil and air with moderate humidity. They keep away from soils that are waterlogged and soils that contain great quantity of salts.

Ecological Adaptations - Xerophytes
These are plants adapted to grow in dry habitats. They are divided into three categories on the basis of their morphology and life - cycle pattern.

Ecological Adaptations - Halophytes
The plants, which grow and thrive in salty habitats, are referred to as Halophytes. There is lofty concentration of salts like sodium chloride, MgSO4 and so on in these habitats. As the habitat is physiologically dry as a result of the salt contents, the halophytes exhibits characteristics similar to those of Xerophytes.

Adaptation to Environment In Animals
Animals as well have to face the problem of water scarcity or abundance. They also have to meet a variety of vagaries of nature. Therefor, for their survival under these conditions, animals have as well developed a number of adaptations to meet the challenges.

Adaptation to Environment In Animals
Adaptations for flight are known as volant adaptations. Bats, birds and insects are well adapted for an energetic flight.

ECOLOGY OF POPULATION

Ecology of Population
Population ecology is a field of ecology that deals with the dynamics of species populations and how these populations act together with the environment. In population ecology, density-dependent processes take place when population growth rates are synchronized by the density of a population.

Even though population ecology is a branch of biology, it makes available fascinating problems for mathematicians and statisticians who work in population dynamics.

The term population biology is frequently employed interchangeably with population ecology, even though 'population biology' is more commonly used when learning about diseases, viruses, and microbes, and 'population ecology' is made use of more regularly when studying plants and animals.

Population ecology is the branch of ecology that deals with the factors that influence the population size of a particular organism, population growth rate, and spatial dispersion of individuals with populations. Demography is the division of population ecology that deals with statistics associated to human populations.

Factors affecting population size
The factors that affect the population size are:

• The birth rates

• The death rates,

• Emigration, and

• Emigration.

Birth rates and immigration increase the number of individuals in a population while death rates and emigration reduce the number of individuals from a population. When additional individuals are being added to a population than the number that is being removed, it results to a population increase.

On the other hand, when the number of individuals that are being reduced from a population is more than the number that is being added to the population, it leads to a decrease in population size.

Population sizes would normally remain the same when the rate of individuals that are removed from it is equal to the rate of individuals that are added to it.

Such a population is said to be in a state of dynamic equilibrium.

Factors that affect population growth rates
Population growth rates are affected by relations between the abiotic and biotic environment. Climactic factors like precipitation and temperature can have great direct and indirect effects on population sizes.

Temporal rises and falls in abiotic conditions can be crucial causes of disparity in population sizes. Biotic factors like competition and predation can directly and indirectly influence population sizes.

Population dynamics can be affected by interactions with members of their own species (like intraspecific competition) and members of dissimilar species (like interspecific competition, predation, and mutualism).

Models of population growth
These are mathematical models developed by population ecologists to study the growth of populations. The simplest model of population growth is the exponential growth model which presupposes that the per capita growth rate -the change in population size/time/individual is constant.

Due to populations growing exponentially keep on growing at an increasing rate; the exponential growth model is not a practical model for the majority of populations.

The logistic growth model is a more practical model due to the fact that it permits the per capita growth rate to change with population size.

The carrying capacity, the population size at which the population growth rate equals zero, is attained when the per capita birth rate (# births/time/individual) is equal to the per capita death rate (# deaths/time/individual).

In logistic growth, birth and death rates are dependent on density; as population size increases, the per capita birth rate reduces (as a result of increased competition for resources) and the per capita death rate increases as a result of enlarged competition for resources, the increased multiplication of disease or an increase in predation that arises when predators are attracted to areas of lofty population sizes.

In the real world, patterns of population growth may be more complex than predicted by uncomplicated models due the fact that majority of populations are synchronized by a selection of density reliant (like competition and dispersal of disease) and density independent factors (like climate and disturbances).

Spatial dispersion
Individuals in a population may multiply across the environment in different patterns like clumped dispersion, smooth dispersion, or random dispersion. Interaction with both the abiotic and biotic environments can affect and determine the patterns of spatial dispersion.

For instance, clumped dispersions may occur when individuals are restricted to living in erratic with the suitable abiotic environmental conditions and smooth dispersions may arise as the result of intraspecific competition.

Human population growth
The study of human population growth is a particularly crucial subset of the field of population ecology.

Humans have had a distinctive pattern of population growth. Human demographers are concerned with the factors that cause patterns to differ between various countries and predicting what will occur to human population growth in the future

Ecological succession
Ecological succession is the pragmatic processes of change in the structure of species in an ecological community over time. Within any community a few species may become less abundant over some period of time, or they may even disappear from the ecosystem entirely.

In the same vein, over some time interval, some species within the community may become more plentiful, or fresh species may even occupy the community from nearby ecosystems.

This visible change over time in what is living in a specific ecosystem is "ecological succession". There are two types of ecological succession- The primary succession and secondary succession.

Primary and secondary successions both produce a constantly altering mixture of species inside communities as disruptions of various intensities, sizes, and frequencies change the landscape. The chronological progression of species during succession, nevertheless, is not random.

At every stage particular species have developed life histories to utilize the particular conditions of the community. This situation compels a moderately expected sequence of alteration in the species composition of communities during succession.

At first only a small number of species from surrounding habitats are able to thrive in a disturbed habitat. As fresh plant species emerge, they change the habitat by altering things like the amount of shade on the ground or the mineral constitution of the soil.

These changes permit other species that are more suited to this modified habitat to replace the old species. These recent species are outmoded, in turn, yet by newer species.

A related succession of animal species occurs, and interactions between plants, animals, and environment affect the pattern and rate of succession change.

In a few environments, succession reaches a climax, which gives rise to a stable community subjugated by a small number of prominent species. This state of equilibrium known as the climax community, is thought to happen when the web of biotic interactions turn very complex that no other species can be allowed.

In a few environments, constant small-scale disruptions create communities that are a varied mixture of species, and any species may thrive.

Primary ecological succession is one of two types of biological and ecological succession of plant life, that occurs in an environment in which fresh substrate devoid of vegetation and normally lacking soil, like a lava flow or area left from drew back glacier, is deposited.

Primary succession can as well be defined as ecological succession that takes place in an opening of unoccupied, infertile habitat or that exists on an environment that is free of vegetation and normally lacking topsoil.

An example of primary succession is the original advancement of plant or animal communities in an area where no soil exists at the outset like a lava flow that results from volcanic eruption or rigorous landslide that enveloped the land.

