A small bone from the baby finger of a human ancestor that existed more than 1.84 million years ago in the eastern side of Africa was discovered. The bone in question is the oldest “modern” hand bone ever found say scientists.
The pinkie bone / baby finger pushes back in time a key step in the process of evolution of our predecessors. They ranged from tree-climbing foragers to hand crafted tool-wielding hunters.
Further analysis of the bone also suggests that at the time of existence, more human-like creatures have been discovered to have lived at that specific point in time in the same region, one of the major hotspots that are known as the human point of origin, in Tanzania. This report came from the scientist in the journal: “Nature Communications”.
The hand is one of the most critical anatomical features that distinguish humans from beasts. Even a 3.6-centimeter, two-million-year-old fragment of a predecessor’s bone can reveal a lot about body type and behaviour.
The shape of our predecessors hands are a reflection of their stage and roll in the process of evolution says lead author Manuel Dominguez-Rodrigo, a researcher at the Institute of Evolution in Africa in Madrid.
"Our hand evolved to allow us a variety of grips and enough gripping power to allow us the widest range of manipulation observed in any primate," says Dominguez-Rodrigo.
"It is this manipulation capability that interacted with our brains to develop our intelligence, mainly through the invention and use of tools."
There are several defining characteristics with regard to the anatomy of the human hand that distinguish the differences between us and our predecessors.
One is a longer thumb, allowing us to grip more precisely and to open our hands more fully.
Another is the straightening of our phalanges, the general name given to the three bones found in each finger. Curved phalanges were adapted for climbing trees and swinging from branches.
"A modern-like hand in the past would tell us when humans became fully terrestrial and when and how efficiently our ancestors used tools," says Dominguez-Rodrigo.
That transition happened in two main stages.
After the members of the Home genus group began walking on two legs around six million years ago, the human hand evolved and included a longer thumb.