Researchers have finally figured out why people no longer have tails.
People lost their tails, which is still one of the most noticeable changes in human history. It looks like this big change happened about 25 million years ago. It was a turning point in the development of our species and our primate relatives. There are many ideas about why we lose our tails, but the genetic reasons have been a secret until now. A groundbreaking study that was just released in the prestigious journal Nature reveals the genetics behind why our tails have gone away.1.
No Tails for People: How did we get here?
The first step in figuring out how humans lost their tails came from an unusual place. When Bo Xia, a graduate student at New York University, hurt his own coccyx (tailbone), he started to wonder where the human tailbone came from. Because they were interested, Xia and his friends set out on a scientific journey that led to a major discovery.
The researchers carefully looked into the TBXT gene, which is a key player in controlling tail length in many other species. What they found was a unique DNA change inside the gene. This is a huge step forward in our understanding of how humans evolved.
The most important part of this discovery is the part that jumping genes, especially Alu elements, play in making genetic diversity and changing evolution. These Alu elements, which are only found in primates, had an effect by becoming incorporated into the TBXT gene. This had major effects on our species and is directly related to the reason humans lost their tails.2
When Alu elements were added to the TBXT gene, they set off a chain of molecular events that led to alternative splicing, a process that had not been known about in the context of tail evolution until now. RNA molecules were cut and rearranged in a very complicated way that resulted in the loss of an important exon (any guesses?). This changed the structure and function of the protein that was made (our tails).3.
From Mice to Men: Proof from Experiments
To make sure their results were correct, the researchers genetically modified lab mice to have the same mutations that were seen in people and apes. When these mice were changed, they looked a lot like our ancestors who didn’t have tails, which is strong proof for the role of the identified genetic mutation.
But the study also showed that babies who lose their tails are more likely to have neural tube problems, like spina bifida in our case. This new information shows how complicated the relationship is between genetic changes and the possible costs and benefits of evolution.
People have lost their tails. What now?
The effects of this finding go far beyond the field of evolutionary biology. This research gives us a lot of new information about the complicated human body and health. It turns out that losing our tails wasn’t just a lucky accident, but a DNA change that had far-reaching effects.4
Every time we think about how humans evolved, we remember the complicated dance between new genes and natural selection that has shaped our history. We are still trying to figure out where we came from because we are naturally curious and have formed scientific minds.
So, we now know genetically why humans lost their tails. This is a great example of the power of scientific research and the never-ending search for knowledge. As we enjoy the progress made in finding out where we came from, we should remember that the secrets of our past hold the key to the puzzles of our future.
