Live Science reported that recently, researchers have discovered genetic clues about why humans do not have tails even though tens of millions of years ago, the common ancestors of humans and all primitive species had tails.
According to a new discovery published on bioRxiv in September and not yet evaluated equally, scientists have identified a jumping gene associated with tail development that may have jumped to another location in the gene set of a truong species millions of years ago. Because of that, it has created a breakthrough that makes us lose our tail.
Traces of the tail
In fact, the human body still retains the trace of the tail when it is in the embryo stage. The tail is a characteristic that can originate from the first vertebrate animal on Earth, so when the human embryo develops, we will have a tail attached to the spine in the early stages of development, just like all other vertebrate animals. But after about 8 weeks, most of the ends of the human embryo are completely gone, according to a scientific study published in the journal Nature in 2008.
The only trace left of these lost tails on the human body is about 3 or 4 vertebrae that form the tail bone.
Sometimes there are cases where humans are born with a tail, but it is especially rare. A study published in 2012 in the Journal of the Indian Journal of Pediatric Surgery found that this tail is an excess part of an egg and is often a fake tail, not a real one. The fake papaya is covered with a layer of skin, containing muscles, nerves, blood vessels and connective tissue, but has no bones and cartilage and is not connected to the spinal cord like a real tail.
New York University Grossman Medical School (NYU) graduate student Bo Xia, lead author of the latest study published in September, said that the earliest known taxon of humans and homelands is the truong of Proconsul, which lived in Africa during the Miocene era (from 23 million to 5.3 million years ago) and showed no signs of tailbonearves. But the loss of the human tail is believed to have originated earlier, about 25 million years ago, when the hominoid lineage of humans and hominids separated from the Ancient World monkey family.
After comparing genetic data from 6 hominoid species and 9 monkey species, looking for differences that may be related to having or not having a tail, the team discovered a candidate that was likely to appear in a short section of DNA called the Alu element - a type of DNA that can jump from one location to another in the gene set and affect protein production - in the TBXT gene, the gene that regulates tail development. This sudden change is in the gene of humans and reptiles, but not in the gene of monkeys.
Researchers then used CRISPR gene editing technology to recreate this change in the TBXT gene in mice. As a result, the experimental mice changed their gene to have tails but had different lengths, from normal to no tails. Although the dot bien affects their tails, it is not an on/off switch, showing scientists that other genes in primates also contribute to the disappearance of the tail. However, the appearance of this breakthrough "may be an important event" disrupting the tail creation process - according to research co-author Itai Yanai, professor at the Department of Chemistry and phanoline Pharmacy of New York University.
The effect of losing a tail
Researchers report that losing a tail may have helped monkeys and beginners move to walk on two legs, an inevitable development that coincides with no tail.
The loss of the species occurred about 25 million years ago, long before our smart race Homo sapiens walked on Earth. For millions of years since then, the genetics of tail development in human race have stopped working, and all the parts needed for tail development have long been lost. Therefore, it is unlikely that one day humans will have a tail again.
Michelle bezanson, a professor of anthology at the University of Arts and Sciences in Santa Santa Santa Santa Claus in California, who was not involved in the study, said that tailors are beneficial in other ways, and these secondary parts perform various useful functions such as orienting the body during jumps, helping to maintain balance and stability when moving or eating. Even their tails are used to express social behavior, such as the South American titans belonging to the parent species Callicebus tying their tails together with their lover as a way to express affection.
