The common belief of today is that the last common ancestors of humans and apes were the size of chimpanzees. Now, researchers studying the human family tree found that the last common ancestors of early humans and apes are likely primates that are as small as gibbons.
Last Common Ancestor Of Humans And Apes
Tracing the origins of humanity is quite the complicated subject. It's difficult enough to map out the dispersal of hominids, and even more so to dig the roots of our lineage. The common understanding to date is that the chimpanzees are the likeliest candidate for the last common ancestor of humans and the great apes. However, a new study suggests that contrary to previous belief, a smaller primate the size of modern-day gibbons may be our likeliest last common ancestor.
A new study published in the journal Nature Communications details the study of a pair of researchers from the University of Tübingen and the University of Stony Brook in New York. By studying primate fossil samples from Africa, Europe and Asia, researchers found that the body mass of our last common ancestor suggests living in an environment favorable to a gibbon-sized creature. That is about 11 pounds (5 kg) and perhaps 17 to 25 inches in size, similar to modern gibbons.
Ancient Family Tree
Hominoids, including all great apes and eventual humans, separated from the lineage of New World monkeys about 25 million years ago, creating a line of hominoids and Old World monkeys. From there, the lineage continued to develop over the next millions of years.
"The lineage that led to the gibbons was the earliest hominoid to diverge from the group that led to the great apes and humans, about 17 million years ago," writes the statement from the University of Tübingen.
Body Mass Evolution
As suggested in their findings, the researchers state that contrary to the common belief that primates developed overhand hanging and swinging because they had become too heavy to walk on top of tree branches, it appears as though the swinging and hanging movements developed first before the body mass increase later on.
What's more, they believe that the common understanding that early human evolution involved only either staying the same size or increasing in size may not be so, as they also found evidence of size decrease in the process of our lineage's evolution. Such changes are believed to be possibly caused by a multitude of factors such as environmental factors, and others such as tool use and food availability.
Basically, the researchers found that the human evolution process did not come in a straight line and was not as simple as just getting bigger over time.
Learning From The Past
Though we continue to press forward into a vastly more technologically advanced future, knowing how our species came to be remains an important part of understanding humanity and how, perhaps, we are all related to each other and the creatures around us.