Biology 1001A Lecture Notes - Lecture 16: Hybrid Swarm, Parapatric Speciation, Meiosis
Document Summary
Microevolution: changes of allele frequencies within a population (genetic drift, natural selection, sexual selection, mutations, etc. ) Macroevolution: concerned with a generation of new species. Morphological species concept (msc): species are identified as organisms that look the same to one another. Problems with msc: when a lot of phenotypic variation occurs in a single population, it becomes problematic to classify species based on their phenotype. Biological species concept bsc: defines species as a group of actually or potentially interbreeding organisms, reproductively isolated from other such groups, not based on how you look, based on who you have sex with. It has more explanatory power than the msc; species are common because they share a common gene pool. It is also more observably testable than the msc. If they would not breed under normal conditions, or if their offspring are fertile; they are not considered the same species (example: lions + tigers = ligers)