The primary succession is essential in pioneering the area to create conditions that are favorable for the growth of other types of plants and animals.

Secondary succession takes place in areas where a community that beforehand existed has been removed; it is typified by smaller-scale disturbances that do not get rid of all life and nutrients from the environment.

Secondary succession is one among the two types of ecological succession of plant life. Secondary succession is the series of community alterations that occur on a formerly occupied, but distressed or smashed habitat.

Examples are areas which have been cleared of obtainable vegetation like after tree-felling in woodland and destructive events like fires.

Secondary succession is normally much swifter than primary succession for the following reasons:
• There is previously an existing seed bank of appropriate plants in the soil.

• Root systems uninterrupted in the soil, stumps and other plant parts from formerly existing plants can quickly rejuvenate and grow.

• The fertility and structure of the soil has also previously been adapted to a large extent by preceding organisms to make it more fit for growth and colonization.

Why ecological succession take place
Every living species has a group of environmental conditions under which it will thrive and reproduce most optimally.

In a particular ecosystem, and under that ecosystem's range of environmental conditions, those species that can grow for the most part competently and produce the most viable children will become the majorly rich organisms.

Ecological succession may as well happen when the conditions of an environment unexpectedly and considerably alter. A forest fires, wind storms, and human activities such as agriculture all significantly change the conditions of an environment.

These considerable forces may as well wipe out species and consequently modify the dynamics of the ecological community triggering a mix up for dominance among the species still present.

Ecological succession on the Natural track
Succession is one of the main natural themes. It is possible to detect both the current process of succession and the effects of past succession events at roughly any point along the track.

The fluctuations of various species within our numerous communities exemplify both of the types of motive forces of succession: the collision of a well-known species to change a site's ecological conditions, and the collision of large exterior forces to abruptly change the environmental nature of a site.

Some particular examples of visible succession are:
1. The growth of hardwood trees which includes ash, poplar and oak within the red pine planting area. The result of this hardwood tree growth is the increased shading and resultant mortality of the sun loving red pines by the shade tolerant hardwood seedlings.

The shaded forest floor situation created by the pines limits the growth of sun-loving pine seedlings and permits the growth of the hardwoods. The result of the growth of the hardwoods is the reduction and senescence of the pine forest.

2. The raspberry thickets growing in the sunny forest parts of the canopy produced by wind-thrown trees. Raspberry plants need sunlight to grow and thrive. Under the thick shade canopy principally of the red pines but as well under the dense stands of oaks, there is no adequate sunlight for the raspberry's survival.

Nevertheless, in any place where there has been a tree fall, the raspberry canes have multiplied into impenetrable thickets.

How humans are are affected by ecological succession
Ecological succession is a power of nature. Ecosystems, due to the internal species changes and outdoor forces already mentioned, there are constant process of transformation and re-structuring.

To be pleased about how ecological succession affects humans and as well to begin to understand the inconceivable time and monetary cost of ecological succession, you only have to see a newly tilled garden plot.

Clearing the land for the garden and preparing the soil for planting showcases the main exterior event that radically re-structures and disrupts a previously existing ecosystem.

Scope of literature

Literature is a form of human expression. But not everything expressed in words - even when organized and written down - is counted as literature. Those writings that are primarily informative, technical, scholarly, journalistic—would be excluded from the rank of literature by most, though not all, critics. Certain forms of writing, however, are universally regarded as belonging to literature as an art. Individual attempts within these forms are said to succeed if they possess something called artistic merit and to fail if they do not. The nature of artistic merit is less easy to define than to recognize. The writer need not even pursue it to attain it. On the contrary, a scientific exposition might be of great literary value and a pedestrian poem of none at all.

The purest (or, at least, the most intense) literary form is the lyric poem, and after it comes elegiac, epic, dramatic, narrative, and expository verse. Most theories of literary criticism base themselves on an analysis of poetry, because the aesthetic problems of literature are there presented in their simplest and purest form. Poetry that fails as literature is not called poetry at all but verse. Many novels—certainly all the world's great novels—are literature, but there are thousands that are not so considered. Most great dramas are considered literature (although the Chinese, possessors of one of the world's greatest dramatic traditions, consider their plays, with few exceptions, to possess no literary merit whatsoever).

The Greeks thought of history as one of the seven arts, inspired by a goddess, the muse Clio. All of the world's classic surveys of history can stand as noble examples of the art of literature, but most historical works and studies today are not written primarily with literary excellence in mind, though they may possess it, as it were, by accident.

The essay was once written deliberately as a piece of literature: its subject matter was of comparatively minor importance. Today most essays are written as expository, informative journalism, although there are still essayists in the great tradition who think of themselves as artists. Now, as in the past, some of the greatest essayists are critics of literature, drama, and the arts.

Some personal documents (autobiographies, diaries, memoirs, and letters) rank among the world's greatest literature. Some examples of this biographical literature were written with posterity in mind, others with no thought of their being read by anyone but the writer. Some are in a highly polished literary style; others, couched in a privately evolved language, win their standing as literature because of their cogency, insight, depth, and scope.

Many works of philosophy are classed as literature. The Dialogues of Plato (4th century bc) are written with great narrative skill and in the finest prose; the Meditations of the 2nd-century Roman emperor Marcus Aurelius are a collection of apparently random thoughts, and the Greek in which they are written is eccentric. Yet both are classed as literature, while the speculations of other philosophers, ancient and modern, are not. Certain scientific works endure as literature long after their scientific content has become outdated. This is particularly true of books of natural history, where the element of personal observation is of special importance. An excellent example is Gilbert White's Natural History and Antiquities of Selbourne (1789).

Oratory, the art of persuasion, was long considered a great literary art. The oratory of the American Indian, for instance, is famous, while in Classical Greece, Polymnia was the muse sacred to poetry and oratory. Rome's great orator Cicero was to have a decisive influence on the development of English prose style. Abraham Lincoln's Gettysburg Address is known to every American schoolchild. Today, however, oratory is more usually thought of as a craft than as an art. Most critics would not admit advertising copywriting, purely commercial fiction, or cinema and television scripts as accepted forms of literary expression, although others would hotly dispute their exclusion. The test in individual cases would seem to be one of enduring satisfaction and, of course, truth. Indeed, it becomes more and more difficult to categorize literature, for in modern civilization words are everywhere. Man is subject to a continuous flood of communication. Most of it is fugitive, but here and there—in high-level journalism, in television, in the cinema, in commercial fiction, in westerns and detective stories, and in plain, expository prose—some writing, almost by accident, achieves an aesthetic satisfaction, a depth and relevance that entitle it to stand with other examples of the art of literature.

