Question

Natural selection can, through common descent, produce closely related species that have similarities due to their shared ancestry. Natural selection can also, through convergent evolution, lead to distantly related species appearing very similar. Identify which examples reflect common descent and which reflect convergence.

Answer 1

Complete Question:

Natural selection can, through common descent, produce closely related species that have similarities due to their shared ancestry. Natural selection can also, through convergent evolution, lead to distantly related species appearing very similar. Identify which examples reflect common descent and which reflect convergence.      

• Tree-dwelling primates have prehensile tails for gripping branches.

• Tree-dwelling opossums also have prehensile tails.  
• Many birds and some kinds of bats that feed on plant nectar all have long flexible tongues.    
• Primates use opposable thumbs to help climb. New World monkeys also have prehensile tails, but Old World monkeys do not.  
• Marsupial mammals throughout Australia show a wide diversity of forms that reflect the habitats in which they live.
• Hawaiian honeycreepers, with their elongated, nectar-sipping bills, all evolved from a finch-like ancestor.

Answer and Explanation:

• Tree-dwelling primates have prehensile tails for gripping branches.  Considering recent ancestors, the prehensile tail trait can be considered as a convergence example that occurred among different groups. But we can also think about it as a common descent if we consider the farthest primates ancestor. Although still controversial, Plesidiapsi might be considered a common ancestor of primates, that evolved from a ree-dwelling mammal with a long tail. It is believed that this animal used to live in trees.  
• Tree-dwelling opossums also have prehensile tails.   Convergence.
• Many birds and some kinds of bats that feed on plant nectar all have long flexible tongues. Convergence. These are two groups that are very separated from each other, and they developed different traits according to their needs separately. Some of the species of these two groups adapted to feed on the same plant so they needed to develop the same characteristic to obtain nectar.
• Primates use opposable thumbs to help climb. New World monkeys also have prehensile tails, but Old World monkeys do not.   Common descent . The common ancestor had a prehensile tail, some of the descendants developed the tail but some others did not.
• Marsupial mammals throughout Australia show a wide diversity of forms that reflect the habitats in which they live.  Common descent .
• Hawaiian honeycreepers, with their elongated, nectar-sipping bills, all evolved from a finch-like ancestor.  Common descent . They all look like the finch-like ancestor.