How Humans Lost Their Tails (Published 2021) (2024)

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How Humans Lost Their Tails (Published 2021)? ›

A single genetic tweak caused human ancestors to lose their tails 25 million years ago — but it came at a cost. Scientists have found a mutation in our DNA that snipped our tails off. The mutation may have allowed our ancestors to walk upright. But it may also be behind a birth defect that still affects babies today.

Following this evolutionary split, the group of apes that includes present-day humans evolved the formation of fewer tail vertebrae, giving rise to the coccyx, or tailbone. Although the reason for tail loss is uncertain, some experts propose that it may have better suited life on the ground than in the trees.

Humans lost their tails about 25 million years ago, but scientists have now discovered what caused the mutation during the process of evolution. The discovery has been made by researchers from New York University Langone Health.

In a new study published Wednesday (Feb. 28) in the journal Nature, researchers identified a unique DNA mutation that drove the loss of our ancestors' tails. It's located in the gene TBXT, which is known to be involved in tail length in tailed animals.

The new discovery suggests our ancestors lost their tails suddenly, rather than gradually, which aligns with what scientists have found in the fossil record. The study authors posit the mutation might have cropped up randomly in a single ape around 20 million years ago and gotten passed on to its offspring.

Researchers have shown that humans and other apes carry a DNA insertion in a gene called TBXT that other primates with tails, such as monkeys, don't have. And mice carrying similar alterations to their genomes have short or absent tails. “They clearly show that this change contributes to tail loss.

Around 20-30 million years ago, the branch of apes that would eventually evolve into humans evolved away from having tails. A team at New York University identified a particularly interesting mutation that likely played an important part.

We will likely live longer and become taller, as well as more lightly built. We'll probably be less aggressive and more agreeable, but have smaller brains. A bit like a golden retriever, we'll be friendly and jolly, but maybe not that interesting.

In general, the giraffe is the winner with a tail that averages about eight feet in length. In terms of sheer size, however, blue whales have the largest tail (just as they have the record for size of virtually every other body part), which is the size of a soccer net.

It might sound like a tall tale, but in very rare cases, humans can be born with boneless rear-end appendages, sometimes up to 18 centimeters long. To date, official records have tallied about 40 babies born with 'true tails', consisting of soft, boneless, finger-like protrusions that are easily removed via surgery.

Why do humans have a tailbone but no tail? ›

Over time as a species, however, we evolved past the need for such an organ, which is why the majority of humans no longer grow them. Most humans grow a tail in the womb, which disappears by eight weeks. The embryonic tail usually grows into the coccyx or the tailbone.

A new study suggests that an ancient genetic change helps to explain why apes and people do not have tails, but monkeys still do. A team of scientists says it may have pinpointed the genetic mutation that contributed to tail loss.

Human tails are a rare entity. The birth of a baby with a tail can cause tremendous psychological disturbance to the parents. They are usually classified as true and pseudo tails. [1] Tails are usually associated with occult spinal dysraphism.

[4] During the 5^th to 6^th week of intrauterine life, the human embryo has a tail with 10–12 vertebrae. By 8 weeks, the human tail disappears. The persistent tail probably arises from the distal nonvertebrate remnant of the embryonic tail. [5] True human tail arises from the most distal remnant of the embryonic tail.

There are only 40 cases of true human tails reported in literature, hence this condition warrants review. [1] This condition usually presents in newborns, causes anxiety and fear in parents, hence it is brought to medical attention very early.

WASHINGTON (AP) — Our very ancient animal ancestors had tails. Why don't we? Somewhere around 20 million or 25 million years ago, when apes diverged from monkeys, our branch of the tree of life shed its tail. From Darwin's time, scientists have wondered why — and how — this happened.