Why Did Humans Lose Their Tails?

Reach behind you and put a finger at the very base of your spine. Right at the bottom, below where your belt sits, past the last vertebra you can easily feel. There is a small hard point there. Most people have never deliberately touched it. That is your tail. Not a metaphor and not the place a tail used to be. The actual thing: three to five vertebrae fused into a single wedge of bone, sitting at the end of your spinal column exactly where a tail attaches on every animal that has one. It has muscles connected to it that in a cat are the ones that lift the tail and swing it. In you they hold your pelvic floor together, which is a job, but it is not the job they were built for. So the question is the wrong way round. You did not lose your tail. You grew one, and then, before anyone ever saw you, you took it apart. Around the fourth week after conception a human embryo has a tail with ten to twelve vertebrae in it, curling round behind the body. In week five it can be longer than the leg buds that become your legs. Then the cells in it begin to die on purpose, on a schedule, from the tip inwards, the same way the gaps between your fingers were carved out of solid tissue. By week eight the outside of it is gone. Every human being does this. There is no version of a person who skips it. The reason it happens at all is much older, and it was only worked out properly in twenty twenty four. Apes lost their tails around twenty five million years ago, which is long before we walked upright, long before stone tools, and long before our line split from chimpanzees. Every explanation that starts with coming down from the trees is wrong on the dates alone, and gibbons live in trees today with no tail at all. What actually happened is that a piece of self-copying junk DNA landed inside the gene that builds tails, next to another piece already sitting there. The two stuck together, folded the gene in half, and the instruction came out short. Nothing adapted. Something jumped, landed badly, and the tail stopped. What's in this one The coccyx: three to five fused vertebrae you can feel right now What a tail actually is, which is just more spine past the hips The tail you grew in week four and dismantled before you were born Apoptosis, and why your fingers were carved out of a solid paddle The hard line: every monkey has one, not one ape does Proconsul, an ape twenty million years old with the vertebrae simply stopping Why the coming-down-from-the-trees explanation fails on the dates Alu, TBXT, and the piece of junk DNA that folded a gene in half The mice engineered with the ape version, and what they were born with The cost: neural tube defects, and the spines that still fail to close The tailless cat breed from an island, and the same trade made twice Human babies born with tails, and what that proves is still switched on Why nobody selected for this, and why it stayed anyway You are not an animal that lacks a tail. You are an animal that builds one and then removes it, every single time, and has been getting away with that for twenty five million years. Sources Xia et al., On the genetic basis of tail-loss evolution in humans and apes, Nature, 2024 Ward, Walker and Teaford, Proconsul did not have a tail, Journal of Human Evolution, 1991 Nakatsu, Uwabe and Shiota, Neural tube closure in humans initiates at multiple sites, Anatomy and Embryology, 2000 Fallon and Simandl, Evidence of a role for cell death in the disappearance of the embryonic human tail, American Journal of Anatomy, 1978 Saraga-Babic et al., Development of the human tail bud and its regression, Acta Anatomica, 1994 Howell et al., Pathogenic mutations in the T-box transcription factor and Manx taillessness in the domestic cat, Mammalian Genome, 2013 Dagosto, The origin and diversification of anthropoid primates, in Anthropoid Origins, 2004 Ledbetter and Bruck, Vestigial caudal appendage in the newborn, a review of the reported cases, Journal of Pediatric Surgery, various If you want more of these, why humans lost their fur is here [VIDEO URL], and why we are the only human species left is here [VIDEO URL]. #humanevolution #anatomy #ancienthumans #evolution #biology #anthropology #science