Photo AI
Rock wallabies, Petrogale lateralis pearsonii, on Pearson Island off the coast of South Australia have had no genetic contact with mainland rock wallabies since they were isolated by rising sea levels at the end of the last glacial period, around 10,000 years ago - VCE - SSCE Biology - Question 8 - 2004 - Paper 1
Question 8
Rock wallabies, Petrogale lateralis pearsonii, on Pearson Island off the coast of South Australia have had no genetic contact with mainland rock wallabies since they... show full transcript
Worked Solution & Example Answer:Rock wallabies, Petrogale lateralis pearsonii, on Pearson Island off the coast of South Australia have had no genetic contact with mainland rock wallabies since they were isolated by rising sea levels at the end of the last glacial period, around 10,000 years ago - VCE - SSCE Biology - Question 8 - 2004 - Paper 1
Step 1
Explain how a genetic bottleneck may lead to a decrease in genetic diversity.
Answer
A genetic bottleneck occurs when a population experiences a severe reduction in size due to environmental events or human activities. This drastic decrease leads to a loss of alleles within a gene pool, as only a limited number of individuals contribute to the subsequent generations. Over time, this can result in reduced genetic diversity because of the limited allele frequencies that result from chance events, making the population more vulnerable to diseases and environmental changes.
Step 2
Suggest one reason for the wallabies’ success despite the lack of genetic diversity within the population.
Answer
One reason for the wallabies' success could be their adaptation to the specific environmental conditions of Pearson Island. They may have developed traits that allow them to thrive in their isolated habitat, and without significant changes in the environment or introduced predators, their population can remain stable.
Step 3
Give one reason for this suggestion.
Answer
One reason for suggesting the release of individuals from the southern Western Australian populations is to enhance genetic diversity. Introducing new individuals can increase the genetic variation within the Pearson Island population, potentially improving their adaptability to changing environmental conditions and resilience against diseases.