BIOL 304 Lecture Notes - Lecture 14: Sewall Wright, Population Genetics, Neo-Darwinism

• School: McGill University
• Department: Biology
• Course: BIOL 304
• Professor: Graham Bell

Document Summary

Dar(cid:449)i(cid:374)"s pri(cid:374)(cid:272)iple of di(cid:448)erge(cid:374)(cid:272)e (cid:373)odel: ma(cid:272)(cid:396)oe(cid:448)olutio(cid:374) is (cid:373)i(cid:272)(cid:396)oe(cid:448)olutio(cid:374) (cid:862)(cid:449)(cid:396)it la(cid:396)ge(cid:863, natural selection is slow, gradual, and continuous (microevolution) and over long spans of time can cause larger-scale phenomena: Divisions of taxonomic hierarchy above the species level. Origin of complex adaptations such as the vertebrate eye: prediction: you should see gradual transitions between small scale adaptive changes in populations to larger scale phenomena, (cid:862)natu(cid:396)a (cid:374)o(cid:374) fa(cid:272)it saltu(cid:373)(cid:863) nature does not take big jumps. Dar(cid:449)i(cid:374)"s pro(cid:271)le(cid:373) the natural world is often characterized by gaps and discontinuities. Gaps in taxonomic divisions: the 35 phyla of animals are largely discontinuous in their body plan. Mutationism: mutation theory (1903, argues that new species arise in a single step, forming a fully functional and novel phenotype, botanist who studied the evening primrose and observed discontinuous variation in the hybrids. Yuri flipchenko russian entomolgist: coins the terms micro and macro-evolution (1927, he does not see them as distinct.