No- Some forms remain ancient forms and hardly change (e.g. the coelacanths, unchanged for 200mya), can also happen in plants (e.g. ferns, conifers, flowering plants)
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Describe the findings of Westoll (1949)
Scored numerous fossil specimens of lungfish for 21 characteristics, this showed a period of rapid evolution for about 50my then relative stasis until present-- So evolution does not always proceed at a slow constant rate within species or lineages
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How can fossil records be used as evidence for evolution?
Complexity of organisms increases throughout Tim, oldest rock strata con only contain simple organisms
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How can lineages be used as evidence for evolution?
Fossil forms in chronological order can sometimes form obvious lineages showing cumulative changes, for example horses skulls and hooves
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What is an evolutionary arms race?
Where 2 organisms evolved against each other, e.g. grass increases silica deposition in cell walls (tougher) so horses developed larger bodies, longer jaws, increased tooth enamel
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How can embryonic development be used as evolutionary evidence?
Mammalian embryos look very similar at early stages, hox genes that control development are widely shared and therefore presumed to be ancient
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Other cards in this set
Card 2
Front
Describe the findings of Westoll (1949)
Back
Scored numerous fossil specimens of lungfish for 21 characteristics, this showed a period of rapid evolution for about 50my then relative stasis until present-- So evolution does not always proceed at a slow constant rate within species or lineages
Card 3
Front
How can fossil records be used as evidence for evolution?
Back
Card 4
Front
How can lineages be used as evidence for evolution?
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