01:119:115 Lecture Notes - Lecture 21: Genomics, Ecological Niche, Stephen Jay Gould
13 Mar 2016
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Document Summary
Species is a latin word meaning kind or appearance . Speciation- process where one species splits into two new species. Microevolution- changes over time in the alleles in a population. Macroevolution- a broad pattern where species are formed. Biological species concept- states that a species is a group of populations whose members have the potential to interbreed in nature & produce viable, fertile offspring; they do not breed successfully w/ other populations. Gene flow- b/w populations holds the phenotype of a population together. Reproductive isolation- existence of biological factors (barriers) that impede two species from producing viable, fertile offspring. Hybrids- offspring of crosses b/w different species. Reproductive isolation can be classified by whether factors act before/after fertilization: prezygotic barriers- block fertilization from occurring by: How does speciation occur: allopatric speciation- gene flow is interrupted/reduced when a population is divided into geographically isolated subpopulations. Definition of barrier depends on the ability of a population to disperse.
