Humanlike grasp may have evolved by 6 million years ago
ALBUQUERQUE — A tiny fossil thumb bone provides a gripping look at the early evolution of human hands, according to a study presented April 16 at the annual meeting of the American Association of Physical Anthropologists.
An upright gait and a relatively sophisticated ability to manipulate objects apparently evolved in tandem among the earliest hominids at least 6 million years ago, said Sergio Almécija of the Autonomous University of Barcelona. That’s well before the earliest evidence of stone toolmaking, about 2.6 million years ago, arguing against the idea that fine motor skills for toolmaking drove the evolution of opposable thumbs.
Almécija and his colleagues studied a bone from the tip of a thumb belonging to Orrorin tugenensis. At an estimated 6 million years old, Orrorin is the second oldest hominid genus. A more recently identified hominid genus and species, Sahelanthropus tchadensis