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a. Define genetic drift - VCE - SSCE Biology - Question 6 - 2011 - Paper 1
Question 6
a. Define genetic drift. Genetic drift refers to the change in allele frequency in a population by chance. It is a mechanism of evolution that can lead to significa... show full transcript
Worked Solution & Example Answer:a. Define genetic drift - VCE - SSCE Biology - Question 6 - 2011 - Paper 1
Step 1
Define genetic drift
Answer
Genetic drift is defined as the change in allele frequency in a population by chance. It highlights that allele frequencies can fluctuate randomly, particularly in small populations, leading to a reduction in genetic variation. Such changes do not necessarily relate to advantageous traits, contrasting with natural selection, and can significantly impact a population's evolutionary trajectory.
Step 2
6bi. Discuss the implications of genetic drift in the Illinois prairie chicken population.
Answer
In the Illinois population of prairie chickens, several important points emerge from the presence of genetic drift:
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Fewer alleles present: The genetic variability in the Illinois prairie chicken population is likely to be reduced due to a lower number of alleles at the gene loci. This diminishes their capability to adapt to environmental changes.
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Less variation present: The limited genetic diversity increases the risk of inbreeding, which can further decrease fitness and increase vulnerability to diseases.
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Greater risk of extinction: With the combination of reduced genetic diversity and the challenges posed by environmental changes, this population faces a higher risk of extinction.
Step 3
6bi. Explain any isolating mechanisms between prairie chicken populations.
Answer
The populations may experience isolating mechanisms such as:
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Gene flow or interbreeding has occurred: There might be instances where gene flow is still happening between the Illinois population and others, which can aid in maintaining some genetic diversity.
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Isolation mechanisms: Factors such as geographical barriers or behavioral differences may prevent interbreeding, leading to distinct evolutionary paths for the populations. This could enhance genetic drift effects in isolated groups.