ECOLOGICAL MANAGEMENT

Ecological Management
Association - In community ecology and phytosociology an association is a type of ecological community with a conventional species symphony, dependable physiognomy (structural appearance) which exists in a particular type of habitat.

The term association was originally invent ed by Alexander von Humbold and was made formal by the International Botanical Congress in 1910.

An association can be defined as a real, incorporated body formed either by species interactions or by related habitat requirements or it can be defined as simply an ordinary spot along a scale.

There are a lot of examples in nature of two organisms living in close association with each other. The relationship can be made up of two animals, two plants, a plant and an animal, or merely a fungus and an algae for example as obtained in lichens.

Biologists have made efforts to explain different types of biological associations like 'symbiosis' and 'mutualism' and 'parasitism' but it is frequently difficult to identify where one type of association stops and another starts.

It is in all probability better to take these associations as part of a wide range of scale that begins with free-living organisms that rely on others for food, to two organisms that will fail to exist if they are not constantly together like the alga and fungus that join to form each lichen 'species'.

Types of biological association
1. Symbiosis:
This is derived from a Greek word which simply means 'living together' and can be utilized to explain any association that exist between two organisms.

2. Mutualism:
This can be used to describe an association between two organisms and where both organisms seemingly benefit from each other.

3. Commensalism:
This is a type of association where one organism known as the commensal benefits, and the other known as the host is seemingly unaffected. In ecology, commensalism is a type of relationship between two organisms where one organism benefits but the other is neutral.

There is no harm or benefit to the neutral organism. Commensalism is derived from the English word commensal, meaning "sharing of food" in human social interaction, which was in turn derived from the Latin cum mensa, meaning "sharing a table"

Examples of Commensal Relationships
Commensalism is much more difficult to exhibit than parasitism and mutualism, for it is simpler to show a single example where the host is affected, than it is to demonstrate or invalidate that possibility.

Cattle Egrets and Livestock
An example of commensalism is cattle egrets pasturing in fields together with cattle or other livestock. As cattle, horses, and other livestock graze on the field, their movements stir up different types of insects which are being fed on by the cattle egrets.

The egrets benefit from this relationship due to the fact that the livestock have assisted them to discover their foods while the livestock are characteristically not affected by it.

Tigers and Golden Jackals
In India, one golden jackals barred from their pack have been found to be forming commensal relationships with tigers.

4. Parasitism
This is the type of association where one organism known as the the parasite benefits, while the other known as the host is negatively affected, injured, weakened, sickened or killed. An example of parasitism is the association between the parasitic tapeworms and the vertebrate hosts.

This type of association would as well suit the relationship that exists between a carnivore and its live prey and herbivore and the plant it feeds on, particularly if they are extremely specialized in the food they eat.

Parasites are usually defined as organisms that cannot survive without their host and which have unique modifications to their body or their life cycle for this association. In a lot ways though, the variation that exists between a lion eating a gazelle and a flea feeding on a dog, is an issue of relative size.

A lot of sea slugs have evolved close relationships with other organisms. Solar Powered Sea Slugs is another rather different group of relationships that have been discovered with sea slugs. This relationship involves plants and plant organelles.

A group, the herbivorous sacoglossan sea slugs keep chloroplasts and other plant plastids alive from the plants they consume and make use of the sugars they synthesize from photosynthesis for their own nutrition.

Conventionally, parasite is used to describe organisms that are visible to the naked eye, or macroparasites like the protozoa andhelminths. Parasite currently includes microparasites, which are generally smaller, like viruses and bacteria.

A few examples of parasites include the plants mistletoe and cuscuta, and animals like the hookworms.

As opposed to predators, parasites do not kill their host. They are usually much smaller than their host, and will frequently live in or on their host for an extensive period. Both the parasite and the predator are particular instances of consumer-resource interactions.

Parasites exhibit a high degree of specialization, and replicate at a faster rate than their hosts.

Parasites diminish host biological fitness by common or dedicated pathology, like parasitic castration and mutilation of secondary sex characteristics, to the modification of host behavior.

Parasites increase their fitness by exploiting hosts for resources necessary for their survival, e.g. food, water, heat, habitat, and transmission. Although parasitism applies unmistakably to a lot of cases, it is part of a range of types of interactions that exist between species, instead of the exclusive category.

In a lot of cases, it is not easy to illustrate that the host is harmed. In others, there may be no obvious specialization on the part of the parasite, or the interaction that exists between the organisms may be momentary.

Types of parasitic relationship between organisms
Parasites are classified based on their interactions with their hosts and on their life cycles. An obligate parasite is completely reliant on the host to complete its life cycle, while a facultative parasite is not.

Human head lice (Pediculus humanus capitis) are ectoparasites. Parasites that live on the surface of the host are known as ectoparasites . Example-mites. The parasites that live inside the host are known as endo-parasites which as well include parasitic worms.

Endoparasites can survive in one of two forms: intercellular parasites ie parasites that inhabit spaces in the host's body or intracellular parasites ie parasites that inhabit cells in the host's body.

Intracellular parasites, like protozoa, bacteria or viruses, have a propensity of depending on a third organism, which is commonly referred to as the carrier or vector. The vector does the function of transmitting them to the host.

An instance of this interaction is the spread of malaria, caused by a protozoan of the genus Plasmodium, to humans by the bite of an anopheline mosquito. Those parasites living in an intermediary position, being half-ectoparasites and half-endoparasites, are every now and then called mesoparasite.

An epiparasite is a parasite that feeds on another parasite. This relationship is as well occasionally known as hyperparasitism. An example is exhibited by a protozoan (the hyperparasite) inhabiting the digestive tract of a flea living on a dog.

Social parasites take advantage of interactions that exists among members of social organisms like ants or termites. An instance is Phengaris arion, a butterfly whose larvae make use of mimicry to parasitize definite species of ants.

In kleptoparasitism, parasites share food obtained by the host. An instance is the brood parasitism practiced by cuckoos and cowbirds, which do not construct nests of their own and leave their eggs in nests of other species.

The host acts as a "babysitter" as they raise the young as their own. If the host takes away the cuckoo's eggs, a few cuckoos will come again and attack the nest to force host birds to remain subject to this parasitic association.

