Who is Seeker from Time's Eye and what is their importance?

Seeker is an ape—one of a tribe of evolutionary intelligence. Though without language as we know it, Seeker walks upright with ease and is barely more than a meter in height. She has little fat and her dense black hair covers her slack skin. Her face is pulled forward in a muzzle, and she has short arms and legs. Though she looks much like a chimpanzee, her kind is already three million years farther in their development. Seeker is a true biped, her hips and pelvis resembling a human much more than any chimp.