By reference to the tree above which of the following is an

By reference to the tree above, which of the following is an accurate statement of depicted evolutionary relationships? Explain your reasoning. a) A crocodile is more closely related to a lizard than to a bird b) A crocodile is more closely related to a bird than to a lizard c) A crocodile is equally related to a lizard and a bird d) A crocodile is related to a lizard, but is not related to a bird

Solution

Answer: A crocodile is more closely related to a bird than to a lizard.

The tips of the evolutionary tree represent current day species, groups of descendant taxa. The internal nodes represent the common ancestor of those descendants and the edges connect nodes to nodes and nodes to tips; their lengths may correspond to time estimates - evolutionary time. The internal node of bird and dinosaur depicts recent common ancestor while internodes of lizard and birds forms distant common ancestor.Here crocodile and bird form internode sharing common ancestor that is unique to them, they have a lot of evolutionary history in common. Crocodile and lizard are two seperate species as per evolutionary tree given above and they both share distant common ancestor at internode of crocodile, bird and lizard.