ANT101H5 Lecture Notes - Lecture 6: Ecological Niche, Allele Frequency, Cladistics
Document Summary
Human diversity is seen as the result of microevolutionary forces small changes in allele frequencies acting on the human gene pool. Vs macroevolution appearance of new species due to many generational changes in allele frequencies. Do not pass through similar stages during embryonic development. Structures possessed by 2 different organisms that arise in a similar fashion. Categorize organisms based on homologous traits cladistics. Determine ancestral versus derived (modified) homologous traits to determine lineage. Clade: a group of organisms with a common ancestor. A single ancestral species gives rise to 2 or more descendant species. A species way of life considered in the context of its environment (haviland & crawford, Rapid diversification of an evolving population as it adapts to a variety of available niches (haviland & crawford, 2009: 138) Major periods & epochs of evolution of life. Shifting limbs: beginning of separation between mouth & nasal cavity, dental differentiation. 1st mammals appeared: end of triassic period (190 mya)