Pollution of the environment
Pollution can be defined as introduction of contaminants into the atmosphere. There are different types of pollution. These pollutions are as a result of a lot of varieties of sources. They all have many effects to the surroundings.

Different Types of Pollution
Air Pollution
Air pollution can be defined as any contamination of the atmosphere that interrupts the natural composition and chemistry of the air we breathe.

It can be in the form of particulate matter like dust or excessive gases such as carbon dioxide or other vapors that cannot be efficiently removed through natural cycles, like the carbon cycle or the nitrogen cycle.

Air pollution care caused by a lot of sources. Some of the major sources of air pollution are:

• automobile or exhaust from manufacturing industries

• Forest fires, volcanic eruptions, dry soil erosion, and other natural sources

• Building construction or demolition

Depending on the amount of air pollutants in the atmosphere, a lot of effects can be observed like smog increases, increased acidic rain, reduction of crop yield as a result of insufficient oxygen, and higher rates of asthma. A lot of scientists think that air pollution also leads to global warming.

Water pollution:This is introduction of contaminants into water surfaces, which can be in form of chemical, particulate, or bacterial matter that reduces the quality and purity of the water. Water pollution can take place in the oceans, rivers, lakes, and underground reservoirs, and as various sources of water.

Causes of water pollution are:
• Higher sediment from soil erosion

• Poor waste disposal and littering

• Leaching of soil pollution into water sources

• Decay of organic material into water sources.

The effects of water pollution are reduction in the quantity of drinkable water accessible, reduction of water supplies for crop irrigation, and impacting fish and wildlife populations that need water of a particular purity for survival.

Soil Pollution
Soil, or land pollution, is contamination of the soil that inhibits natural growth and balance in the land whether it is utilized for cultivation, habitation, or a wildlife preserve. A few soil pollution, like the creation of landfills, is purposeful, while some are accidental and can have broad effects.

Sources of Soil pollution are:
• Harmful waste and sewage spills

• Non-sustainable farming practices, like excessive use of inorganic pesticides

• Strip mining, deforestation, and other negative practices

• Domestic dumping and littering

Soil contamination can result to impaired growth and low crop yields, loss of wildlife, water and visual pollution, soil erosion, as well as desertification.

Noise Pollution
Noise pollution is undesirable levels of noises brought about by human activity that disturb the average of living in the affected area. Sources of noise pollution are:

• Roadtraffics

• Airports

• Railroads

• Manufacturing plants

• Construction or demolition

• Concerts

Some noise pollution may be short term while other sources are long term. Some of the effects of noise pollution are impaired hearing, wildlife disturbances, and a generalized degradation of lifestyle.

Radioactive Pollution
Radioactive pollution is uncommon but awfully damaging, and even deadly, when it happens. Due to its intensity and the difficulty of averting the harm it may cause, there are stringent government regulations to control radioactive pollution.

Sources of radioactive pollution are:
• accidents or leakage of nuclear power plant

• Poor disposal of nuclear waste

• Uranium mining operations

Radiation pollution can lead to birth defects, cancer, sterilization, and other health issues for human and wildlife populations. It can as well sterilize the soil and lead to water and air pollution.

WHAT IS LITERATURE?

Literature: A Body of written works. The name has traditionally been applied to those imaginative works of "poetry" and "prose" distinguished by the intentions of their authors and the perceived aesthetic excellence of their execution. Literature may be classified according to a variety of systems, including language, national origin, historical period, genre, and subject matter.

Definitions of the word literature tend to be circular. The 11th edition of Merriam-Webster's Collegiate Dictionary considers literature to be "writings having excellence of form or expression and expressing ideas of permanent or universal interest." The 19th-century critic Walter Pater referred to "the matter of imaginative or artistic literature" as a "transcript, not of mere fact, but of fact in its infinitely varied forms." But such definitions assume that the reader already knows what literature is. And indeed its central meaning, at least, is clear enough. Deriving from the Latin littera, "a letter of the alphabet," literature is first and foremost humankind's entire body of writing; after that it is the body of writing belonging to a given language or people; then it is individual pieces of writing.

But already it is necessary to qualify these statements. To use the word writing when describing literature is itself misleading, for one may speak of "oral literature" or "the literature of preliterate peoples." The art of literature is not reducible to the words on the page; they are there solely because of the craft of writing. As an art, literature might be described as the organization of words to give pleasure. Yet through words literature elevates and transforms experience beyond "mere" pleasure. Literature also functions more broadly in society as a means of both criticizing and affirming cultural values.

ECOSYSTEM

Ecological Factors in Aquatic and Terrestrial Ecosystem
The aquatic environment ought to always be taken as a lawful consumer of water, whose requirements ought to be fulfilled alongside the fundamental human requirements, and at the forefront of any other demand.

In the case of water projects requiring impoundment, this means the maintenance of flow in the reaches of the river downstream of the impounding structure, dam, or diversion. Environmental flows are essential to:

• keep up the riverine ecology

• revitalize the riverine aquifers

• keep up the river channel

Factors Affecting Aquatic Ecosystems
Inconsistency and change are natural processes in aquatic ecosystems, and ecosystem communities and individual organisms have on several occasions adapted to diverse environmental conditions. The factors affecting the aquatic environment can be as a result of natural causes or as a result of human factors.

Human activities that affects the aquatic ecosystem can be due to pollution, changes or alteration to the landscape or hydrological systems, and their overall long lasting larger-scale effects like the global climate change.

The complexity of aquatic ecosystems and the connections within them can make it difficult to predict the effect or what may be the result of such disturbances on them.

These interconnections among them entail that any damage or harm done to a single component of the ecosystem can result to impacts on other components of the ecosystem.

Augmenting or amplifying our understanding of aquatic ecosystems can result to enhanced practices that reduce the effect these would have on aquatic environments.

It can therefore be concluded that influences on the aquatic ecosystem can be as a result of:

• Natural or physical factors

• Human factors and their practices

Example of such factors that affects the aquatic ecosystem is the eutrophication.

Another factor that could affect the aquatic ecosystem significantly and which possess a serious threat to the survival of organim in aquatic environment everywhere in the world is the invasion of species Water Hyacinth (Eichhornia crassipes) and Water Fern (Azolla filiculoides).

These two aquatic plants, native to South America, have invaded varoius sections of the Vaal River and many other rivers of the world. Whereas Water Fern is limited to the upper catchments of the Vaal River, Water Hyacinth is seen in the upper-middle Vaal and extends as far as Douglas Weir.

