TLS Online TPP Program

#Id: 9206

#Section 3: Genetics, Cellular and Molecular Biology

Genetic drift 

Genetic drift is an evolutionary force, in which allelic frequency change over generation Just by chance (sampling error). 

The deviations from the expected ratios are random, the direction of change is unpredictable.

TLS Online TPP Program

#Id: 9207

#Section 3: Genetics, Cellular and Molecular Biology

TLS Online TPP Program

#Id: 9208

#Section 3: Genetics, Cellular and Molecular Biology

CAUSES OF GENETIC DRIFT

Genetic drift in a small population over multiple generations can significantly affect the composition of a population’s gene pool. 

TLS Online TPP Program

#Id: 9209

#Section 3: Genetics, Cellular and Molecular Biology

Founder effect

A few individuals form a population start a new population with a different allele frequency than the original population.

Sampling error can arise is through the founder effect, which results from the establishment of a population by a small number of individuals.

TLS Online TPP Program

#Id: 9210

#Section 3: Genetics, Cellular and Molecular Biology

Genetic bottleneck

Genetic drift arises is through a genetic bottleneck, which develops when a population undergoes a drastic reduction in size

TLS Online TPP Program

#Id: 9211

#Section 3: Genetics, Cellular and Molecular Biology

THE MAGNITUDE OF GENETIC DRIFT

n  = population size

pq=allelic frequency

sp2=variance in allelic frequency among the populations