Final answer:
French scientist Michel Brunet challenged the theory that early humans originated in East Africa by discovering the fossil remains of Sahelanthropus tchadensis in Chad, Central Africa in 2001.
Step-by-step explanation:
French scientist Michel Brunet challenged the theory that early humans originated in East Africa by discovering the fossil remains of Sahelanthropus tchadensis in Chad, Central Africa in 2001. This finding provided evidence that humans may have originated in Central Africa rather than East Africa. Sahelanthropus tchadensis is an early human ancestor that lived about 7 million years ago, making it one of the earliest-known hominins.