The term “Energy” is defined as the capacity of doing work. Biological activities require energy which comes from the sun. The solar energy is transformed into chemical energy by the process of photosynthesis.
The energy flows from the sun to plants & then to all heterotrophic organisms such as microorganisms, animals & human beings. Living organisms use energy mainly into 2 forms;
Radial energy is the light energy coming from the sun.
Fixed energy is the potential energy which is found in the chemical energy of food stored in various organic substances which can be broken down in order to release their energy content.
A population of all different species occupying particular place makes up the community that is biological in the particular complex interrelation of plants, animals, and microorganism. Here ecosystem is the community of different species interacting with one another & with their nonliving environment of matter & energy.
All the earth ecosystem together make up the biosphere. Major land ecosystem such as forests, grassland and desert are called terrestrial ecosystem or biomes; major ecosystem found in hydrosphere called an aquatic ecosystem.
Large or small ecosystem, normally do not have distinct boundaries. Each ecosystem blends into adjacent ones through transition zones that contain many of the plants and animals and other characteristics found in the adjacent ecosystem.
Biosphere consists of the part of earth’s atmosphere, hydrosphere & lithosphere (earth soil) in which all living thing exist & interact.
Individuals at the base of pyramidal combination make species, next lies population then communities & exist under ecosystem. The aggregation of the entire ecosystem on the earth is sometimes referred to as ecosphere or biosphere of the whole planet. The shape may be pyramidal; the structure may be tetrahedral in nature.
Long Term Evolution of Ecosystem is Shaped By;
The first ecosystem, three billion years ago were populated by tiny anaerobic heterotrophs that lived in an organic matter synthesized by an abiotic process. Following the origin and population and explosion of an algal population which converted reducing atmosphere into organic and inorganic oxygenic organisms have evolved through the long geologic ages into increasingly complex and diverse systems that have achieved control of atmosphere and are populated by longer and more highly organized multicellular species.
From this, evolutionary changes are said to be continued.
Evolutionary change is believed to occur through natural selection, at or below the species level, & important especially because of – a) Co-evolution i.e. reciprocal selection between interdependent autotrophs and heterotrophs and b) group or community selection, which lead to maintenance of traits favorable to the genetic unit within the group.
Nature’s strategy is the successional process. Nature is not only balanced by energy but also CO2 – O2 atmosphere, gaseous exchange and self-maintaining ecosystems (homeostasis), manipulations that being concerned in regional and global balances.
The broad pattern of evolution of organisms & oxy-genetic atmosphere makes the biosphere unique. Life began to be evolved during the transition from the reducing-oxidizing environment about three billion years ago. The atmosphere was containing N2 Co2 NH3 H3 CH4 H2O (vapor) but no free oxygen (Calvin 1969) H2S Cl2 and other poisonous gasses.
There are lacking of oxygen & no ozone layer formation (but O2 acted on by short wave radiation produces O3 that absorbs UV radiation) to shield harmful extraterrestrial radiation which penetrates all the land and water that would kill exposed life supporting system.
Chemical evolution leads to the successful production of the amino acids, which is the main procreative unit of life. A small amount of oxygen in water vapor (gaseous state provided a shield against UV radiation), after the development of abundant ozone. It again creates a procreative cover for water, land and organisms such as anaerobes, yeast takes the energy for the respiration, from the fermentation process in the vents, gysors and big oceanic level. It advances the evolution of photosynthesis, brings more rapid expansion of life in the land. Oxygen becomes increased and ozone layer thickness is again increased where aerobic energy makes life more multi-cellular that was time six hundred millions years ago. During Cambrian period, a living organism such as sponges, coral, worms and fish, seaweeds , vertebrates and green plants of the sea were able to produce excess oxygen thus making the land populated in a short period of time.
This was calcareous age covering Whole Ocean with phytoplankton and at the same time, the Paleozoic era diminishing large creature dinosaur, vigor reptiles and increasing the types of mammal than human beings when oxygen was about 20 percentage in the biosphere, and it would success in the heterotrophic succession followed by autotrophic succession. Here, some fluctuations in oxygen – carbon dioxide level occur. In this era, carbon dioxide becomes bloomed. Larger reptiles and dinosaur were disappeared and climatic changes occur because of the larger difference in temperature or extra-terrestrial harmful radiation or autotrophic evolution bloom again.
Oxygen and carbon dioxide balanced stage atmospheric condition have appeared due to extraterrestrial radiation, food, and energy imbalance, each creating oscillating steady state or puzzled state of nature, but the complex existing living system being procreated with time and old become extinct. Surviving species manage to persist genetic composition and in abundance without change. It is the period if neo-Darwinism theory which suggests all the evolutionary change can be explained by conventional natural selection mutation theory.
Simpson’s (1969) concludes that community or group evolution in the ecosystem not at in stabilized or that may be due to reciprocal selective interaction between two major groups or that may be due to reciprocal selective interactions between two major group or communities or more with a close ecological relationship such as plants and herbivores, large organisms and micro-organisms, parasite and host, predators & preys, carbon dioxide & oxygen that may bring finally co-evolution of biosphere and enhancing further evolution of balance state of biosphere, which is known as balance of nature.
E.p., Odum. Fundamentals of Ecology. USA: W.B Saunters Company, n.d.
Jr., Miller G.T. Living in the Environment. Belmont, California, USA: Wadsworth Publishing Company, 2003.