Biological control agents, which includes the weevil, Stenopelmus rufinasus, has been comparatively useful and successful in the control of the invasion; nevertheless, they go on spreading, with Water Hyacinth currently discovered occasionally in the lower reaches of the main-stem of Orange-Senqu River.

In South Africa for example, a few introduced species include two species of trout (Salmo trutta and Oncorhynchus mykiss).

These species were originally introduced for sport fishing in South Africa but have currently had effects on the populations of local minnow species in Lesotho and South African parts of the Orange-Senqu River basin, and are seen all through the basin, although in smaller numbers, from the Maluti Mountains downstream to the Gariep and Vanderkloof dams.

Other factors that have effects on the aquatic ecosystems are listed in the table below.

Factors affecting aquatic ecosystems
Factor Impact
Foreign species Opening up foreign species out-compete indigenous species for space, nutrients and sunlight availability.
Dams, inter-basin transfers, hydro-electrical flow releases, irrigation and mining activities Customized flow regime or hydrology
Pollution from mines and return water flows from irrigation Reduction in water quality, including nutrient build-up on the surface of the water and salanisation
Reduced flood management and made to order seasonal flows Geomorphologic modification of the river channel as a result of lower flows which results in less or no scoured
Riparian and in-stream vegetation is laid out of action and continues to get worse Floating aquatic plants rise in number with reduced flow. Alterations to the shape of the wetted perimeter of the river channel, with lower water levels leading to the dryness of river banks, temporary exposure of open to attack banks and water bank collapse Enhanced advantage to pioneer reeds, like the Common Reed (Phragmites australis), under reduced flow, with improved distribution and patch size, and in so doing gathering up sediments, blocking channels and leading to large disturbances when washed out during the time of large floods. These frequently lead to the formation of reed mats that cause blockages downstream and make worse the effect of floods. Loss of local trees and gallery forest in the riparian belt as a result of reduced floods (moisture), reduced seed dispersal, more recurrent or everyday hot fires due to the increase in the reed beds and a reduced amount of cooling effect as the formerly moist riverbanks are now drier Agricultural encroachment into the riparian belt would be greater than before due to less than before flooding activities and waterlogged soils Invasion by foreign vegetation, particularly Mesquite (Prosopis spp.), got worse due to a loss of home-grown vegetation and disturbance for example through fires and agricultural activities Alterations in the compositions of species and abundance as a result of fertilizers and salts draining into the river, for example Common Reed (P.australis) and Wild Tamarisk (Tamarix usneoides) increasing and posing a negative effect on safsaf willow, Kaapse wilger or Cape Willow (Salix mucronata).
The Factors Affecting Terrestrial Ecosystem

It is not uncomplicated to compare terrestrial and aquatic systems due to the fact that there are a very big variety of these environments.

It is possible to be aware of the terrestrial part of the biosphere, a small number of units with characteristic vegetation and climate, each of which is made up of a complex of communities to a large extent. These units are referred to as biomes and six major biomes are by and large recognized, namely the:

1. Tundra,
2. Taiga ( coniferous forests ),
3. Deciduous Forests,
4. Grasslands,
5. Tropical Rain Forests,
6. Deserts.
Similarities between Terrestrial and Aquatic eco systems
• In both terrestrial and aquatic environments the ecosystems include communities made up of a diversity of species,

• within both terrestrial and aquatic communities there are populations at the different trophic levels of the ecosystem,

• There is a great deal of reciprocal interdependence that exists between species in both the eco systems of the terrestrial and aquatic environments,

• In terrestrial and aquatic ecosystems that are without interruption, equilibrium is attained, i.e. exceptionally few major changes are noticed over a period of time,

• In both aquatic and terrestrial ecosystems stratification also known as vertical zonation takes place.

Differences between Terrestrial and Aquatic systems
• The fact that aquatic ecosystem environments are very rich in nutrients makes it possible for them to support more live than the corresponding terrestrial ecosystems environment.

The minute wandering photosynthetic organisms of the oceans, known collectively as phytoplankton are taken to be the main photosynthesizers, or primary producers, of the earth,

• In aquatic ecosystem environments their tendency to remain stable are much more stable than the corresponding terrestrial environments, due to the fact that it is only affected by smaller fluctuations in temperature and other variables than terrestrial environment,

• aquatic organisms are hardly ever open to the elements of desiccation whereas the terrestrial organisms are over and over again exposed to desiccation and are normally comparatively resistant to drying out,

• oxygen due to their less availability is every now and then a limiting factor an aquatic habitats but this is hardly ever the case in terrestrial habitats,

• light can be a limiting factor in a few aquatic habitats and ecosystems, but in the majority of terrestrial eco system environments, there is hardly ever a limiting factor of light,

• Terrestrial animals are influenced to a greater extent by gravity, whereas in the aquatic ecosystem, the greater influence on their life is made by the availability and quality of water.

The kinds and numbers of species in a typical environment whether it is terrestrial environment or aquatic, environment are typically determined by physical environmental factors. In areas where there are alterations to the physical factors, there will be a transition zone that exit between two communities known as an ecotone.

In an ecotone, plant species from the communities will be discovered and a diversity of wildlife species.

The terrestrial community on an archetypal farm in Tennessee for example includes the cottontail rabbit, hayfields, northern bobwhite quail and grain.

Other species present include the woodlot, which is composed of foxes, trees, deer and songbirds. Other members of the community include the meadow mouse, stream bank willow, dogwood, opossum, skunk and sparrow hawk.

A few more other species are fence-row trees and shrubs, groundhogs, blacksnakes and weasels.

The cottontail rabbit, groundhog and meadow mouse eat from the same clover field and are seen to be present in the same fencerow and end up as food for a fox or hawk.

The skunk looks for refuge in a groundhog burrow, searches fields and pass through lanes to get grubs and mice, and rarely finds and feasts on birds' eggs. In due course, an owl, nesting in an old dead hurdle in the woodlot, may possibly prey upon the skunk.

A hawk hovers over the hayfield and jumps over for insects as well as mice to feed itself and its young ones

Every plant and animal members of a community live and function in their own place and fill up their niche. This is how complicated a community can be.

The Interrelatedness of Life
Interrelatedness is a main concept in ecology. For instance, a plant may put up with different extremes of temperature based on the amount of moisture on hand. And, the way the environmental factors are interrelated, is also the manner in which biological factors are related.

