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28 Cards in this Set
- Front
- Back
- 3rd side (hint)
Darwin
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1) species change over time
2) natural selection causes the changes |
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adaptation
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1) process by which adaptive traits are aqcquired by evolutionary mechanisms
2) traits that enhance the survival & reproductive success of their bearers |
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population genetics
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-apply Mendel's laws to populations of orgs
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gene pool
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the sum of all alleles in a population
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autotrophs ; heterotrophs
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-self-feeders ; other-feeders
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genus
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group w/ a recent common ancestor
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species
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- a specific type; no natural interbreeding
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systematics
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the scientific study of the diversity of organisms
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taxonomy
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under systematics, classifying organisms
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Phylogeny
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- a hypothesis that describes the history of descent from a common ancestor of a group of organisms
- phylogenetic tree each node / split = speciation event |
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homologous
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features shared by 2 + species from a common ancestor
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derived trait
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a trait that differs from its ancestral form
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convergent evolution
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traits that were independently evolved become superficially similar b/c of similar selective pressures
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evolutionary reversal
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reverting back to ancestor state from derived state
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homoplastic traits / homoplasies
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traits that are similar not b/c of inheritance from common ancestor
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ancestral traits vs derived traits
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only traits in ingroup are derived; ancestral traits in ingroups and outgroups
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Evolutionary Agents causing HWE deviation
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1) Mutations
2) Migration 3) Genetic Drift 4) Nonrandom Mating 5) Natural Selection |
5 things
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mutations
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-are rare for each loci, but so many loci that there may be a few mutations in each zygote
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migration
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produces gene flow
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genetic drift
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the random loss of indivs and the alleles they possess
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population bottlenecks
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occasional periods a normally large pop. may go thru when only a small # of indivs. survive
-may increase/decrease an allele freq lots by chance being a bigger factor |
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founder effect
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a few indivs colonize region;
resulting change in genetic variation |
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nonrandom mating
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-like x like or like x unlike
-ie 2 flowers - pin (long stigma, short stamen/anther), thrum (short stigma, long stamen/anther) |
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natural selection
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when some indivs contribute more offspring to the next generation than others, changing allele freqs
-fitness - contribution of one relative to the phenotype of another |
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natural selection, quantified 3 ways
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1) stabilizing selection - avg. favored
2) directional selection - R or L 3) distruptive selection - both extremes |
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stabilizing selection
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-favors average indivs
-reduces variation |
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direction selection
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-indivs of one extreme are favored
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disruptive selection
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indivs at both extremes favored
-results in bimodal distribution -ie bill sizes in black-bellied seedcracker of W. Africa |
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