Many features distinguish modern humans from the nonhuman apes. However, only bipedalism and non-honing canines define hominins as a group. Identify the reasons why?

1) The proper taxonomic groups are most times always defined by the traits,these traits are the ones that are shared among members of the group eventhough they aren't found in species that are closely related.

2) The two traits are all common as they arise in the ancestors of all the hominins, however,they are not found in the nonhominins apes

3) The evolution of these hominins involved several changes that are different and that happened at different times,and only two of these features,out of all that we have evolved early enough to actually apply to all the hominins.

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.