Why humans no longer have tails

Let’s delve into the fascinating discovery about why humans no longer have tails.

Around 25 million years ago, an evolutionary split occurred between our ancestors (the precursors of humans and apes) and monkeys. This divergence resulted in the loss of tails in our lineage. However, the genetic mutation responsible for this significant transformation remained elusive until recently.

Geneticist Bo Xia and his colleagues embarked on a quest to unravel this mystery. They identified a genetic change shared by humans and other apes that might have contributed to their ancestors’ tail loss. This pivotal mutation occurred approximately 25 million years ago.

Here’s the key insight: Humans and apes carry a particular gene called TBXT, which has extra letters inserted into it. This mutation is absent in monkeys and other primates with tails. The insertion in TBXT leads to a shortened form of the protein it encodes. This alteration affects tail development, resulting in the absence or shortening of tails in our lineage.

To validate their findings, the researchers meticulously worked with gene-edited mice. These mice, carrying similar alterations to their genomes, exhibited short or absent tails. The study was published after nearly 900 days of rigorous work, demonstrating that the genetic changes indeed had the predicted effect123.

In summary, this groundbreaking research sheds light on the ancient genetic mutation that shaped our species, leaving us without tails. It’s a testament to scientific persistence and curiosity!