Question

After reading/listening to the materials from section 1, answer each of the following questions:

1. What evidence did Michel Brunet cite in order to argue that Sahelanthropus tchadensis is the earliest known representative of the hominin lineage?
2. Why are Roberto Macchiarelli and Aude Bergeret suspicious of Brunet’s interpretation? What evidence do they cite to suggest that Sahelanthropus may not have been a hominin?

Answer 1

Ans1

he team, led by Michel Brunet, now at the Collège de France, originally found six hominid specimens in Djurab Desert of northern Chad in 2001. The discovery included a nearly complete, yet distorted, skull (nicknamed Toumaï, meaning “hope of life” in the local Goran language). Although very primitive, the skull, jaw and teeth displayed some hominid-like traits.

Ans2

the species had a relatively flat face instead of a protruding muzzle like a chimp. And the tip of the canine tooth was worn down, as it is in humans. This suggested Sahelanthropus lacked a “honing” complex in which the back side of the upper canine sharpens itself against the lower first premolar (what your dentist might call a bicuspid). This appears to be a trait that hominids lost after they split from the chimpanzee lineage. In addition, Sahelanthropus’ foramen magnum—the hole at the base of the skull that the spinal cord runs through—was situated further forward than a chimp’s, implying Sahelanthropus had an erect posture and therefore walked upright on two legs.