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Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1
Question 5
Lemurs are small mammals. Lemurs live in trees and feed on leaves and fruit. Scientists used a computer program to predict the expected distribution of two species o... show full transcript
Worked Solution & Example Answer:Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1
Step 1
Using Figure 2, give three conclusions you can make about the distribution of these lemur species.
Answer
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Eulemur rubriventer is primarily found below the river in the region depicted.
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The actual distribution of both species shows a similarity to the expected distribution based on environmental needs.
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It appears that the actual distribution of Eulemur rufus is slightly less than the expected distribution.
Step 2
Using all the information, suggest how speciation happened to produce two species of lemur.
Answer
Speciation likely occurred due to geographical isolation, leading to allopatric speciation. Once the lemur populations were separated, reproductive isolation mechanisms, such as differing mating behaviors, developed. Over time, the two species faced different selection pressures in their respective environments, further reinforcing their divergence.
Step 3
Step 4
Using the information provided, calculate how many lemurs in the second sample were marked.
Answer
Using the mark-recapture formula:
Given that the total population is estimated at 250, and 30 were marked in the first sample, we can set:
Where x is the number of recaptured marked lemurs. By solving, we find that approximately 3 lemurs in the second sample were marked.