01:119:115 Lecture Notes - Lecture 21: Reproductive Isolation, Macroevolution, Sexual Reproduction
21 Jul 2019
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Document Summary
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, macroevolution. The biological species concept = species is a group of populations whose members have. Gene flow between populations keeps genotypes similar: limitations of the bsc. Potential to interbreed in nature and produce viable fertile offspring. Species is defined by its niche (role in the environment) Reproductive isolation = barriers that impede two species from producing viable, fertile. Hybrids = offspring of crosses between different species. Reproductive isolation can be classified by whether factors act before or after fertilization offspring and creation of a zygote. Two species encounter each other rarely or not at all because they occupy different habitats. Species that breed at different times of the day, different seasons or different years cannot mix their gametes.
