Answer:
A cladogram begins with a common ____Ancestor_________ of all the organisms represented above.
Explanation:
A cladogram is a type of diagram which is used to show their relationship between some organisms on the basis of some structural feature.
It is not like phylogenetic tree which is used to show the evolutionary history and relationships between organisms.
In a cladogram, different organism are related to one organism which is known as ancestor and cladogram begins from here.
