BIOL359 Lecture Notes - Lecture 7: Synonymous Substitution, Directional Selection, Red Queen Hypothesis
28 Apr 2017
School
Department
Course
Professor
Document Summary
Mendels law: first law: random segregation, alleles at single locus segregate randomly, 50/50 chances: second law: independent segregation: alleles at different loci segregate independently. Chromosomal inversions: all genes contained within inversions become linked, and get inherited as entire block independently and are inherited together. If genes are really close together, they"re linked and do not segregate. It can reduce genetic variability because it"s less diverse, but recombination and outcrossing can break up lineage and add diversity back into genes. Muller"s ratchet: accumulation of deleterious mutations in asexual organisms which result in lower fitness, no out crossing; ends up with deleterious mutations remaining and lowering fitness, and accumulates from one generation to the next. Example: c. elegans: outcrossing and evolutionary arms race. Red: (evolution) initial exposure to bacteria, ends up in increase in outcrossing rate - individuals are outcrossing more due to exposure to bacteria to increase genetic variation, offspring likely able to survive against bacteria.
