University of Central Florida (UCF) ANT2511 The Human Species Practice Exam 1

Genetic drift is a mechanism of evolution that refers to random changes in allele frequencies within a population. This phenomenon is particularly pronounced in small populations because, in such groups, random events can have a more significant impact on the genetic makeup over generations.

When a population size is small, each individual's genetic contribution is proportionally larger, which means that if any individual happens to pass on traits that differ from the wider gene pool, those traits can become more common (or entirely lost) due to chance. This is unlike larger populations, where the random loss or fixation of alleles might not significantly affect the overall genetic diversity.

Consequently, small population size creates an environment where genetic drift can lead to a reduction in genetic variation, potentially resulting in inbreeding and increasing vulnerability to environmental changes or diseases. This concentrated effect makes genetic drift an essential consideration in conservation biology and the study of evolution within small or isolated populations.