All early hominin metacarpal specimens generally exhibit high trabecular bone volume fraction like that of Pan and unlike that of the lower trabecular density of recent H. sapiens. However, the distribution of trabecular bone is similar to the distinct patterns of committed tool users and tool makers, H. sapiens and Neandertals.This is an excellent example of a transitional trait. They began to adapt the power and precision grips while still maintaining arboreal tendencies and retaining some of the skeletal morphology of their ancestors. One more step on the road to humanity.
Friday, January 23, 2015
Australopithecus africanus Used Power and Precision Grip
Science Daily, as well as some other outlets are reporting new research on evidence that Australopithecus africanus used their hands in the same way that we use ours. Focusing on the trabecular (spongy) bone patterns found in the metacarpals, they discovered that the wear and deposition patterns supported the hypothesis that they used their hands to perform precision and power "thumb to forefinger" tasks. This is a huge step in the direction of making stone tools and using the hands for many other daily jobs. The authors are quick to point out, however: