Natural selection is one of the fundamental mechanisms of evolution in addition to migration, genetic drift and mutation. (Evolution 101, 2008). There are a number of factors which are vital in making up the theory of natural selection as stated: The main objective of all species is reproduction, survival and being able to pass on their genes down the generations. As their populations increase, there will be lack of adequate resources to support them therefore due to the competition for the resources some will perish. The ones perishing are those not fit for the competition for survival in the prevailing conditions. The other organisms which survive usually have some genetic compositions which will enable them to survive and thus only the superior organisms will be left to continue reproducing (Biology Online, 2000).
Biodiversity is the multiplicity of living things on this planet at all the ranks, right from the genes of organisms to whole ecosystems, and the various ways in which they all depend on one another and the ecological processes and evolutionary procedures that create and put up the ecological systems which are referred to as the biomes (Connexions, 2008). These are featured by the ways in which the inhabiting organisms adapt to them and it is the existence of these organisms on which the ecosystems depend and therefore it is evident that this diversity of organisms on earth has been very instrumental in evolution.
Studies in evolution have shown that in a situation whereby there is huge diversity in a particular genus or family, then its chances of being able to endure any adverse environmental changes will be much higher (Trowbridge J, 2003). In this regard it is evident that to a great extent, evolution is dependent on biodiversity. In the recent years man has made a big, perhaps the biggest contribution towards the changes occurring in the environments and the effect has been that many organisms, both flora and fauna, have found the rate of change brought about by man to be unbearable and this has led to their demise. The main reason for this is the interference with the diversity o the living things on earth as they cannot adapt to the changes.
Since different organisms are suited for different purposes within an ecosystem, biodiversity offers ecological stability in an ecosystem and therefore when the variety of organisms in an ecosystem reduces, there are some important roles which are not preformed and this leads to hardships for other organisms and finally their extinction if they cannot adapt to the situation.(Importance of Biodiversity, 2008) Biodiversity is important in helping to stop possibilities of gene erosion. This is a situation whereby many species may vanish from an ecosystem. This may be occasioned by changes in their ecosystem.
In a biologically diverse ecosystem, there are multiple organisms which are all supported by more or less the same kinds of resources. The more the organisms in a particular ecosystem, the more there will be interdependence amongst them thus leading to higher survival rates of the offspring (Trowbridge J, 2003). This may not be the case for a long period of time, since slowly the populations will start growing higher and putting pressure on the support system. This high diversity will mean that competition among the organisms will also be much more complicated and more intense. This will therefore mean that the environment will be adverse thus necessitating adaptation of these organisms to the prevailing conditions. The ones which are not able to adjust will either have to migrate or die off. The result of such a situation is that there will be newer organisms which, due to the ecological conditions presented by the biodiversity, have changed to enable them survive further. This is in contrast to a situation where there might be fewer organisms inhabiting an ecosystem. With less competition for the supporting resources, there will be no urge or impetus for adaptation, one of the fundamentals for evolution.
References
- Biology online. 2000. Theory of Natural selection. Web.
- Connections. 2008. Definitions of Biodiversity.
- Evolution 101.2008. Natural Selection. Web.
- Jennifer Trowbridge. 2003. Serendip. The Significance of Biodiversity: Why We Should Protect the Natural Environment.