Question

What is meant by coalescence?

1) The process of tracing homologous alleles back to a common ancestor
2) The history of an allele within a population
3) The point in the history of a genetic locus when it becomes polymorphic
4) All of the above
5) None of the above

Answer 1

Coalescence refers to the process of tracing the genealogical history of homologous alleles back to a common ancestor within a population, which includes understanding their diversification over time and their contribution to genetic diversity.

Step-by-step explanation:

The term coalescence in the context of population genetics refers to the process of tracing homologous alleles or gene variants back to a common ancestor, which can be seen as the genealogical history of that allele within a population. This involves understanding how alleles have separated, duplicated, and mutated over time, becoming distinct, yet still possessing a common lineage.

Within population genetics, coalescence is key to studying the genetic diversity and structure of populations, including the mechanisms that cause changes in the alleles and genotypic frequencies, such as gene flow, genetic drift, and natural selection. When considering a genetic locus, the point at which it becomes polymorphic or contains multiple alleles in a population can be seen as an aspect of coalescence, as it reflects the history and diversification of the alleles at that locus.