Question

Refer to the above phylogenetic tree to answer this question. Lemurs can make their own vitamin C, but tarsiers, represented by the genus Tarsius, and all other primates cannot. So, according to this phylogenetic tree, when did the golup gene become a pseudogene in the history of our primate group?

1. The golup gene became a pseudogene after the emergence of lemurs.
2. The golup gene became a pseudogene after the divergence of lemurs and tarsiers.
3. The golup gene became a pseudogene before the emergence of lemurs.
4. The golup gene became a pseudogene before the divergence of lemurs and tarsiers.

Answer 1

The golup gene became a pseudogene after the divergence of lemurs and tarsiers but before the divergence of other primates, indicating the common ancestor of tarsiers and other haplorhines lost the ability to synthesize vitamin C.

Step-by-step explanation:

The student's question is about determining when the golup gene became a pseudogene within the evolutionary history of primates. Since lemurs can make their own vitamin C while tarsiers and all other primates cannot, we can infer that the loss of vitamin C synthesis occurred after the divergence of lemurs but before the divergence of tarsiers from other primates. Therefore, the correct answer is that the golup gene became a pseudogene after the divergence of lemurs and tarsiers but before the emergence of other primates. This indicates that the ability to synthesize vitamin C was lost in the common ancestor of tarsiers and the other haplorhines.