Man is situated at the top of a lot of food chains, and is dependent on phytoplankton or grasses at the bottom of those chains for his survival.

Apart from the clear food chain relationships, relationships between predator-prey or host-parasite communities is made up of a lot of numerous interrelationships of which we are not fully conscious of. Man is presently starting to be aware of these.

Ecological Succession
Communities do not remain the same but alter over a period of time. This is majorly due to a process known as ecological succession. We see this process all around us as abandoned farmland alters to weed fields, brush land and subsequently to a forest.

One community succeeds another in various stages as conditions change that is favorable to another suite of wildlife species.

The first stage in succession is known as the pioneer stage, which is made up of bare habitat conditions, like an exposed rock. This stage stays until conditions alter to the extent that soil gathers up and plants are capable of thriving there.

These changes go on and on till formation of a climax community, which is in equilibrium with soil and climatic conditions. Species of a climax community do not generate conditions unfavorable to themselves or additionally favorable to other species.

COMPONENT OF THE ECOSYSTEM

Ecosystem- Components of the ecosystem and sizes
Ecology is the study of the associations and interactions of the organisms and the environment in general. The living place or dwelling place of any organism is known as habitat. Inside every habitat there are variations or micro habitats.

Inside every given habitat, we would notice physical or abiotic environment as well as living organisms or biotic factors. There is interaction and interdependence between organisms in a given habitat.

The word ecology is derived from two Greek words: oikos which means 'house' or place of abode and logos which means to discuss or study. Literally, ecology means the study of organism 'at home' in their natural environment.

Ecosystems means living organism that exist together in a symbiotic relationship with their environment. Living organisms in an ecosystem fight with one another over who would turn into the most successful at reproducing and surviving in a particular niche, or environment.

There are two major components of the ecosystem: abiotic components and biotic components.

The abiotic components of any ecosystem are the physical properties of the environment; the biotic components are the living organisms that live a particular ecosystem.

Biotic Components of the Ecosystem:
The biotic components of an ecosystem are the living organisms that live in an ecosystem. These living organisms in an ecosystem assist in the transfer and cycle of energy inside any given eco system.

They are classified based on the source of energy requirement of their body. Producers like plants manufacture their own energy without consuming other living organisms; plants obtain their energy through the process of photosynthesis with the energy for the reaction obtained from sunlight.

Consumers can be seen on the subsequent level of the food chain.

There are three major types of consumers: herbivores, carnivores and omnivores. Herbivores feed on plants; carnivores get their food by eating other living organisms whether carnivores or herbivores, and omnivores are animals that possess the ability to digest both plant and animal tissue.

Therefore, the biotic components of the ecosystem which is composed of the plants, animals and microbes work together and are reliant on the abitoic factors.

Abiotic Components of the Ecosystem:
Abiotic components are and ecological factor that acts of living components during any part of their life. Abiotic factors are the factors that are either physical or chemical factors that are the characteristic of the environment under study.

A lot of ecological studies have been conducted on the significance or importance of the main abiotic factors which control the physical and biological components in an ecosystem at different ranges of time and space.

Abiotic factors are the non-living components of a habitat. The abiotic factors in an ecosystem are grouped into soil (edaphic), air, topography, meteorology, availability of water and quality of water.

The meteorological factors are temperature, wind, sun, humidity and precipitation. The activities and growth of plants and animals are a result of many of these abiotic factors.

Abiotic facotrs are the non-living components of the ecosystem. The chemical, geological factors like soil, minerals, rocks and physical factors like temperature, wind, water, sunlight are defined as abiotic factors.

The abiotic factors affect the ecosystem and play a very important role in the biology of the ecosystem. The abiotic facts factors as well include average humidity, topography and natural disturbances, light, acidity, radiation, and every organic and inorganic components of the ecosystem.

The quantity of the abiotic components available in the ecosystem is referred to as 'the standing stage'.

Abiotic components of an ecosystem therefore are made up of the nonorganic aspects of the environment that decides the living things that can survive in that particular ecosystem.

Temperature of an ecosystem differs by latitude; locations close to the equator are hotter than locations that are closed to the poles or the temperate zones. Humidity regulates and determines the amount of water and moisture in the air and soil, which, in turn, influence rainfall.

Topography is the layout of the land in relation to its elevation. For instance, according to the University of Wisconsin, land situated in the rain shadow of a mountain will experience less precipitation of rainfall.

Natural disturbances include things like tsunamis, lightning storms, hurricanes and wild fires.

An ecosystem is a community of living organisms (plants, animals and microbes) in addition to the nonliving components of their environment like air, water and mineral soil, interacting as a system. These biotic and abiotic components are known to be linked together through nutrient cycles and energy flows.

Since ecosystems are defined by the complex of interactions among living organisms, and between the organisms and their surrounding environment, they can be of whichever size but normally comprises specific, restricted spaces even though a few scientists are of the opinion that the whole world is an ecosystem.

An ecosystem is made up of the biological community that takes place in some locality, and the physical as well as chemical factors that make up its non-living or abiotic environment. There are a lot of examples of ecosystems like a pond, a forest, an estuary or grassland.

The boundaries are not limited in an objective manner, though a few times they appear obvious, just like the shoreline of an undersized pond. Normally, the boundaries of an ecosystem are selected for practical reasons which have to do with the objectives of that specific study.

The study of ecosystems mostly consists of the study of a few processes that connect the living, or biotic components to the non-living, or abiotic, components. Energy transformations and biogeochemical cycling are the major processes that comprise the field of ecosystem ecology.

As discussed earlier, ecology is generally defined as the interactions of living organisms with one another and with the environment where they live. Ecology can be studied at the level of the individual, the population, the community, and the ecosystem.

Studies of ecology on the basis of individuals are mainly in terms of physiology, reproduction, development or behavior, and studies of ecology on the basis of populations are normally focused on the habitat and resource requirements of individual species, their group behaviors, population growth, and factors that limit their abundance or leads to their extinction.

Studies of ecology on the basis of communities investigates the way populations of a lot of species interact with one another, like predators and their prey, or competitors that contribute to common needs or resources.

In ecosystem ecology all of this is put together and try to comprehend the way the entire system operates. This means that, instead of worrying majorly about specific species, a focus is rather directed towards the main functional aspects of the system.

These functional aspects include things like the amount of energy that is generated through the process of photosynthesis, how energy or materials flow along the various steps of a food chain, or things that controls the rate of decomposition of materials or the rate at which nutrients are recycled in the system.

