ANTHR 102 Lecture Notes - Lecture 15: Gene Flow, Zygosity, Dna Replication
Document Summary
Exchange of genes that occurs when a given population experiences a sudden expansion due to in-migration of outsiders from another population of the species. Occurs when human groups come into contact with one another. Always occurs when genes can be changed homogenizes different populations. Increases phenotypic differences between populations: makes pop look diff from each other. Has strongest effects in small populations with non-random mating pattern. Bottleneck effect- suddenly reduced in size by disease or disaster. Genetic makeup of new population depends directly on the genotype of the reduced founding population (look like their parents). Can lead to highly divergent populations, particularly if mating is not random. A few individuals produce most of the offspring. Founder effect- small subgroups that establish themselves apart from a larger population. Mutation- creation of new allele for a gene when the portion of dna molecule to which it corresponds is suddenly altered ; new genes that nobody has = increase/new variation (during dna replication)
