[Campbell Biology P.603] According to Figure 26.2, what does the phylogenetic tree illustrat... | Practice Question

According to Figure 26.2, what does the phylogenetic tree illustrate regarding the "No limbs" trait in snakes and glass lizards?

  • A: Snakes and glass lizards are more closely related to each other than to geckos, due to sharing the "No limbs" trait.
  • B: The "No limbs" trait is an ancestral characteristic of the entire lizard lineage shown.
  • C: The "No limbs" trait evolved independently in the lineages leading to snakes and glass lizards, demonstrating convergent evolution.
  • D: Snakes and glass lizards share a recent common ancestor that was already limbless.

Explanation

Figure 26.2 explicitly states "Convergent evolution of limbless bodies. A phylogeny based on DNA sequence data reveals that a legless body form evolved independently from legged ancestors in the lineages leading to glass lizards and to snakes." This is visually represented by two separate 'No limbs' markings on the tree.