60 likes | 221 Views
BIO 110, Life Science. Summer 2012. Genetic populations. Genetic diversity over time Genetic drift Gene flow Effects of selection What this means for speciation. Phylogeny. Genealogy of asexual reproduction Genealogy of sexual reproduction Genealogy of species (= phylogeny).
E N D
BIO 110, Life Science Summer 2012
Genetic populations • Genetic diversity over time • Genetic drift • Gene flow • Effects of selection • What this means for speciation
Phylogeny • Genealogy of asexual reproduction • Genealogy of sexual reproduction • Genealogy of species (= phylogeny)
How do we discern relationship? • Every organism contains within it traces of its entire evolutionary history • Homology: similarity based on common descent • Homoplasy: false homology • Called “analogy” in the text; analogy is a specific kind of homoplasy
Reconstructing phylogeny • Shared unique homology • Monophyletic group = clade • Looking at tetrapods
Amphibians tetrapodlimb lactation, 4-ch heart, hair Mammals shell Turtles amnion Lizards no limbs Snakes Crocodiles 4-ch heart feathers Birds