Final answer:
The key homologous traits of hominins include a brain size over 600 cc, a rounded skull with features such as a sagittal keel, reduced prognathism with smaller jaws, teeth adaptations including a relatively larger third molar, and anatomy adapted for bipedalism with humanlike feet.
Step-by-step explanation:
Key Homologous Traits of Hominins
Identifying the key homologous traits of hominins is crucial for understanding the evolutionary path that led to modern humans. The research conducted by notable anthropologists like the Leakeys provides us with specific characteristics that define our ancestors. Key homologous traits of early hominins include:
- A brain size over 600 cc, indicating increased brain volume relative to body size.
- A rounded skull that resembles that of Homo habilis or Homo erectus, as well as features like a sagittal keel.
- Reduced prognathism with smaller jaws and mandibles compared to earlier primates.
- Teeth adapted for varied diets, including the presence of a third molar that is larger than the other molars in australopithecines and some early Homo species.
- Postcranial features resembling modern humans, with an anatomy fully adapted for bipedal locomotion such as humanlike feet with arches and ankles capable of supporting a bipedal gait.