Biologists have found evidence for mass extinction events in Earth's history at approximately 65 million years ago (mya) and at approximately 200 mya - VCE - SSCE Biology - Question 36 - 2015 - Paper 1
Question 36
Biologists have found evidence for mass extinction events in Earth's history at approximately 65 million years ago (mya) and at approximately 200 mya. The fossil rec... show full transcript
Worked Solution & Example Answer:Biologists have found evidence for mass extinction events in Earth's history at approximately 65 million years ago (mya) and at approximately 200 mya - VCE - SSCE Biology - Question 36 - 2015 - Paper 1
Step 1
decreased mutation rates associated with the extinction event
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Answer
After a mass extinction, mutation rates may stabilize due to reduced environmental pressures, allowing existing genetic variations to flourish. This can lead to increased adaptation and speciation.
Step 2
increased numbers of fossils produced by the extinction event
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Mass extinctions often lead to an increase in the number of fossils found in sedimentary layers, providing researchers with a clearer picture of biodiversity and facilitating the study of newly emerging species.
Step 3
populations of species returning to their pre-extinction event size
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Post-extinction, surviving species often undergo population rebounds, filling ecological roles that were previously vacant, thus contributing to greater diversity.
Step 4
the extinction of many species providing many unoccupied niches
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Mass extinctions clear out established species, subsequently opening up ecological niches. This allows for rapid diversification as new species evolve to fill these available roles in the ecosystem.
