Researchers say tooth markings can indicate whether fossil remains were right- or left-handed.
New parents are anxious to see with which had their latest arrival will soon be scrawling his or her name, and now, new research has found that handedness has been a trait for a lot longer than previously thought, according to an article on csmonitor.com.
About 9 percent of humans today use their right hand dominantly, but most other animals do not appear to have a tendency to be either right or left handed. Previous studies have found evidence of right-handedness among the Neanderthals and their relatives back some 430,000 years ago, but this latest find changes that timeline quite a bit.
Researchers have uncovered a jaw bone of a H. habilis that once roamed in what is currently Tanzania back 1.8 million years ago, and markings on the teeth indicate, at least to some researchers, the owner was right-handed.
It appears the fossil has distinctive scratches on its teeth that slant downward from left to right, giving the impression that something had been dragged across the front of the teeth.
Scientists, upon closer evaluation, speculate the markings were made by a stone tool, used to cut meat into smaller portions for chewing. They surmised the early relative used the teeth to hold one end of the meat, and the left hand to hold the other, while using the tool to saw across the meat with the right hand. When the stone tool came in contact with the teeth, it left the downward slanting marks across the dental surface.
David Frayer, a paleoanthropologist and professor emeritus at the University of Kansas, said the team found 559 marks on the fossil’s teeth, and 47 percent of them aligned with what they thought would be produced by using the tool in the described manner. Only 11 percent of the markings appeared to have been caused by a similar left-handed motion.
However, Bernard Wood, a paleoanthropologist at George Washington University, cautioned it may be too early to accept that conclusion. In the article, Wood was quoted as saying, “It’s a really interesting observation that only time will tell whether that observation has been over-interpreted.”
Frayer admitted the study of only one subject was just the beginning of a picture and more research would be needed.
The findings were published in the Journal of Human Evolution.