Why don’t humans have a tail


Evolutionary process: Why don’t humans have a tail, even though they have a tail bone. Have you ever looked at your back and wondered where our tail is. You may find this a joke or a question that a child asks innocently. But this is a serious matter for scientists. Because if humans and monkeys are so biologically similar to each other, why do monkeys have tails but not ours? “It’s a better strategy,” said Bo Xia, who is studying stem cell biology at New York University’s Grossman School of Medicine. In the animal kingdom, tails can have many benefits.

They first appeared in living things about 500 million years ago and have had several roles since then. They help the fish to swim, the birds to fly and the mammals to balance. It can also be a weapon like a scorpion or a warning sign like a retail snack snake. In primates, such as monkeys, monkeys and similar animals, the tail adapts to the environment. In the United States, for example, howler monkeys have long tails and can hold things with their tails. But primitive families of humans, chimpanzees, and guerrillas are extinct in hominids. Questions of why and how have puzzled scientists for decades. Apparently, the answer lies in a recently discovered genetic mutation that affected the genes that make up the hominid tail 25 million years ago.

And not only that, but this change persisted and continued from generation to generation, making a difference to the movement of the Hominids. Maybe that’s why humans walk on two legs. “It’s all seemingly interconnected and happened at the same evolutionary time, but we didn’t know anything about the role of genetics at this stage of development and evolution,” says Shia. “As you can imagine, this is one of the most important points in evolution that makes us human.” Some animals, such as cats, help maintain balance through the tail. And to prove his point, Shia introduced the same genetic mutation into mice. They noticed that the rats began to develop different types of tails. Some had small tails, some had no tails at all.

Mystery of tail and legs

Charles Darwin had already said that. He said that modern man, Homo sapiens, is associated with apes. He authored a book, The Origin of Man, in 1871, in which he explained that the theory of evolution applies entirely to mankind. It was a great revelation of that time because the distance between humans and animals has always been visible. We live in houses, our skin is different and we use our brains to solve complex problems. By this time, Darwin had already shaken the foundations of science by writing a book called The Origin of Species.

Until then, most Western scientists had the idea that God created all living things on Earth, so Darwin’s claim about mankind was shocking. But humans and chimpanzees have a common ancestor and their DNA is 98% similar. Some 20 million years ago, the hominids that emerged were missing tails. So if tails are related to the evolution of monkeys and humans and it also made a difference in movement and body shape, then the question is, do tails come first or legs? “It’s like the question of eggs and chickens, and as you may be wondering, the answer is not easy,” says Shia. According to the theory of evolution, humans and monkeys have the same ancestry.

The short answer is that it is almost impossible to know what caused our ancestors to stand on two legs, and did the lack of a tail cause it? Or that our tails are not because we stand up straight and it is easier to balance our legs? “We need a time machine to know all this so that we can go back to the past and observe and analyze the events of that time,” says Bo Xia. But since we don’t have a time machine, I can tell you we don’t know, and the debate is over. So one might wonder why we are talking about this after all. “The correct answer is that these two stages are always discussed together.” So we can’t talk about human evolution without mentioning tails or standing on both legs, no matter which of them came first.

Related: the 6 animals that look scary but not really dangerous.

Is genetics the answer

Two years ago, while traveling in Oberoi, Shia’s wrist was injured. This question has been running through their minds ever since. This bone called the coccyx is the last part of our spine. This bone, made up of four seals that merge into each other, traces the existence of our tail millions of years ago. If you look at pictures of human embryos, you will see a tail that goes inside the embryo after a few weeks and becomes part of the spine. Charles Darwin revealed that the theory of evolution applies to humans as well The hip bone, which supports the hips, is located where the tails of other animals are.

Aitai Enai, director of the Institute of Computational Medicine at New York University, says: ‘We consider all these issues because we are interested in human science and find answers here. We have made great strides in genetic science over the last 100 years. He says: ‘You really need to know a lot of concepts, including comparative genetics and alternative supply. And Bo has proven that if you understand these concepts, you can look inside the genome and understand it. The genetic mutation that Shia has discovered contains 300 genetic characters in the middle of a gene called TBXT. This part of the DNA is practically the same in humans and monkeys. To test the relationship between this genetic mutation and the tail, Xia introduced the same genetic mutation in mice, and found that the mice did not produce normal tails.

But this is probably the first study of genetic mutations in our ancestors. Scientists say the tails of animals depend on more than 30 genes, and New York University researchers have so far studied only one. And, as Shia puts it, all human tail bones are the same, but in this experiment, rat tails were either born of different lengths or disappeared completely. Shias have come to the conclusion that this was not just a genetic mutation, but a whole series that affected different genes in the hominids 25 million years ago and also influenced our evolution. “It could be a significant genetic mutation, but we believe it is not the only genetic mutation,” he said. Some monkeys can even use their tails to catch things.

Related: Whose tail runs the internet.

The remaining genetic mutations

Scientists already knew how the ancestry of humans disappeared millions of years ago, but the reasons for how this genetic mutation persisted into our time are still unclear. For Bo Xia and Aitai Enai, this is a question that, at least for the time being, does not have an answer. “Genetic changes happen all the time,” says Enai. And some genetic changes can be positive, some negative, and Shia says it depends on the environment. Usually, if a genetic mutation is negative, the body becomes ill or dies, and thus the genetic mutation cannot be passed on.

But if a genetic mutation is beneficial, it can be passed on from generation to generation. Shia means that the demise of the tail would have brought immense evolutionary benefits to the humanids, which is why it has come so far in time. They may not be able to maintain balance on the trees, but they may be able to move around on two legs and have the ability to use things with their hands. But that does not mean that we have only benefited from the demise. Shia and her team found in experiments on mice that spinal problems are similar to neural tube defects affecting one in 1,000 humans. This defect causes a condition called spina bifida, in which the baby’s spinal cord does not develop fully in the mother’s womb, which can lead to nerve damage and even complete disability.

The genetic mutations that have caused human extinction have been passed down from generation to generation “So I wouldn’t say that genetic mutations are good or bad,” says Shia. That’s enough. ‘ “I think it’s very important,” he says. You just have to look at the genome and I hope it will be a significant addition. ” Enai believes that through this study we can learn more about events in our biological past through the genome. He says: ‘I think this has given us a message to use our computer programs in different ways. We have known about the genome for many years, but what Bo has found now would have been found many years ago. So this work will definitely be inspiring for the scientific community.