BIOLOGY 3 Lecture Notes - Lecture 4: East Los Angeles College, Parapatric Speciation, Reproductive Isolation
Document Summary
Adaptations (morphological, physiological, behavioral) relative to environment that help organisms survive and reproduce. Most important factor that holds a gene pool of a species together and prevents speciation gene flow. Macroevolution- origin of new taxonomic groups (e. g. , species, genera, families, phyla, etc. ) Microevolution- change in allele frequencies that occurs over time within a population. Speciation- bridge between microevolution and macroevolution, origin of new species. It is the keystone process of macroevolution and the generation of biodiversity; can be gradual (i. e. , too slow to be observed directly) or rapid. Either way, it is too rapid to be well documented in the fossil record. two basic patterns of speciation displayed in fossil record: Anagenesis- earlier population is considered a separate species from the later population. This generally occurs over long periods of time and is a pattern often seen in the fossil record. This is the accumulation of changes associated with the transformation of one species into another over time.
