Question

In the figure below, consider the possibility that the iguana shares a recent common ancestor with the beaver. In the iguana's lineage, hair, mammary glands, and gestation were lost. The principle of _____ suggests that this tree is not the best hypothesis about how the taxa are related.

A. increasing complexity
B. parsimony
C. evolutionary progress
D. evolutionary irreversibility

Answer 1

Evolutionary irreversibility suggests that the tree is not the best hypothesis for the relationship between the iguana and the beaver.

Step-by-step explanation:

The principle that suggests the tree is not the best hypothesis about how the taxa are related when considering the possibility that the iguana shares a recent common ancestor with the beaver is evolutionary irreversibility.

Evolutionary irreversibility suggests that once a trait is lost in a lineage, it cannot be regained in later descendants. In this case, the loss of hair, mammary glands, and gestation in the iguana's lineage would suggest that these traits cannot be regained in the beaver lineage, making them less likely to share a recent common ancestor. The principle of evolutionary irreversibility therefore indicates that the tree is not the best hypothesis for the relationship between the iguana and the beaver.