L48 Anthro 150A Lecture Notes - Lecture 5: George Gaylord Simpson, Species Problem, On The Origin Of Species
Document Summary
Darwin published on the origin of species by means of natural selection in 1859. Ernst mayr: an important biologist in the 20th century; founder of the modern synthesis. The time period where naturalists and geneticists came together and established how their observations and the mathematics of evolution were compatible with each other. A species is a population of actually or potentially interbreeding organisms that are reproductively isolated from other such groups. Hybrid sterility is an example of reproductive isolation. Identifying isolating mechanisms is a way to tell species apart. A species is an unbroken lineage of populations linked by ancestry and descent. Difficult to apply in practice - the fossil record is incomplete. A species is a group of organisms that share a unique suite of primitive and derived traits and that is diagnosably distinct from other such groups. Anagenesis: a transformation of one species into another. Phyletic gradualism: speciation is slow, uniform, and gradual.
