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Name the type of mutation that occurred 7500 years ago in central Europe - VCE - SSCE Biology - Question 7 - 2020 - Paper 1
Question 7
Name the type of mutation that occurred 7500 years ago in central Europe. i. The increase in frequency of the allele for lactase persistence happened relati... show full transcript
Worked Solution & Example Answer:Name the type of mutation that occurred 7500 years ago in central Europe - VCE - SSCE Biology - Question 7 - 2020 - Paper 1
Step 1
Step 2
The increase in frequency of the allele for lactase persistence happened relatively quickly in some populations. Explain why the frequency of this allele increased relatively quickly.
Answer
The frequency of the allele for lactase persistence increased quickly due to several key factors:
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Selective Advantage: Individuals who could digest lactose had a nutritional benefit in environments where dairy was a significant part of the diet, which gave them a selective advantage over those who could not digest lactose.
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Higher Reproductive Success: People with the mutation likely had more offspring, as they were better able to survive and reproduce in agricultural societies that relied on milk as a food source.
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Genetic Drift: In smaller populations, random changes in allele frequency can lead to an accelerated increase in the frequency of the lactase persistence allele.
Step 3
Give two reasons for the absence of the mutation in these populations.
Answer
There are several reasons for the absence of the mutation in certain populations:
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Dietary Dependence: Some populations do not rely on dairy as a primary source of nutrition, leading to no selective pressure favoring the lactase persistence allele.
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Genetic Variation: In populations that historically did not consume milk, the lack of this allele may be due to genetic drift or other demographic factors that influenced the gene pool.