Biology 1001A Lecture Notes - Lecture 18: Radiometric Dating, Continental Drift, Plate Tectonics
23 Mar 2014
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Patterns in macroevolution: the fossil record, mode and tempo evolution, evolutionary trends: changes in body size. Temporal- more likely to find new fossils than old fossils due to erosion, etc. Taxonomic- not everything is likely to fossilize. Habitat- some environments are better for fossil formation i. e. ocean good environment. 20. 6- interpreting evolutionary lineages: the evolution and adaptive radiation of horses demonstrate that many species arise and disappear, revealing that the evolution of a species is not a linear process. Possession of intermediate traits may not be evidence of direct ancestry: evolution can occur by gradual changes, by anagenesis or by cladogenesis, anagenesis- the accumulation of changes in a lineage as it adapts to changing environments. Does not increase the number of species; it is the evolutionary transformation of an existing species rather than the production of new ones: cladogenesis- the evolution of two or more descendant species from a common ancestor.
