Question

What is Genetic Drift ? Give examples

Answer 1

• Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error).
• Genetic drift occurs in all populations of non-infinite size, but its effects are strongest in small populations.
• Genetic drift may result in the loss of some alleles (including beneficial ones) and the fixation, or rise to100\%100%100, percent frequency, of other alleles.
• Genetic drift can have major effects when a population is sharply reduced in size by a natural disaster (bottleneck effect) or when a small group splits off from the main population to found a colony (founder effect).

Examples:

• Of the two pink monkeys in the world – one male, one female – the female dies, ensuring that there will never be a pure-bred pink monkey again.
• A random succession of births results in all other hair colors going extinct within a village full of redheaded people.
• The freckled dazzle-flower exchanges genetic material with a small population of un-freckled dazzle-flowers. After a few seasons, there are no un-freckled dazzle-flowers left.
• The last green-eyed person in a small town dies, leaving only brown-eyed and blue-eyed people.