Explain the bisexual phenomenon of animals

In the natural world, there are countless animals that carry both sexes that scientists are trying to explain.

Learn about bisexual animals in the world

The left and right half of the hermaphrodite chicken.(Photo: Michael Clinton).

Seen from the right, Dr. HE Schaef's chicken is no different from a young rooster with bright red bibs and crest. But looking from the left, it is like a hen with a smaller body and the features on me are also less colorful. She kicked the roof and laid her eggs.

When the animal dies, Schaef decides to slaughter it. After cleaning chicken feathers, he found that the right half of the bone was bigger than the left half. When pecking at the chicken to peck, he found a testicle and an ovary with a newly formed egg.

Schaef retains the skeleton and gives it to her grandmother, the surgeon Madge Thurlow Macklin. The story was rewritten and published in Experimental Zoology in 1923.

Shrimp hermaphrodite.(Photo: Richard Palmer).

Almost a century after Schaef's strange meal, many cases of other bisexual animals were discovered.

The lobster with its bizarre body, the two halves of these two sex-specific traits was donated to the British Royal Society by New Fish from Newgate on May 7, 1975.

Kentish glory moths (Endromis versicolora) are bisexual: the left half is female, the right half is male.(Photo: FLPA).

The list of bisexual animals also includes crabs, silkworms, butterflies, bees, snakes and birds. It is difficult to say exactly how common bisexual individuals are in nature. However, Michael Clinton, Edinburgh University, England, estimates there are about 1 / 1,000.00-1 / 10,000 individual birds on this list. No one has determined the proportion of bisexual individuals in mammals.

The northern hostage is bisexual, with half the red glowing male, the half gray.(Photo: Brian Peer).

Researchers believe that the bird never sang and the hermaphrodites like this either silently alienated, or were violently attacked by individuals of the same species.

There is a theory that this strange phenomenon is caused by mutations of genes after fertilization . Biologic genes are determined by the combination of sex chromosomes (chromosomes). In humans, men carry an X chromosome and a Y chromosome, while females carry two X chromosomes. But in animals it is different. In chickens, males carry two ZSTs, while females carry one Z chromosome and one W.

A cell can lose one of the two chromosomes and this has a great effect on sex. Suppose that during the development of chicken embryos carrying chromosome pairs of ZW, cells suddenly lose the W chromosome to develop into females. Therefore, it will develop male characteristics.

If that cell is multiplied, its copies will be male. Meanwhile, other cells in the embryo will still be female. As a result, the chicken has the ability to become bisexual.

One of Michael Clinton's bisexual chickens.(Photo: Michael Clinton).

A few years ago, Clinton received a phone call that required him to rethink the hypothesis that bisexual chickens were the result of genetic changes.

One of his colleagues called and informed him that he found a hermaphrodite chicken quite similar to Schaef's chicken on a farm. There, they found two other bisexual chickens with completely identical characteristics.

However, when testing the genes of these chickens, Clinton found that throughout the animal's body were carrying normal sex chromosomes. The second half carries the chromosome pair of ZW and the other half carries the chromosome ZZ. In other words, the chickens are made up of two different halves. The unexpected result made him initially disappointed because the previous hypothesis proved to be wrong.

9 day old chicken embryos.(Photo: Jerome Wexler / SPL).

Clinton proposed another hypothesis that explains the phenomenon of hermaphrodite in birds. When the egg is formed, the cell removes half of the chromosomes contained in a DNA bag called "polarity ." However, in rare cases, both the pole and the nucleus are preserved and continue to grow. At that time, there will be two kernels in the egg, forming two different genders.

Chickens can somehow eliminate an unwanted sex before laying eggs and thus control the chicks' sex. But if it doesn't, a bisexual chicken will be born.

The results of Clinton's research show that sex development in birds and mammals is different. In mammals such as humans, sex is largely determined by blood sex hormones. In birds, gender is controlled by cells.

Amphibian Butterfly.(Photo: Josh Jahner).

Josh Jahner, of the University of Nevada, USA, studied many different colored butterflies on the wings and gave another explanation for the animal hermaphrodite phenomenon. According to him, people can unknowingly make this phenomenon popular.

In April 2015, Jahner reported a strange coincidence. He studied American butterflies called Lycaeides and never witnessed a bisexual individual before the Fukushima Daiichi atomic disaster occurred in Japan in 2011. Within 16 months, he accidentally caught Meet 6 bisexual cases in this butterfly.

Genital part of male butterfly (left), female butterfly (middle) and bisexual butterfly (right).(Photo: Josh Jahner).

Researchers also found many bisexual butterflies after the nuclear disaster in Chernobyl, Ukraine. This suggests that a small amount of radiation may also increase the chances of fertilization of bisexual butterflies.