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 of lemur, Eulemur rufus and Eulemur ruffon, on the island of Madagascar. These predictions were based on the environmental needs of each species. Then, the scientists determined the actual distribution of these species of lemur on the island of Madagascar. Figure 2 shows the scientists' results. 05.1 Using Figure 2, give three conclusions you can make about the distribution of these lemur species. 1 2 3 05.2 Using all the information, suggest how speciation happened to produce two species of lemur. 05.3 Suggest one precaution needed when marking the lemurs to make sure the estimate of the number of lemurs is valid. 05.4 Using the information provided, calculate how many lemurs in the second sample were marked.

Photo AI

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.

96%

114 rated

Answer

Eulemur rufus was predominantly found above the river, indicating a preference for higher elevations.
The actual distribution of Eulemur rufus closely aligns with the predicted distribution, suggesting the model used was accurate in reflecting environmental needs.
The overall distribution patterns show slight deviation from expected distributions, highlighting potential environmental changes affecting lemur habitats.

Step 2

Using all the information, suggest how speciation happened to produce two species of lemur.

99%

104 rated

Answer

Geographical isolation likely occurred, separating the two populations by physical barriers such as rivers or mountains, preventing interaction.
Reproductive isolation followed, meaning that even if populations came into contact, they could not mate and produce fertile offspring, further differentiating the species.
Different selection pressures in the distinct environments would then lead to natural selection favoring traits that suited each species to their specific habitats.

Step 3

Suggest one precaution needed when marking the lemurs to make sure the estimate of the number of lemurs is valid.

96%

101 rated

Answer

To ensure accuracy, scientists should ensure that the marking method does not harm the lemurs or alter their natural behavior.

Step 4

Using the information provided, calculate how many lemurs in the second sample were marked.

98%

120 rated

Answer

Using the mark-recapture method:

Let M = number of marked lemurs, C = number captured in the second sample, R = number of recaptured (marked) lemurs.

From the first sample, suppose M = 30. In the second sample, C = 25. If scientists estimated N (total number of lemurs) = 250, then:

The proportion of marked to total should equal the proportion of recaptures to total in the second sample:

$\frac{M}{N} = \frac{R}{C}$

Substituting the known values gives:

$\frac{30}{250} = \frac{R}{25}$

Solving this yields:

$R = \frac{30 \times 25}{250} = 3$

Thus, 3 lemurs in the second sample were marked.

Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1

Worked Solution & Example Answer:Lemurs are small mammals - AQA - A-Level Biology - Question 5 - 2022 - Paper 1

Using Figure 2, give three conclusions you can make about the distribution of these lemur species.

Using all the information, suggest how speciation happened to produce two species of lemur.

Suggest one precaution needed when marking the lemurs to make sure the estimate of the number of lemurs is valid.

Using the information provided, calculate how many lemurs in the second sample were marked.

Join the A-Level students using SimpleStudy...