A table showing the Components of an Ecosystem
ABIOTIC COMPONENTS BIOTIC COMPONENTS
Sunlight Primary producers
Temperature Herbivores
Precipitation Carnivores
Water or moisture Omnivores
Soil or water chemistry (e.g., P, NH4+) Detritivores
By and large, this set of environmental factors is very essential roughly everywhere, in all ecosystems.

Habitually, biological communities are made up of the "functional groupings" illustrated on the table above.

A functional group is a biological class composed of organisms that carry out majorly the same type of function in the system; for example, all of the photosynthetic plants or primary producers constitute a functional group.

Belonging to a functional group does not rely immensely on who the real players (species) are rather on what function they carry out in the ecosystem.

Organism and Environment
Each and every one of living organisms possesses its particular surrounding medium of environment with which it constantly interacts and remains totally adapted.

Habitat
The surroundings or the localities in which a lot of plants and animals naturally occur are referred to as habitats.

The word habitat means living or dwelling place. Habitat of an organism is a part of the total environment of the region and it ought to offer the residing organism food, shelter and climatic conditions that are appropriate for the survival of the organism as well as its reproduction and thriving.

Microhabitat
The term microhabitat refers to a small region or area within a particular habitat with particular features that go well with a few organisms better than others. The term microhabitat is as well used for a smaller and immediate habitat of an organism.

The Ecosystem is the basic unit of ecological study. It means a self-sustaining system in which living organisms and their non-living environment interact to exchange energy and materials.

All systems function to form the biosphere, that part of the earth which supports life, and is made up of the atmosphere, bodies of water and soil to a depth of lots of feet.

Ecologists normally study communities which are systems (like a pond, marsh, forest or selfcontained aquarium. Within the ecosystem, water and materials are constantly being recycled.

Energy, which comes from sunlight is very essential for life and is used by green plants to manufacture sugars via photosynthesis. The process of photosynthesis produces fuel that keeps the whole living world sustained.

Habitat and Niche
Habitat is the place where a living organism lives. For instance, the habitat of waternet (an algae) is a calm pond, while a robin's habitat may be a suburban garden. Habitat requirements are complicated not simple. The requirements are appropriate food, shelter, water and space.

Physical factors like light, heat and moisture ought not to go beyond the organism's limit of tolerance. Over the years, plants and animals have developed adaptations like periods of dormancy, hibernation, cyst formation and changes in body structure, which allow them to live through unfavorable times and circumstances.

Niche can be defined as the role of an organism in its habitat. This composed of every aspect of its structure, behavior and activities. For instance, the biological niche of an owl might be defined as a nocturnal, carnivorous, predatory bird.

Some organisms occupy a lot of various niches during their life histories. For instance, a mosquito in the larval stage of life lives in shallow water habitats as a primary consumer, but occupies a completely different habitat and niche as an adult.

The Community
The biotic community is the living part of an ecosystem, and can be defined as a group of plant and animal populations living together (interacting with one another) in a specific habitat. Organisms are connected in food chains, and all the food chains of a community constitute a food web.

Every organism in the community occupies a specific niche. The main multifaceted communities have the majorities of niches occupied and, consequently, are more dissimilar.

Complex communities normally are the main stable, due to the fact that they are least likely to be affected by change.

In some communities, one or many species may be dominant. Dominant species are normally plants. These plants are the majorly common, convert the most energy, regulate the climate for the other organisms, and frequently make available the main source of food and shelter.

Communities like an oak/hickory forest, are frequently named after the dominant species.

THEORIES OF EVOLUTION

Charles Darwin and Lamarck's Theories of Evolution
Darwin's Theory of Evolution is the extensively held concept that all life is interrelated and has descended from a common ancestor: the birds and the bananas, the fishes and the flowers are all related.

Darwin's general theory presumes the development of life from non-life and stresses an entirely naturalistic (undirected) "descent with modification". That is, composite creatures develop from more simple ancestors unsurprisingly over time.

In summary, as random genetic mutations take place in an organism's genetic code, the valuable mutations are conserved due to the fact that they help the organism to survive.

This process is referred to as natural selection. These advantageous mutations are transferred to the next generation. Over time, helpful mutations mount up and the result is a completely different organism (not just a variation of the original organism but completely different creature).

Charles Darwin is renowned for his theory of evolution, but he was not the only person to develop a theory of evolution. Charles Darwin was an English naturalist. He studied variation in plants and animals during a five-year cruise around the world in the 19th century.

He gives explanations about evolution in a book known as on the Origin of Species, which was publicized in 1859.

Darwin's theory raised controversy amongst his contemporaries and his ideas were only slowly accepted, Even though a few people still do not believe in them today. The reasons why people fail to believe in his theories are:

• Darwin's theory was the contrary of religious belief that God had made all the animals and plants on Earth

• Darwin did not have an adequate amount of evidence at the time to convince a lot of scientists

• It took 50 years after Darwin's theory was made public to discover the way inheritance and variation worked.

Darwin's Theory of Evolution –The theory of Natural Selection
Whereas Darwin's Theory of Evolution is a relatively young prototype, the evolutionary worldview itself is as old as ancient times.

Ancient Greek philosophers like Anaximander hypothesized the development of life from non-life and the evolutionary descent of man from animal.

Charles Darwin basically brought something fresh to the old philosophy - a credible mechanism known as "natural selection." Natural selection acts to safeguard and build up minor advantageous genetic mutations.

Assuming that a member of a species evolved a functional advantage, (it grew wings and learned to fly).

Its offspring would inherit that benefit and transfer it to their offspring. The inferior (deprived) members of the same species would slowly but surely die out, leaving only the superior (privileged) members of the species.

Natural selection is the conservation of a functional advantage that allows species to compete better in the undomesticated.

Natural selection is the natural equivalent to household breeding. Over the centuries, human breeders have created spectacular changes in domestic animal populations by choosing individuals to breed.

Breeders do away with unwanted traits steadily over time. Likewise, natural selection does away with inferior species progressively over time.

Darwin's Theory of Evolution - Slowly But Surely
Darwin's Theory of Evolution is a slow but gradual process. Darwin wrote, "...Natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps."

Therefore, Darwin accepted that, "If it could be established that any multifaceted organ existed, which could not probably have been fashioned by numerous, consecutive, slight modifications, my theory would completely break down.

