chapter 23 - What is evolution Ernst Mayr (2001) "What...

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1 How populations evolve What is evolution Ernst Mayr (2001) Æ “What evolution is” Evolution Æ “gradual process by which the living world has been developing following the origin of life” Ernst Mayr 1905 - 2005 …what is evolution Campbell’s book Æ “all the changes that have transformed life on earth from its earliest beginnings to the diversity that characterizes it today” Your instructor’s Æ “gradual process by which the universe changes; it includes the origin of life, its diversification, and the synergistic phenomena resulting from the interaction between life and the environment” What is biological evolution? Descent with modification Æ all organisms descend from a common ancestor modification Æ mutation, recombination, horizontal gene transfer Micro-evolution Æ change in the genetic make up of a population (allele frequencies) Macro-evolution Æ speciation and the development of major processes and patterns in nature process Æ speciation (e.g. reproductive isolation due to continental drift) pattern Æ geographic distribution and abundance of organisms what, how, when, where, what-for, why, who misconception Æ organisms evolve during their lifetimes = WRONG! Natural selection acts on individuals, but only populations evolve Understanding what , how , when , where , what-for , why & who of evolution: first: understand Æ evolutionary forces: migration, mutation, natural selection, genetic drift Migration Movement of individuals or gametes in ( immigration ) and out ( emigration ) a population Population A allele Population B allele migration migration
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2 Y. Wade, N. 2006. Before the Dawn. The Penguin Press, NY Y-chromosome mtDNA Stringer & Andrews 2005 M45 35,000 yrs Genealogical trees show the relationship among Y-chromosome markers. All trace their descent from M168, who lived in Africa (from Wells 2002).
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This note was uploaded on 04/16/2008 for the course BIO 131 taught by Professor Paz y mino during the Fall '08 term at UMass Dartmouth.

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chapter 23 - What is evolution Ernst Mayr (2001) "What...

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