Concluding remarks

The theory of evolution is a powerful scientific thought. It is based on a large volume of data (evidence). Evolution explains both the unity and diversity of life. It is based on a simple premise: variation of traitsin a population, and forces (natural selection) that favours specific variations over others.

The selective force may be natural (e.g. predation, disease, competition) or artificial (e.g. selective breeding). Both types of selective forces have a similar outcome: individuals that possess certain traits will survive to produceoffspring with those traits, while others will perish. This simple idea explains why populations change over a period of time. This is what Darwin meant by‘decent with modification’.

In the absence of a selective force, populations can continue to change because of other factors, such as genetic drift and migration. These factors alter the gene pool, and as such, affect biological variation in a population. Biological variations are important in a population. Studies have shown that genetically homogeneous populations are at risk of crashes or extinction. This is particularly true of asexually-reproducing populations, where genetic diversity is minimal.

The Darwin-Wallace model of evolution is a grand idea. To quote Darwin, evolution has produced“endless forms most beautiful ..”.

Sham Nair 2014