Question

What are the 4 evolutionary processes? Describe them, how does each contribute, and which dominate and under what circumstances?

In essay format please! :)

Answer 1

The four evolutionary processes are natural selection, genetic drift, mutation, and gene flow.

Natural selection: Some particular traits give better survival and reproductive rate to some individuals and such traits are passed from generation to generation and are called the natural selection of that trait. Natural selection favors survival of the fittest. Evolution acts by natural selection by giving better reproductive and genetic quality to individuals and make them survive better in an environment in future.

Genetic drift: Changes in gene frequencies due to a random event. One example of genetic drift is Founder's effect. One small population separate from a large population. New population will be having lesser gene variability. In contrast to natural selection, environment or adaptive pressure will not drive genetic drift. The effect of genetic drift is higher in smaller population and lesser in a larger population.

Mutations: These are spontaneous random changes in genetic content occur within individuals of the population. It helps to emerge new traits in a population. Mutations can be neutral, beneficial or deleterious. Neutral mutations are neither beneficial nor deleterious. Deleterious mutations reduce the fitness of the individual and cause disease. While beneficial mutation increases reproductive success and the fitness of the organism. The beneficial mutations are fixed in a population through natural selection if it is helping the individual to successfully reproduce and attain sexual maturity.

Gene flow: Gene flow occurs when a new individual enter a breeding population and contribute its genes to that gene pool. The introduction of new alleles brings genetic variability and will allow for a new combination of traits in the population. Horizontal gene transfer helps in gene flow in bacteria and plants which is a transfer of genetic material from one organism to another by means of the asexual method.