Evidence for Evolution
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Fossil record
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Shows now extinct animals
that bear resemblance to animals living today.
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Shows changes in forms of
life over large spans of time. Deepest & oldest sediments have marine
invertebrates and ever higher & younger sediments show sequence
of first appearance of fish then of amphibians then of reptiles
then of mammals.
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Shows genetic lineages from
ancestors to descendants => transitional series => "missing
links".
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Developmental and structural
remnants of past ancestry found in living species
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Embryos exhibit features of
ancestors (birds & anteaters have tooth buds, humans have lanugo =
thin coat of hair)
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Vestigial limbs and organs
(kiwi wings, useless eyes for cave dwellers, human appendix, genes for
synthesizing vitamin C are inactive "pseudogenes in humans)
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Biogeography = study
of geographic distribution of plants and animals
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Oceanic islands have bizarre
flora and fauna: Missing or impoverished in many types of animals.
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Missing animals do spectacularly
well when introduced by humans.
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Islands have "radiations"
of an ancestral species.
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Animals and plants on oceanic
islands bear greatest similarity to species found on nearest mainland.
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Kinds of organisms on oceanic
islands are those that can easily get there.
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Conclusion: Species on islands
descend from individuals who successfully colonized from the mainland
and subsequently evolved into new species.
ID and other creationism ideas argue
about #1 but are very weak on #2 and silent on #3.