Such a composite organ would be referred to as an "irreducibly multifaceted system".

An irreducibly composite system is one consisted of numerous parts, all of which are essential for the system to function.

If even one part is missing, the whole system will stop working or functioning. Every individual part is fundamental.

Therefore, such a system could not have evolved gradually, part by part. The familiar mousetrap is a day to day non-biological instance of irreducible complication.

It is made up of five fundamental parts: a catch (to hold the bait), a commanding spring, a thin rod known as "the hammer," a griping bar to lock the hammer in place, and a stage to mount the trap.

If any one of these parts is not there, the machinery will not work. Every individual part is integral. The mousetrap is irreducibly composite.

Darwin's Theory of Evolution - A Theory In Crisis
Darwin's Theory of Evolution is a theory in crisis in view of light of the tremendous advances we've made in molecular biology, biochemistry and genetics over the past fifty years.

We presently know that there are in fact tens of thousands of irreducibly composite systems on the cellular level.

Specific complication pervades the microscopic biological world.

Molecular biologist Michael Denton wrote, "even though the tiniest bacterial cells are extremely small, weighing less than 10-12 grams, each is in effect a genuine micro-miniaturized factory encompassing thousands of elegantly designed pieces of complicated molecular mechanism, made up in total of one hundred thousand million atoms, far more complex than any machine built by man and entirely without equivalent in the non-living world.

And we don't require a microscope to examine irreducible complication.

The eye, the ear and the heart are all examples of irreducible complexity, though they were not acknowledged as such in Darwin's day.

Nonetheless, Darwin admitted, "To assume that the eye with all its matchless contrivances for adjusting the focus to diverse distances, for admitting dissimilar amounts of light, and for the alteration of spherical and chromatic aberration, could have been produced by natural selection, appears quite illogical in the utmost degree

Lamarck's theory of evolution:
Jean-Baptiste Lamarck on the other hand was a French scientist who evolved an alternative theory of evolution at the start of the 19th century. His theory included two ideas:

1. A trait which is made use of more frequently by an organism grows bigger and stronger, and one that is not being utilized gradually and at the end becomes extinct.

2. Any feature of an organism that is enhanced through use is transferred to the s offspring of the organism.

Nevertheless, we now know that in majority of cases this type of inheritance cannot occur.

Lamarck's theory cannot take care of every observation made consigning life on Earth.

For example, his theory implies that every organism would slowly and surely turns composite and simple organisms become extinct.On the contrary, Darwin's theory can account for the continued presence of simple organisms.

Darwin was not the first naturalist to suggest that species altered over time into fresh species—that life, as we would say currently, evolves.

In the eighteenth century, Buffon and other naturalists started to initiate the idea that life may not have been constant or permanent since creation.

By the end of the 1700s, paleontologists had puffed up the fossil collections of Europe, offering a picture of the ancient times at odds with an unchanging natural world.

And in 1801, a French naturalist named Jean Baptiste Pierre Antoine de Monet, Chevalier de Lamarck took a great theoretical step and proposed a full-blown theory of evolution.

Lamarck started his scientific career as a botanist, but in 1793 he became one of the founding professors of the Musee National d'Histoire Naturelle as an expert on invertebrates.

His work on classification of worms, spiders, molluscs, and other boneless creatures was far above the findings of his time.

Change through use and disuse
Lamarck was hit by the similarities of a lot of the animals he examined and was highly impressed by the escalating fossil record.

It led him to dispute that life was not rigid or stable. When environments are altered, organisms had to alter their behavior to remain alive.

If they start to make use of an organ more than they did in the past, it would gradually increase in size during its lifetime.

If a giraffe stretched its neck for leaves, for instance, a "nervous fluid" would flow into its neck and cause it to grow longer.

Its offspring would inherit the longer neck, and extra and improved stretching would make it longer still over a lot of generations.

In the meantime organs that organisms stopped making use of would shrink.

Organisms moved to higher complexity
This type of evolution, for which Lamarck is majorly well known today, was only one of two mechanisms he projected. As organisms adapted to their surroundings, nature as well drove them inescapably upward from simple forms to progressively more composite ones.

Like Buffon, Lamarck is of the thought that life had started via spontaneous generation. But he maintained that fresh prehistoric living things sprang up throughout the history of life; today's microbes were merely "the fresh kids on the block."

Lamarck as well postulated that organisms were driven from simple to increasingly more complex forms.

The characteristic example used to illustrate the concept of use and disuse is the extended neck of the giraffe. According to Lamarck's theory, a given giraffe could, over a lifetime of twisting to reach high branches, grow an elongated neck.

A key fault of his theory was that he could not illustrate the way this could occur even though he discussed a "natural tendency toward perfection."

Another example Lamarck made use of was the toes of water birds.

He postulated that from years of straining their toes to swim through water, these birds grew elongated, webbed toes to enhance their swimming.

These two examples illustrate the way use could change a characteristic or a feature.

In the same way, Lamarck believed that disuse would result in a character or feature becoming reduced.

The wings of penguins, for instance, would be smaller than those of other birds for the fact that penguins do not use them to fly.

The second part of Lamarck's mechanism for evolution is the inheritance of acquired traits.

He believed that traits altered or acquired over an individual's lifetime could be transferred down to its offspring.

Giraffes that had acquired long necks would have offspring with long necks instead of the short necks their parents were born with.

This type of inheritance, every now and then known as Lamarckian inheritance, has since been disproved through the discovery of hereditary genetics.

An extension of Lamarck's ideas of inheritance that has stood the test of time, though, is the idea that evolutionary change occurs slowly and steadily.

He studied antique seashells and observed that the older they were, the simpler they looked. From that, he concluded that species began simple and constantly moved toward complexity, or, as he phrased it, closer to perfection.

Difference between the two theories of evolution:
Darwin depended on nearly an equivalent evidence for evolution that Lamarck did (like in the vestigial structures and selection through breeding), but made entirely different arguments from Lamarck.

Darwin did not accept a dart of complication driving through the history of life.

He argued that complexity resulted merely as a result of life adapting to its local environment from generation to generation similar to modern biologists.

Although Darwin's ideas weren't completely modern.

For instance, he started and eventually refused to accept various varying ideas regarding heredity (which includes the inheritance of acquired characteristics, as envisioned by Lamarck) and never came to any rewarding conclusion about the way traits were transferred from parent to offspring.

In spite of what Lamarck got wrong in his postulations he can be credited with visualizing evolutionary change for the first time.