BIO 121 Lecture Notes - Lecture 17: Reproductive Isolation, Macroevolution, Speciation
Document Summary
Biological species concept defines species based on reproduction. Microevolution : changes in allele frequency in a population over time, and can cause speciation (leads to macroevolution) origin of plants or mammals them. Macroevolution : broad patterns of evolutionary change above the species level, like the. When talking about species, scientists now use the biological species concept to describe. Members of the same biological species are reproductively compatible w/ one another. Don"t breed this way with members of other species. Reproductive isolation is not always absolute, particularly for plants which can spread pollen and seeds great distances. Some organisms have the potential to interbreed, but never in nature. Reproductive isolation : barriers that stop or prevent two species from producing viable, fertile offspring. Barriers can be classified by whether or not reproduction is affected by the barrier before/after fertilization. Can block fertilization from occurring by stopping individuals from attempting to mate or preventing the completion of successful mating.
