Bio; Lecture 06; Evolution

Bio; Lecture 06; Evolution - Evidence supporting Evolution...

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Evidence supporting Evolution Comparative anatomy, embryology, and development o Related organisms have homologous trits, ontogeny recapitulates phylogeny, homeobox genes o Homologous Structures Structures found in multiple species in which function may be different, but the basic structure is similar and comes from the same ancestor Example: arm of human, leg of cat, fin of whale, and wing of bat All have different function Structure is similar however—share the same skeletal elements Homologous structures diverged from a common ancestor Homologous structures show species that are phylogenetically related by a common ancestor Homology : similarities in characteristics resulting from common ancestry—although these traits function differently o Analogous Traits Species have structures that have similar function , but they have a completely different structure . Due to convergent evolution : species that lived and evolved under similar ecological pressures, but come from a different ancestor. o Homologous structures vs. analogous structures Homologous species share a common ancestor and are phylogenetically related The ancestor species diverged and split into two environments The two populations experience different environmental factors and pressures that cause them to evolve differently Results in structures with modified function but similar basic
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This note was uploaded on 05/26/2008 for the course BIO 103 taught by Professor Potts-santone during the Spring '07 term at Northeastern.

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Bio; Lecture 06; Evolution - Evidence supporting Evolution...

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