For quite some time now, reports about evolution have said that humans are primates, a diverse group comprising approximately 200 species.
Unlike most primates, though, a ScienceAlert report specified, humans are "tailless." It's a good thing, though, too. Today's humans ought to be thankful for such a change.
However, the question, "what if everything all went quite differently?" Other than needing a hole in the back of the pair of jeans, this report shows how the world might appear had the ancestors kept their tails. Technically speaking, all humans had one, briefly long before they were born.
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Much like the new and old-world monkeys, tarsiers, lemurs, and bush-babies at present, these animals had an extremely long tail, perhaps, to help them keep their balance while treading through the treetops.
Short Tails in Human Development
Short tails are a trait of human development, briefly developing by approximately the sixth week of gestation. This small extension of the spinal column even has up to a dozen vertebrae.
Half of these vertebrae within a fortnight, with the other half fuses into the bone, also known as the "coccyx or tailbone," as detailed in Spine-Health.com.
Since nature loves a bit of assortment, for some reason, some humans, most of them males, are born with this embryonic tail's tip still in place.
The attachment comes complete with sufficient blood vessels to keep it healthy and even muscles that, in some instances, can make it move. What can't be found in them are any of the original vertebrae.
Contradicting protrusions from various cancers or lesions, such as vestigial "true tails," are rare in human births. One would be hard-pressed to discover more than several dozens of them in medical research.
Still, they do take place. Most are quickly taken out surgically soon following delivery, being very tiny to serve many purposes and possibly enticing unwanted attention. It would be a different story if all humans had a long tail.
The Appearance of Primates 20 Million Years Ago Minus Tails
Within 10 million years of comet thrashing dinosaurs into oblivion approximately 66 million years back, small mammals with the primate's physiology appeared.
Much like the new and old-world monkeys, tarsiers, lemurs, and bush-babies at present, these animals had an extremely long tail, perhaps, to help them keep their balance while treading through the treetops.
Over time, some of these tails developed to act as a sort of extra thumb that gained a level of dexterity most humans would desire to have. In fact, it was quite handy that it appeared in two primate groups on separate occurrences.
Unfortunately for humans, roughly 20 million years back, a group of primates appeared minus tails. Their offspring include gorillas, orangutans, bonobos, and chimpanzees, not to mention humans, as well.
Had Human Ancestors Kept Their Tails
One can only speculate why human ancestors fared so much better when its tail negated to develop.
The entire event is even more astonishing when the change that has put humans at increased risk of developing neural-tube deformities that expose the spinal cord following birth like a "spina bifida" is considered. Therefore, it must have been a considerable advantage to let the tail end go.
According to the Centers for Disease Control and Prevention, spina bifida affects the spine and is typically obvious at birth.
More than a simple extension that hangs from the spine's end, tails are attached in serious anatomical constructions surrounding the hip part.
Together, such bones, muscles, and ligaments pull the body into alignment, allowing balance and an ability to grip and control in some monkeys' cases.
This would be no tiny change. Tailed primates are inclined to have more extended spines with a couple more vertebrae to offer flexibility to slip skillfully through the branches.
On the other hand, Apes have musculoskeletal specializations with shorter lumbar sections stiffening their spines. Tougher backs can take a fall or jump's brunt better, possibly opening the way for larger bodies or rapid leaps into low branches, as well as descents to the ground.
Related information about humans having tails is shown on Mr. Compare's YouTube video below:
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