Genetic drift can result in genetic traits being lost from a population or becoming widespread in a population without respect to the survival or reproductive value of the alleles involved. Assuming the ground is a fairly consistent shade of brown, those mice whose fur is most closely matched to that color will be most likely to survive and reproduce, passing on their genes for their brown coat. WebGenetic drift that occurs when the size of a population is reduced, as by a natural disaster or human actions. 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and that adaptations enhance the survival and reproduction of individuals in a population, https://en.Wikipedia.org/wiki/Microevolution, https://www.khanacademy.org/science/biology/her/heredity-and-genetics/a/allele-frequency-the-gene-pool, CC BY-NC-SA: Attribution-NonCommercial-ShareAlike, http://cnx.org/contents/[email protected], http://cnx.org/contents/[email protected], https://commons.wikimedia.org/wiki/File:Random_sampling_genetic_drift.gif, Understand the connection between genetics and evolution, Understand how environmental changes and selective pressures impact the spread of mutations, contributing to the process of evolution, Describe the different types of variation in a population. WebModelSim Evolution Center for Connected Learning at Northwestern University Draft Copy for pilot classrooms do not cite or redistribute without permission Student Manual 1 Reading 5.2 Genetic Drift and Population Size A population bottleneck (or genetic bottleneck) are when the size of a population becomes very small. Genetic drift causes allele frequencies (versions of a gene) to fluctuate unpredictably, even if these alleles are 'neutral.'