Migration drift and selection have all had a powerful effect

Migration, drift and selection have all had a powerful effect shaping human populations. Explain why it can be so difficult to distinguish between these forces when examining genotype/allele frequencies.

Solution

Genetic drift: - This term define the frequency of change in gene of a population. Here allele defines the nature of evolution weather it happened for survival or re-production. Genetic drift causes the complete or partial disappearance of gene.   

Migration: - Migration of individual or population happens resources are limited to use. To accomplish that desire the individual/population move from one place to another. This can’t be basis on gene change.

Selection: - Selection of individual in population not defined by own preference. That happens on bases of fitness and nature of adaptation. Here we can’t determine the change in allele. These mechanisms of evolution are not linked with migration and genetic drift.

As above we explained the three terms which were found unrelated in term of allele frequency. An allele represents dominance and recessive behavior of a gene. This behavior of allele expresses the nature of change in term of evolution.