Scientists have discovered how our ancestors lost their tails

Whether long, short, functional or elementary, the lot spinal cordspinal cord There is a tail. Many… but not all. Some rare groups of animals are exceptions. Among them, the hominoidshominoids, which brings together humans and some great apes. Yet very useful, this trait can improve the balance of the bearer, serve as a means of communication or defense, and even as a thermoregulator! But then, how can we explain that we no longer have any? A study published on the front page of a prestigious journal Nature

notes the key role of insertion of fragments ofDNADNA Certain – called AluY – in ShamefulShameful TBXT is associated with tail development (or not) in animals.

Have we found humanity’s famous “missing link”? Discover the story full of twists and turns of one of the most important discoveries of our existence on this planet. © Futura

Evolutionary advantage or brain anomaly?

The researchers used genetically modified mice to simulate this process. They found that inserting AluY into the mouse TBXT gene resulted in a modified version of the gene: TBXTΔexon6.

Expression of TBXTΔexon6 in mouse cells leads to reduction or disappearance of tails in guinea pigs. The results suggest that a similar event occurred about 25 million years ago, leading to the disappearance of the tail in future humans. This change GeneticGenetic This can be explained by the evolutionary advantages associated with bipedality, but can also be linked to a problem seen in certain rodents, namely a defect in the development of the neural tube, an embryonic structure that develops. central nervous system

central nervous system.