1. When “Apollo 11” landed on the moon, if our feet had never evolved, could Neil Armstrong complete this “huge leap”? Our feet make this one of the most impressive feats possible.
2. The evolution of the feet has gone through a long period of time. In the evolution of life, it is generally believed that the first to reach the land from the ocean is the total fins, and the roots of the fins have stalk-shaped feet (limbs) formed. Later, they evolved into salamander amphibians. Although the limbs showed the original shape of the feet, they could only play a supporting role. When moving, they mainly rely on the bending of their bodies to move forward.
3. After the emergence of reptiles, they gradually formed real limbs and were able to run freely on land. It wasn’t until 20 million years ago that great apes evolved into adults, from animals that walk on all fours to people who can walk upright.
4. In the process of the great apes evolving into adults, that is, in the process of evolving from animals that walk on all fours to people who can walk upright, in order to support weight and walk, the feet lose the functions of grasping, pinching, lifting, and pushing, and become the present form. Interestingly, the formation process of the baby’s feet in the mother’s body is like a condensed evolutionary process of the feet.
5. Human feet have large calcaneus, short toes and long and stiff arches. This is a distinguishing feature of our humans because we can effectively use two feet to walk. We humans are the only animals that walk on two legs. Being a biped makes humans great long-distance walkers and runners, while freeing our upper limbs to make and use tools, including weapons. For better or worse, this is a huge leap forward.
6. At least 1.6 million years ago, the ancestors of complete bipeds such as Homo erectus have left Africa, crossed the old world, and reached East Asia, but researchers are still not sure when our peculiar feet evolved .
7.3.2 million years ago, “Australopithecus Lucy” seemed to be a complete biped. However, in 2018, paleoanthropologists discovered that juvenile foot fossils of the same species are closer to those of climbing apes.
8. Of course, the feet can be traced back to earlier evolutionary periods. Different and unrelated organisms have very similar developmental genetic pathways in their species-specific limbs. From wombats to wasps, from humans to halibut, these gene groups are almost universally distributed in animals, indicating that they originated from a common ancestor more than 500 million years ago.
9. However, the first pair of “feet” may belong to mollusks. They have been around for about 540 million years. At that time, the lower abdominal muscles of many species were well developed, allowing them to move through contractions. The tentacles of the squid and the arms of the octopus are evolved from these muscular “feet”.
The large calcaneus, stiff arch and short toes of our feet can effectively help humans walk upright.
10. The feet of terrestrial vertebrates are much more even. We all inherit the same basic foot bones from the earliest four-legged vertebrates or quadrupeds, which left the ocean and came to land 350 million years ago.
11. With the evolution of different foot postures, the shapes and positions of these bones will diversify, sometimes dramatic, such as walking animals (the whole foot is on the ground, like humans and mice), toe animals ( Only the toes are on the ground, like cats and dogs) and hoofed animals (hoofed toes are on the ground, like horses and giraffes).
12. Other primates, such as chimpanzees, have rough feet. In contrast, people think that our toes are too weird. They are short and thick and useless. Why do toes that are similar to fingers are short and slightly “ugly” compared to fingers?
13. Research shows that our feet have been so rough in the past. Our ancestor, Australopithecus, lived 3.5 million years ago and had a pair of feet like chimpanzees. The feet of capable people 1.7 million years ago are very similar to our feet today. Just replace all of our corresponding toes with shorter toes and add an arch to our feet. What happened in this?
14. To make a long story short, our ancestors got down from the tree and started walking on land. When our feet have evolved enough to support us walking on land, we begin to move faster and faster, and eventually learn to run. These changes have forced our feet to evolve a more efficient way to solve balance and power problems.
15. Basically, our feet have become more elastic and more shock-absorbing. In other words, these toes are produced by running. Researchers found that individuals with long toes performed more mechanical work to stabilize their joints and ligaments. This means that they need more energy to run as far as short toes. Our ancestors were really good at long-distance running to chase prey and consume the power of prey.
16. In this hunting mode, people with long toes are naturally eliminated because they need to spend more energy to chase the same prey. Researchers also found that people with short toes may be able to reduce the risk of injury. This means that people with long toes have to spend more energy running the same distance and are very likely to get injured on the way. So our short and thick toes may have evolved to help us run and maintain balance.
17. Scientists have been studying how the feet work. Stress fractures of the lower leg are a common running injury, usually attributed to impact on the road. However, a study published in the Public Library of Science in January this year showed that the real culprit of the fracture is not the strength of the runner’s foot landing, but the pressure on the calf bone caused by muscle contraction.
18. Many insects, spiders, lizards and amphibians use vertical and inverted planes to complete movement and even acrobatic movements, thanks to their various adaptability to the feet.
19. For example, the bottom of a gecko’s toe is covered with super-flexible tiny hairs that grow at oblique or non-vertical angles. The tiny scales of hair create electromagnetic attraction to the wall or ceiling surface, but their angle and flexibility allow the gecko to loosen its feet easily when moving.
20. Other anti-gravity animals, including many invertebrates, usually have wet feet. Scientists believe this helps them attach to a flat surface. But a study on Mythimna separata found that the secretion of fluid from the foot pads has nothing to do with adhesion. On the contrary, the liquid seems to act as a lubricant, helping insects loose their feet when they move on the surface. This discovery may have important implications for robot design.