About 25 million years ago, our ancestors saw their tails disappear. Geneticists have just figured out how.
- The coccyx is located at the lower end of the spine.
- It is a vestige of the tail of our ancestors.
Contrary to what one might imagine, our ancestors did not lose their tails over long years of evolution, but all of a sudden. This is what discovered Itai Yanai’s teamdirector of the institute of computational medicine, specialist in biochemistry and molecular pharmacology.
To do this, the researchers compared the variants of 31 genes involved in the development of the tail in monkeys with or without this organ. They then discovered that in hominids (a branch we share with gorillas, orangutans and chimpanzees), a gene called TBXT was brutally disrupted in its evolution, causing the tails of these primates to suddenly disappear. .
A selection of evolution that remains mysterious
If researchers have discovered the cause “technical” of the loss of our tail, nobody knows today why this mutation was selected by evolution. Some argue that the tail disappeared when primates began to move upright, but fossils show that the first tailless monkeys still walked on all fours.
Living without a tail should in any case have significant advantages to compensate for the serious consequences observed when the removal of this appendix was carried out on other species: this evolution has indeed led to many serious anomalies of the spine during tests. made on mice by researchers, resembling what is now called spina bifida, an anomaly of fetal development that causes serious neurological sequelae.
.
