A recent study by researchers at Langone Health University in New York may explain how, along the evolution of the species, humans and primates have come to a notable difference: the lack of a tail.
New gene may have caused tail loss PHOTO Shutterstock
In the evolutionary process, tail growth in early humans would have stopped starting 25 million years ago, notes The New York Post.
“Our study begins to explain how evolution removed our tails, a question that has intrigued me since I was young.”said the study's lead author, Dr. Bo Xia.
By looking at and analyzing DNA samples from humans, great apes, and other ape species, scientists discovered that the latter lack a piece of genetic code shared by the former two.
This happened not by mutation — the scientific term for changes in DNA — but by the insertion of another “fragment” of genetic code, known as AluY, in early humans and great apes during prehistoric times, according to the study published in ” The nature”.
The discovery, made for the first time, shows that the new gene affects the length of the tail. When paired with another gene, called TBXT, two types of ribonucleic acid—critical to cell structure—were formed that produced tail loss in humans and monkeys.
“This finding is remarkable because most human introns are repetitive children that end up in DNA without any effect on gene expression, but this particular AluY insertion did something so obvious such as determination lengthsyl tails”said Dr. Jef Boeke, director of the Sol and Judith Bergstein Institute for Systems Genetics.
The major evolutionary schism is also believed to have given rise to the coccyx in humans, gorillas, and chimpanzees.
However, it remains unclear why or how ancient creatures determined that tail loss was best for evolutionary survival.
Experiments with mice revealed that tail loss could also coincide with an increase in neural tube defects, which in humans can cause diseases such as spina bifida – a condition where the spine is misaligned with the spinal cord.
“Future experiments will test the theory that, in an ancient evolutionary compromise, the loss of a tail in humans contributed to congenital neural tube defects.” said study author Dr. Itai Yanai.
