Speciation

SPECIATION defined as the creation of two or more new species from one ancestral species. Allopatric speciation most common type of speciation involves geographical isolation gene flow is interrupted when population is divided into geographically isolated subpopulations isolation might occur because of great distance, etc. Sympatric speciation no geographical isolation emergence of a reproductive barrier isolates a subset of the population gene flow may be reduced by such factors: polyploidy, habit differentiation, and sexual selection i.e.: Northern Spotted Owl and Mexican Spotted Owl

Terms Geographical isolation defined as when the ancestral species are separated geographically and thus, over time, cannot interbreed anymore. Hybrid zones may be formed when allopatric populations come back into contact with one another region in which members of different species meet and mate, and maybe produce offspring of mixed ancestry has three possible consequences: Reinforcement cannot interbreed most common Fusion can interbreed and produce offspring can form new species offspring cannot interbreed with parent species Stability can interbreed and produce offspring can form new species offspring can interbreed with either of the parent species Macroevolution evolutionary patterns on a larger scale patterns: Stasis i.e. coelacanth Mass extinction i.e. mammoth Adaptive Radiation i.e. Pundamilia Coevolution i.e. blue butterfly