Humans and baboon have noses with nostrils that face downward, but many other primates have noses with nostrils that face out to the sides. Humans and baboons are also more closely related to each other than they are to primates with outward-facing nostrils. Therefore, the fact that both humans and baboons share the downward-facing nostril orientation is an example of

a shared derived trait.

Explanation:

Genetics can be defined as the scientific study of hereditary in living organisms such as humans, animals and plants.

Simply stated, a trait refers to the specific features or characteristics possessed by a living organism. It is essentially transferred from the parent of a living organism to her offspring and as such distinguishes him or her.

Heredity refers to the transfer of traits (specific characteristics) from the parent of a living organism to her offspring through sexual reproduction or asexual production. Some examples of hereditary traits are dimples, tongue rolling, baldness, weight, handedness, freckles, curly hair, hair color, blindness, complexion, height, etc.

All humans and baboons are created having noses with nostrils underneath i.e facing downwards but other primates such as platyrrhines have their nostrils facing sideways (face out to the side). Also, humans and baboons shared close similarities with each other when compared than they share with the primates having a outward-facing nostrils.

This ultimately implies that, both humans and baboons sharing the downward-facing nostril orientation is an example of a shared derived trait.

A shared derived trait can be defined as a trait or characteristic that is shared between two lineages and subsequently evolves leading up to a clade, which is a distinguishing feature from other species.