What do these skulls in the fossil record tell us about hominin evolution? • The jaw grew relatively larger as hominins evolved.
The increase in size of the jaw in the fossil record provides insights into the dietary changes and adaptations in hominins over time. The jaw is responsible for housing the teeth, and an increase in jaw size would imply larger and more robust teeth. This suggests a shift in dietary preferences towards harder, tougher, or more abrasive foods.
The change in jaw size can reflect changes in masticatory (chewing) behavior, indicating a transition from a more primitive diet to a diet that included harder and tougher foods, such as fibrous plants or meat. This alteration in diet likely occurred in response to environmental changes, availability of different food sources, or as adaptations to new habitats.
Furthermore, the increased jaw size could also be related to changes in the structure and size of other craniofacial features. For example, larger jaws might be associated with a bigger cranial base, which can influence the size and shape of the braincase and thus affect brain size.
In conclusion, the larger jaws observed in the fossil record provide important information about the dietary adaptation and craniofacial changes that occurred during hominin evolution. They suggest a shift towards a more specialized diet and potentially indicate modifications in other craniofacial structures as well.