Question

Based on the phylogeny of Lepidosauria, if two sister species from the _____ clade were lost to extinction, this would prune the tree only slightly and would cause only a minimal loss of phylogenetic history. But if the two species of _____ were to go extinct, this loss would prune away a piece of phylogenetic history dating back to well before the divergence of snakes and lizards.

Answer 1

Extinction of two species from the Squamata clade, which includes lizards and snakes, would minimally impact the phylogenetic tree, whereas the loss of species from the less diverse Sphenodontia clade, which includes tuataras, would result in a significant loss of evolutionary history.

Step-by-step explanation:

Based on the phylogeny of Lepidosauria, if two sister species from the Squamata clade were lost to extinction, this would prune the tree only slightly and would cause only a minimal loss of phylogenetic history. However, if the two species of Sphenodontia were to go extinct, this loss would prune away a piece of phylogenetic history dating back to well before the divergence of snakes and lizards. The Sphenodontia clade, which includes the tuatara, is far less diverse than the Squamata clade, which encompasses lizards and snakes, making the former's extinction more critical in terms of the loss of evolutionary history.