Below is the evolutionary relationships of Homo Australopith

Below is the evolutionary relationships of Homo, Australopithecus, and Pan (chimpanzees) as we currently understand them. In the blanks, write common similarities (synapomorphies) of the dental arch shared by the organisms, but differ from the other species. For example, in a. and b., what physical characteristic of teeth structure do Homo and Australopithecus share but differs from Pan? In c. and d., how is the teeth structure different between Homo and Australopithecus?

Solution

Answer:

(a) and (b):

Compared to Pan, Homo and Australopithecus possessed smaller incisors and canines, and their molars were bigger and flatter.

The enamel on their teeth was also thicker.

(c) and (d):

Australopithecus generally had medium/large teeth and are small compared to Homo.

The absolute sizes of cheek teeth expand through successively younger species of Australopithecus.