BIO220H1 Lecture Notes - Lecture 14: Traumatic Insemination, Frequency-Dependent Selection, Damselfly
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BIO220H1 Full Course Notes
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Lecture 14 (march 8, 2016): evolution of sexual differences. Males and females share their autosomes, so over 90% of the genes are shared. Expression of shared genes in tissues differs between the sexes: gonads. In flies, 50-90% of the genes in the fly genome are expressed differently. Conspicuous ornaments (sexual dimorphism: male birds are pretty and have ornaments. Frigate bird: evolutionists care about why there is variation in nature, widow birds. Male looks very similar, while the males are very different and extravagant: variation across species in the birds is driven by the variation between males and females. Males have a cool plumage, inflate sacs, and do a dance to attract a mate. Armaments: for many ungulates, males have antlers and horns to do battle with, females prefer males with longer eye stocks, elephant seals compete with each other to dominate a beach.
