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Using Figure 2, give three conclusions you can make about the distribution of these lemur species - AQA - A-Level Biology - Question 5 - 2022 - Paper 2
Question 5
Using Figure 2, give three conclusions you can make about the distribution of these lemur species. 1 2 3 Using all the information, suggest how speciation hap... show full transcript
Worked Solution & Example Answer:Using Figure 2, give three conclusions you can make about the distribution of these lemur species - AQA - A-Level Biology - Question 5 - 2022 - Paper 2
Step 1
Using Figure 2, give three conclusions you can make about the distribution of these lemur species.
Answer
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E. rufus is primarily located in the northern region of Madagascar, suggesting it thrives in this area more than in others.
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E. rufus is also found above the river, indicating a preference for habitats located in higher elevations or specific environmental conditions.
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The actual distribution of both lemur species is closely aligned with their expected distribution, signifying that environmental factors influence their presence.
Step 2
Using all the information, suggest how speciation happened to produce two species of lemur.
Answer
Speciation in lemurs likely occurred through geographical isolation, which kept populations separated from one another. Over time, with limited gene flow, each population experienced different selection pressures due to their distinct environments. This led to variations in physical characteristics, possibly through mutation, which improved survival in their respective habitats. Eventually, these differences became significant enough that the two populations could no longer interbreed, resulting in the development of two distinct species.
Step 3
Suggest one precaution needed when marking the lemurs to make sure the estimate of the number of lemurs is valid.
Answer
One important precaution is to ensure the marking method does not harm or affect the survival of the lemurs, which would result in an inaccurate estimate of the population.
Step 4
Using the information provided, calculate how many lemurs in the second sample were marked.
Answer
To calculate the number of marked lemurs in the second sample, we can use the mark-recapture method. If 30 lemurs were marked initially and then 25 were captured in the second sample where it was found there are 250 lemurs in total, we can set up the proportion:
Let M be the number marked in the second sample, then:
( \frac{M}{25} = \frac{30}{250} )
Cross-multiplying gives:
( M \cdot 250 = 30 \cdot 25 )
( M \cdot 250 = 750 )
Dividing both sides by 250:
( M = 3 )
Thus, 3 lemurs in the second sample were marked.