A recent study conducted by university researchers revealed that human hands may be more primitive than we thought.
Around 2.6 million years ago, our ancient ancestors used stone tools to perform their daily tasks. These items were crafted by chipping away at large rocks, and such a process was thought to be the start of human hand evolution since tool craftsmanship required great dexterity.
Given the nickname "handyman," one human ancestor named Homo habilis was deemed as the first ancient toolmaker to begin the journey to our modern-day hands. Various activities that it undertook such as hunting, foraging, and cooking all required the use of stone equipment.
As a result, researchers believed these endeavors equally contributed to the evolution of the human hand.
Yet, a recent study performed by researchers at the University of Kent and Chatham University found otherwise. By using a pressure system called Pliance, the team was able to measure the pressure exerted by each human finger when performing these ancient, survival activities. Volunteers were asked to crack nuts, chip stone flakes to create tools, and acquire marrow from bones using a hammer.
What interested the team was the varied pressure readings.
Instead of each pursuit requiring the same amount of pressure from each finger, the thumb, index, and middle fingers were the most used. This suggested that primates who had longer versions of these fingers were more capable of performing survival activities and lived longer as a result. By surviving longer than, they could pass their genes to their children and resultantly contribute to today's humankind.
In terms of the activities themselves, the act of acquiring bone marrow outshined the rest. It required the most amount of pressure while nut-cracking required the least. Such information explained why ancient primates who only relied on nuts and soft plants to survive did not have humanlike hands. These findings also revealed just how important bone marrow was to the development of our ancestors.
Bone marrow was a filling and delicious meal for many species in the past; however, it required an intense amount of labor to obtain. Arguably, the act of acquiring bone marrow allowed for the complexity of the human hand to transpire. Those that had the strength and thumbs long enough to reach inside and access the marrow lasted longer and passed their genes down to their offspring. New genes arose in those next generations, and the beneficial ones were passed down again. The cycle repeated, and thus, the human hand was eventually born as each ancestral generation contributed a small nuance to its structure to perfect it.
By looking at the makeup of ape and monkey hands, scientists concluded they had longer fingers and shorter thumbs that allowed them to grip and swing on trees with ease. Humans, however, had longer thumbs to accurately grasp onto more things and pick up smaller objects.
An earlier study in 2015 found that this human quality closely resembled the hands of the common ancestor who connected us to our nonhuman relatives. Thus, the human hand was seen as more "primitive" in structure even though it was more advanced in its abilities.
The journey is far from over, however, as more studies continue to explore this topic and draw new conclusions.
But at the core of our most effective attribute, researchers have found there lies a soft substance tucked away in the depths of our bones that allowed only the most capable to survive.
Through centuries of refinement, it helped our dexterity grow, and thus, enabled us to execute the most intricate tasks.
Soon enough, our abilities expanded, and we became an intelligent species capable of surviving and beyond.