BIOL3044 Lecture Notes - Lecture 31: Heterosis, Epistasis, Inbreeding Depression
Document Summary
Dominance: heterozygosity of hybrids can sometimes lead to an increase in fitness. Epistasis: recombination in hybrids can disrupt sets of genes that work well together, resulting in a decrease in fitness. Dominance and epistasis are separate processes but they"re not mutually exclusive it"s not either/or going on at the same time. Variation: takes both processes into account and tries to examine how much each of these processes contributes to the fitness of hybrids across different timeframes and different spatial scales. Main topic: how hybridization can increase amount of variation available for selection to act on in a group of hybrid progeny. They can both occur even in the same cross even though they have opposite effects. In a plant: chamaecrista fasciculata an annual plant in the legume family: easy to work with and make crosses with. Researchers chose 3 target populations spanning about 2000km across the range of the species: maryland, illinois, kansas.
