If you think about it a little, the vast majority of mammals have tails.
For example, we are familiar with cats and dogs:
Supposedly, we humans are also primates, so why don't we have tails? Let's take a look!
It turns out that when we humans were not fully evolved, we also had a tail of our own, but at a certain stage of evolution, we were cut by nature!
If you observe the growth of the fetus, you will find that when it is still an embryo, especially in the 31-35 days or so, the existence of the tail can be clearly seen, but after continuous development, the tail gradually disappears and becomes a tail vertebra caused by 3-5 bone fused.
In fact, it is useless to think that we humans have this tail.
Some animals grow tails because they maintain their own balance in daily life, while humans have inner ear vestibular balance organs, and the coordination of the cerebellum can easily grasp the balance.
Some animals have tails to store fat for hibernation and provide their own food and clothing, while humans have hands and feet and intelligent brains, and they do not need to consider storing fat for the winter, so they do not need tails to provide additional blessings.
Reviewed by Dr. Ning Tao, Associate Professor, Institute of Biophysics, Chinese Academy of Sciences