Question

The evolutionary relationships between seven different species-G, H, J, K, L, M, and N-are diagrammed in Figure Q9-33.Given this information, which of the following statements is false?

(a) These are all highly related species, because the sequence divergence between the most divergent species is 3%.
(b) Species M is just as related to species G as it is to species J.
(c) Species N is more closely related to the last common ancestor of all of these species than to any of the other species shown in the diagram.
(d) Species G and H are as closely related to each other as species J and K are to each other.

Answer 1

A phylogenetic tree delineates the evolutionary relationships among species based on genetic or physical traits. It depicts which species are more closely related through common ancestors. Determining the false statement among given options would depend on the positions and distances of species nodes on the tree.

The correct option is c.

Step-by-step explanation:

In biology, a phylogenetic tree is a diagrammatic representation that shows the evolutionary relationships among various species. Based on similarity in genetic or physical traits, a phylogenetic tree outlines which species are more closely related to one another.

Given a scenario where species G, H, J, K, L, M, and N are represented on a phylogenetic tree, we could determine the closeness of their relationships—such as which species share a more recent common ancestor—by analyzing the tree.

For the statements provided about the relatedness of the species, if we imagine that species M is positioned equally distant from species G and J on the phylogenetic tree, then statement (b) that 'Species M is just as related to species G as it is to species J' would likely be true.

However, if species N is positioned closer to the last common ancestor than to any other species, statement (c) 'Species N is more closely related to the last common ancestor of all of these species than to any of the other species shown in the diagram' would also likely be true. This could signify that Species N has fewer evolutionary changes from the root, making it less related to the other species compared to their interrelations.

If a specific statement among the given options is false, it would be the one not supported by the phylogenetic relationships as indicated by the tree diagram. Determining this would require analyzing the tree's specific branching pattern and the relative distances between various nodes representing the species. It is worth noting that the evolutionary distance or number of changes in DNA — sometimes quantified as a percentage like the 3% sequence divergence mentioned — gives an indication of the relatedness too.

The correct option is c.