Question

Define the following with one example for each: A) Genetic Drift. B) Natural selection. C) Reproductive isolation.

Answer 1

(A)variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or do not reproduce.it is called genetic drift.
(B)the process whereby organisms better adapted to their environment tend to survive and produce more offspring. The theory of its action was first fully expounded by Charles Darwin, and it is now regarded as be the main process that brings about evolution.
(C)the inability of a species to breed successfully with related species due to geographical, behavioral, physiological, or genetic barriers or differences.

Answer 2

(i) Genetic drift: It refers to the random change in gene frequencies in a small population, presumably owing to change rather than natural selection, thereby providing diversity without any adaptations.

(ii) Natural selection: In this new suitable traits are selected to live in the prevailing environment.

(iii) Reproductive isolation: When same members of a particular species are not able to mate with other members of the same species due to environmental barriers or due to other geographical barriers, it is known as reproductive isolation.