Question

Differentiate between Genetic drift and gene migration.

Answer 1

Aspect	Genetic Drift	Gene Migration (Gene Flow)
Definition	Change in gene frequency within a population due to random chance events, not due to natural selection.	Movement of alleles between populations through interbreeding.
Cause	Random chance events, especially in small or isolated populations.	Migration of individuals or gametes between populations.
Effect on Variation	Tends to reduce genetic variation within populations by loss of rare alleles; may increase variation between populations.	Increases genetic variation within populations; reduces differences between populations.
Impact on Evolution	Can lead to fixation or loss of alleles, potentially contributing to speciation via isolated populations.	Maintains genetic similarity among populations, hindering speciation.
Population Size Relevance	More significant in small populations.	Occurs in populations where interbreeding between groups is possible.
Example	Random loss of an allele if the only carrier dies before reproducing.	Transfer of alleles between neighboring populations through mating.