Lec14_Origin of Novelty

Lec14_Origin of Novelty - iclicker the diagram below...

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iclicker: the diagram below illustrates… A.Cladogenesis B.Anagenesis C.Genesis D.Speciation From Kelley, 1984, Journal of Paleontology One of the earliest tests of P.E.: Miocene mollusks from Chesapeake Bay So, how common is stasis? It is present in almost all clades of animals Probably the dominant pattern in benthic marine macrofossil groups Less common (?) in protists Implications of the punctuated view ! Evolutionary rates can be taxonomic , in addition to morphological ± What causes evolutionary trends?
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“The Evolution of the Horse” W.D. Matthew (1925) O.C. Marsh (1886) A more complete evolutionary history of horses What causes evolutionary trends? Differential extinction Differential speciation – species selection – species sorting
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Barton et al (2007) Evolution PE and Phyletic Gradualism are ends of a continuum… The question is what are the relative frequencies…. Things to remember about Punctuated Equilibrium It is a theory about the distribution of evolutionary change in relation to speciation It is not synonymous with just any theory of rapid or saltational change in evolution It was originally derived from taking conventional ideas about how speciation occurs and applying them to the fossil record. It began a fundamental reassessment of macroevolution, which continues today Possible implications of Punctuated Equilibrium Most evolutionary change occurs at speciation Most species will remain relatively stable between events of speciation
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This note was uploaded on 12/20/2011 for the course BIOG 1440 taught by Professor Owens during the Spring '10 term at Cornell.

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Lec14_Origin of Novelty - iclicker the diagram below...

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