10 most useless body parts

The wings of the birds do not fly, the hind legs of the whales, the fur on the body, the eyes of the blind fish . These parts are like that, because they seem completely useless.

1. Wings of birds do not fly

In 1798, 60 years before the first book of Charles Darwin was published, a French anatomist, É´ienne Geoffroy St. Hilaire arrived in Egypt with Napoleon where he witnessed and wrote about a bird that didn't fly with seemingly useless wings for flying. The bird he describes is an ostrich, but is called " cassowary ", a term later used to refer to many birds with ostrich-like looks.

Ostrich wings and cassowary birds, New Zealand kiwi birds, and night parrots . are a sign of a useless genus.

In general, bird wings are a complex structure specialized specifically for flights and it is not different between species. Only, in species that run on the ground, these wings do not help them fly, but are used for balance when running and to flirt with their partners in love performances.

2. Back leg bone in whale

Enlarged hind limbs of whales.(Photo: LiveScience)

Biologists believe that the only vertebrate species on earth are creatures that swim underwater, with no arms or legs. At some point, these fish began to grow their hands and feet, and could eventually step out of the water, onto the mainland.

But after evolving here, some animals return to the water, and they are the ancestors of whales today. Although it may seem useless, evolution has left traces of hind legs, and we can still encounter these abundant legs on modern whales.

Traces of hind legs are found on whales, horned whales, humpback whales and in many sperm samples. Most models have only leg bones, but some also have complete toes.

3. Hair on human body

Animals use their fur to keep their bodies warm, and to ruffle them when they meet an enemy. Humans for years evolved to remove the ancestors' thick fur, and put on the warm fur of other animals. And of course, today, some of our body hairs are still useful, for example, eyebrows help prevent sweat from falling into the eyes, and facial hair in men helps to impress women. But in general, all other hairs are useless.

4. Coccyx in humans

This exposed spine is the only trace left of the tail that animals still use to balance, to communicate, and in some primates used as a limb to hold. When our ancestors learned to stand upright, the tail became meaningless, and it slowly disappeared. There are many medical documents that record that when surgery removes the amputated bone, it has no significant effect. People also reported cases of babies born with oversized long tail bones, but did not cause any health effects.

5. Blind eye of fish Astyanax Mexicanus

In an experiment designed by nature, a fish called Astyanax mexicanus, living in deep caves off the coast of Mexico, saw nothing. This fish also has eyes, but as soon as it grows in eggs, its eyes have begun to degenerate, and the animal is born with remnants of the eye covered with a layer of skin.

This degenerate eye may have formed after hundreds or even thousands of years living in complete darkness. As with an experiment, control is necessary, and fortunately, fish of the same species live just above them, near the surface of the water, where there is a lot of light, there are active eyes often.

To check if the eyes of blind fish can be operated if they are created with a suitable environment, the scientists removed the lens from the eyes of the fish swimming near the water surface and implanted it into the eyes of the blind fish . Within 8 days, the eyes began to appear under the skin, and after two months, they looked back.

6. Wisdom teeth

With so much pain, time and money poured into the wisdom tooth, people became tired of the vestiges of the great jaws of their ancestors. But despite our disdain, wisdom teeth still exist.

There are two possible reasons why wisdom teeth have become "ruins". The first is that the human jaws become smaller than their ancestors, and the wisdom teeth must try to rise in the much smaller jaws.

The second reason is that there is much to do with oral hygiene. A few thousand years ago, it was normal for an 18-year-old man to lose most, even his teeth, and wisdom teeth became useful. Now, people brush their teeth twice a day, and teeth can follow them all their lives.

7. Reproductive organ of dandelion

Dandelion, like all other flowers, has stamens and buds suitable for reproduction, but not used. Dandelions reproduce without fertilization, they replicate themselves, and are quite successful in that.

8. Sex fake in Whiptail virgin lizard

In some species of lizards in the genus Cnemidophorus, only females exist, which seems to be a problem if they want to maintain the race. However, the girls do not need males, they reproduce in a simple way - that is, an unfertilized egg grows into a new individual. Although mating seems unnecessary and useless, lizards still try to 'love', and often one of the females will start acting like a male, seeking to mate with another female.

This behavior can be considered an imperfect form, falling from their ancestors' mating instincts.

9. Men's breast tissue and nipples

Men's nipple theme is quite sensitive to many people. Those who want to eliminate evolution theory can ask this question: Are men descendants of women?

The answer is no. Both men and women have nipples because in the early stages of embryonic development, an unborn child is actually asexual. Nipples were present in both male and female embryos; Only to the later stages of the fetus, the testosterone promotes the formation of different sex characteristics.

In all mammals, males and females have mammary glands. Men 's nipples are an ancient form of vestige, which may have a small role in sexual stimulation and a small number of men can also produce milk. However, they are not fully functional and tumors can grow in breast tissue in both sexes.

10. Human appendages

In herbivorous vertebrates, the appendix is ​​much larger and it retains its function to help digest food. The human intestine is a piece that attaches to the small intestine to meet and does not directly support digestion. Biologists believe that it is a remnant from grass-eating ancestors.

T. An