Biology 1201A Lecture Notes - Lecture 8: Macroevolution, Reproductive Isolation, Speciation
14 Jul 2016
School
Department
Course
Professor
Document Summary
The origin of higher order taxonomic groups (i. e. species and beyond) Macroevolution results from the accumulation of microevolutionary changes over time. A way of differentiating and defining species based on morphology (exterior looks) Small organisms not enough phenotypic variation to group them into clusters. Phenotypic variation within species hard to distinguish which variations are important in determining different species when a lot of variation is present. Evolutionary history evolution could be random, but fundamentally, it is the basis of everything in biology; the evolutionary history is not taken into account. Groups of potentially or actually interbreeding organisms, reproductively isolated from other groups. Consequence: the gene pools (collection of all the alleles in a particular species) is isolated from the gene pool of another species. The gene pools are kept separate between species. Distinct species: when there is no mixing of the gene pool. Asexual species does not apply well to organisms that do not sexually reproduce.
