Evolution: Why females live longer | Science| In-depth reporting on science and technology – DW (English)

On average, women live six to eight years longer than men. At least if they are treated well. But we have known that for quite some time.

What we didn't know until now is that the same is true for many wild animals. This is the conclusion reached by an international team of researchers, including Biologists from the University of Bath, who investigated the lifespans of 101 different animal species. The studywas published in the Proceedings of the National Academy of Sciences.

In the animal kingdom, the difference in life expectancy among males and females is even greater than in humans. For 60% of the animal species studied, females live on average 18% longer than their male conspecifics. The difference between men and women is nearly 8%.

According to the World Health Organization (WHO),this is because women have a biological advantage over men when it comes to health and thus life expectancy.

X-chromosome, estrogen and premature death

Women have two X chromosomes, while men have only one (they have a Y chromosome instead).

On the X chromosomes some immune-relevant genes are encoded. Among them are genes that recognise certain pathogens and can thus set the corresponding immune response in motion. The hormone estrogen, which women naturally have more of than men, also has a protective function.

Scientists suspect that biology holds its protective hand in a very similar way over the female animal world.

No risk, no fun, he said

These biological advantages might seem like blatant injustice, but they are not the only reason why women live longer. According to the WHO, this is also due to the fact that women tend to be less willing to take risks.

In other words, women generally smoke and drink less and come up with stupid ideas less often. As I said less often.

Read more:Psychology: A happy partner is the elixir of longer life

Although the shorter lifespan of male animals cannot be explained by excessive tobacco and alcohol consumption, scientists suspect sex-specific behavior as one of the reasons.

The researchers found that female lions live at least twice as long as males. "Female lions live together in a pack in which sisters, mothers and daughters hunt together and care for each other. Adult male lions, on the other hand, often live alone or with their brothers and therefore do not have the same support network," says one of the study's authors, Tams Szkely from the Milner Centre for Evolution at the University of Bath.

Longer life behind bars?

The researchers also suspect that it is beneficial to female longevity if the male shows himself to be the most committed father possible. This could make up for the health costs associated with birth and raising the offspring.

Since much is still speculation, more data is needed to establish the real reasons for the difference in life expectancy.

The next step will be to examine the lifespans of animals living in captivity in order to compare it with that of their wild counterparts.

It remains to be seen whether all-inclusive care means that zoo animals live longer or whether the boredom of captivity is more likely to make them depressed and kill them prematurely.

Read more:Insects are dying and nobody knows how fast

The sword-billed hummingbirds beak is longer than its body. It has the longest beak of all known hummingbird species. And it needs it! One of the bird's main sources of food is nectar, which it drinks from very long, slender hanging flower crowns. With its beak wide open, it can also catch insects.

Two star-like shapes on its snout make the star-nosed mole a very well-equipped hunter. The appendages around its nostrils a total of 22 fleshy tentacles are sensory organs. With these it can examine 13 potential prey animals per second. We can't even look that fast!

An egg-laying mammal with a beavers tail and a ducks beak. What sounds like a fantasy creature actually exists in Australia. The platypus boasts a large, flexible beak with a leather-like surface. A built-in snorkel is also included: its nostrils are on top. This allows the animal to dive underwater and breathe at the same time.

Don't worry, as scary as it may appear, this vampire is vegetarian. The tufted deer prefers to graze at dusk. If it senses danger, it does something unusual: it barks. Deer do this to warn each other. While fleeing, they erect their white tail an escape-signal among tufted deer.

This bird may look like a character from a comic, but the shoebill actually walks among us in the swamps of central tropical Africa. It often stands motionless in the water and looks downward. When it detects prey, it strikes at lightning speed. With the hook at the top of its beak, it grabs its prey. Even large lungfishes are swallowed up whole.

With a body length of up to 10 meters, the basking shark is the second-largest fish in the world, after the whale shark. Despite its monstrous size, it's anything but bloodthirsty; basking sharks eat just one thing: plankton. They swim with their mouths wide open to catch and filter food. Water that enters its mouth with the plankton is filtered out through its gills 1800 tons of water per hour.

Gavials live in Southeast Asia. In contrast to the crocodile, gavials don't eat zebras or deer, but fish. Its snout is therefore long, narrow and home to very many teeth. Perfect for catching fish!

The sucking trunk of the hummingbird hawk-moth is not only very long, it's also extremely precise. The butterfly can suck nectar from up to 100 flowers per minute. While doing so, the moth hovers in front of the flower. With its long trunk, the hummingbird hawk-moth can also reach the nectar of flowers with particularly long calyxes out of reach for others.

The spoonbill is equipped with the perfect tool. No matter fish, frog or other water-dweller, nothing escapes this beak. In searching for food. the spoonbill usually goes into shallow water. However, sometimes it also wanders the coast. In the mud flats, it swings its head back and forth, filtering food from the shallow water.

Dugongs feed on seaweed. They prefer the part of the plants that lay underground. And they have developed a special technique for this: this manatee can dig. It digs out the plant with its upper lip, then the roots are pulled out of the ground. It shakes off the dirt and then sucks the plant into its mouth.

Author: Liyang Zhao

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Evolution: Why females live longer | Science| In-depth reporting on science and technology - DW (English)

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