Genetic Drift: Types, Effects, and Significance in Evolutionary Biology

genetic drift

A change in the allele frequency of a population as a result of CHANCE eventsmostly affects small populations

Genetic drift is a kind of evolution where fluctuations in the frequency of alleles occur in small populations due to chance events. This evolution process is based on randomness and not selection pressure. Genetic drift can occur in any population, however, its impact is most effective in small populations.

There are two types of genetic drift – Founder effect and Bottleneck effect. In the founder effect, a new population is established by a few individuals who are not representative of the larger population they come from. This can lead to a loss of genetic diversity as the new individuals may not carry all the genetic variations of the larger population. The bottleneck effect occurs when there is a drastic decline in the population size due to some catastrophic events like natural disasters or human activities such as overhunting or deforestation. In this case, only a small proportion of the original population survives and leads to a loss of genetic variation.

The effects of genetic drift can lead to the formation of new subspecies or even genus over long periods. However, in the short run, the effect of genetic drift can be random and without any discernible outcome. In some cases, while genetic drift can lead to the fixation of a favorable trait but it can also be detrimental causing the loss of important genes that were crucial for survival.

Overall, genetic drift is an important concept in evolutionary biology as it helps us understand the extent of genetic diversity in populations and how this diversity changes over time in response to various environmental factors.

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