A popular story about the platypus states that supposedly this animal has simultaneously possesses as many as three classes of vertebrates: reptiles, birds and mammals. We decided to check if such a statement is correct from the point of view of science.

Media They sayLike "biologists found outthat the platypus has genes of birds, reptiles and mammals at the same time. ” Such the same information Can Meet on different entertainment sites, in collections Entertaining facts, c social networks, Blogs And Internet quiz. Reptile genes like They say The authors of such publications are responsible for the plaintos for the fact that "females lay eggs, and males produce poison." Bird genes supposedly do For plasticos, “electroreception is possible - it allows them to look for prey in orb, muddy reservoirs. Such receptors that can capture electricity in the environment are located at the beast at the edges of the beak (which is very similar to the location of the "compass" in many migratory birds). " In addition, on the Internet Turn Attention to the fact that “these mammals are owners of vitellogenin-gen, which can usually be found in birds and reptiles. It is this gene that is responsible for the production of protein in an egg, which feeds on the embarrass of the platypus. ”

Contrary to a common representation, genes do not describe the state of the body and its attitude to one or another class of animals (for example, there is no such gene that would mean “to be a bird”). Rather, they are responsible for some characteristic processes or skills (for example, to be able to produce milk to feed cubs or, conversely, be able to lay eggs). Therefore, the wording of “having a bird gene” or “having a reptile gene” is generally not very correct. So, genetically man and chicken identical About 60%, which does not mean that a person has bird genes.

The plaintos was completely genome Deciphered in 2021, but partial decoding Published Since 2004. The attention of scientists this animal attracts the features of the structure of its body. In the description of the above -mentioned study of 2021, which is referred to in many tested publications, the platypus genome was compared, in particular, with the human genome, malicious, mouse, opossum, chicken and green lizards. In the conclusions of the article, there was no formulation that the platypus had genes of birds and reptiles - scientists only clarified how evolution was on the example of the acquisition or loss of certain genes.

Together with the sessiles, the platypus belongs to the unit of one -pass. Its name describes peculiarity Representatives of the species included in the detachment - the intestines, the excretory and sexual systems in them open into a single cloak, which is related to them with amphibians, reptiles, birds and some species of fish (sharks, slopes and two -skinned ones).

In addition, platypus He lays eggs, but feeds the cubs with milk, does not have a teeth in adulthood (instead grinds food with horny plates), produces poison and senses prey with electrical signals. It was the possession of such unusual characteristics, most likely, that led to the fact that statements appeared in the media, supposedly the platypus has genes of other classes of mammals.

The platypus is really possesses one functional (VTG2) and one partial (VTG1) copy of the gene responsible for the production of glycolipoprotein Vitellogeninwho, in turn, plays an important role in the formation of the yolk of the egg. Reptiles and birds, for example, have three copies of the VTG gene and can lay eggs, and in honey bees vitellogenin and completely answers For the distribution of labor and social ties. However, the presence of such a gene does not yet make it possible to say that the creature has the genes of a bird, insect or reptile; Man also has partial sequence of this gene, like some other mammals (for example, Opossumes).

However, due to the fact that the platypes have an incomplete set of these genes, to provide the yolk of the egg with the necessary nutrients for the entire period of development of the cub they Can't. Unlike birds, the eggs of the platypus are more time inside the mother's body than outside it - for about a month the platypus wears eggs and only for 10 days they hatch them.

At the same time, Mark Scientists sequenced by the genome, the platypes have a genome that encodes milk proteins secreted during lactation. In addition to three copies characteristic of all mammals, the plaintos have two more additional ones: CSN2 and CSN3, whose functions are still unknown to scientists. And although the mammary glands of the female platypus There are, they have no nipples - milk flows onto the mother’s stomach through expanded pores.

The presence of a beak, like the absence of teeth, also does not make a living creature automatically a bird. Some mammals, whose belonging to this class is not disputed, also have no teeth - for example, Muravids And Pangolins. The beak of the platypus Not similar bird - it is stretched between the preliminary bone and the lower jaw and Represents It is not a solid formation, but soft and leathery, on the surface of which there are thousands of receptors that allow you to detect prey. The presence of electroreception is also inherent and other mammals - the Guyan Dolphin and Echidna.

The ability to produce poison is most common in reptiles, arthropods, insects and fish, but nevertheless it is also found in mammals. So, some species are poisonous Wasteen, slit, vampire bats And even one type of primates is thick (it is slow) Lori.

However, the poison of the platypus Includes Defenzins (mammalian proteins for the destruction of bacteria and viruses) and a hormone called glucagonopian peptide-1 (GLP-1), which are also characteristic of mammals, rather than insects, spiders or snakes.

This is not limited to the list of amazing features of the plaintos. How found out Scientists, he has ten sex chromosomes instead of two mammals of two for mammals: XXXXXXXXXX in a female and XYXYXYXYXY in a male, which are connected in the ring structure. No other mammal (as well as birds or reptiles) has such a structure, it is found only in some invertebrates and plants. However, on the basis of this fact, it never occurred to anyone to write news that the platypes, it turns out, have plant genes.

Thus, the platypus is indeed an extremely unusual representative of mammals, but the journalists unnecessarily voluntarily interpreted the results of the work of scientists sequenced by the genome. They only indicated that the animal has some genes that fully function among representatives of other classes, which only confirms the theory of evolution of Darwin species, but does not mean that the plasticos were directly inherited by birds or reptiles. Moreover, in a reduced state, some of the mentioned genes even have a person, which, however, is not equivalent to what a person has, for example, reptile genes.

Image on the cover: Australian Geographic