Human hands ‘less evolved’

In what is being considered the best challenge to Darwin’s Theory of Evolution, scientists from the United States and Spain have declared that humans might just have more primitive hands than chimpanzees. It can thread a needle, coax intricate melodies from the keys of a piano, and create lasting works of art with a pen or a paintbrush.

This has been seen as one of the most distinctive traits of humankind and is often cited as one of the chief reasons for our success as a species.

Human hands may be less evolved than those of chimpanzees, research suggests. The findings have important implications for the origins of human toolmaking, as well as for what the ancestor of both humans and chimps might have looked like.

In effect, chimps and orangutan hand proportions have evolved whereas human and gorilla hands have changed very little. These findings indicate that the structure of the modern human hand is largely primitive in nature, rather than the result of selective pressures in the context of stone tool-making. In fact, human-like hands – which have long thumbs compared to their fingers – may goes as far back as 6 million years. This even included the ability to press the thumb against the fingers with considerable force, a key aspect of precision gripping.

The researchers measured the hand proportions of humans, living and fossil apes as well as fossils of human ancestors including Ardipithecus ramidus and Australopithecus sediba, to understand the step wise evolution of the hand. In a report in Science magazine, Adrienne Zihlman, a primatologist at the University of California, said the study builds an “evolutionary scenario based on one data point, bony proportions of hands, with the underlying assumption that they tell a story”.

Anatomical analysis shows that thumb-to-finger ratio is much the same in very early humans, people living today, and gorillas, suggesting a link with a dextrous common ancestor. Before, many believed that human beings started out with chimp-like hands but these eventually groomed over time as humans started using tools for daily chores.