Adaptive evolution results from the propagation of advantageous mutations through positive selection.This is the modern synthesis of the process which Darwin and Wallace originally identified as the mechanism of evolution . However in the last half century there has been considerable debate as to whether evolutionary changes at the molecular level are largely driven by natural selection or …
Microevolution is the change in allele frequencies that occurs over time within a population. This change is due to four different processes: mutation selection gene flow and genetic drift. This change happens over a relatively short amount of time compared to the changes termed macroevolution. Population genetics is the branch of biology that provides the mathematical structure for the study of the process of microevolution. Ecological genetics concerns itself with observing microevolution in
In natural populations natural selection (adaptation mechanism) gene flow and mutation combine to change allele frequencies across generations. Genetic drift causes changes in allele frequency from random sampling due to offspring number variance in a finite population size with small populations experiencing larger per generation fluctuations in frequency than large populations.
Population genetics – Wikipedia
Microevolution – Wikipedia
Allele frequency – Wikipedia
Adaptive evolution in the human genome – Wikipedia
Genetic drift is the change in the frequency of an existing gene variant in a population due to random sampling of organisms. The alleles in the offspring are a sample of those in the parents and chance has a role in determining whether a given individual survives and reproduces. A population’s allele frequency is the fraction of the copies of one gene that share a particular form. Genetic drift may cause gene …