Confirmation of the theory of evolution, or Atavism, rudiments, homologous and analogous organs

In science, the fundamental concept is consideredunity of the origin of life on Earth. And therefore, the discovery, which is applicable to one form, can be attributed to all the others. Due to this, by the way, the functions of many human internal organs were studied and methods for treating dangerous diseases were developed.

Examples of similar and homologous organs

It is impossible, however, relying on the kinship of allliving on earth, mix homologous and similar organs. The former have the same structure and develop from the same embryonic buds, confirming the unity of origin (for example, the five-fingered limb of different animal species). But similar bodies, often performing the same function in different animals, have different primordia.

A common example of such cases is the wing.In insects and birds, it performs an identical function. But in insects, these are chitinous protrusions on the surface of the back, and in birds, the forelimbs, which have changed in the process of evolution. The same parallel can be drawn between the gills in dragonfly larvae and in fish.

The eyes of humans and octopuses can also be defined as similar organs. Despite the resemblance, they are absolutely

different in structure.The lens of the human eye is fixed, and the eye itself is an outgrowth of the brain germ. While in an octopus, the organs of vision are formations from the integument of the body in which the lens of the lens approaches or moves away from the retina, aiming at the object of attention of the animal in order to establish the correct focus.

Examples of analogy can be considered even among pigments such as hemoglobin and hemocyanin. They carry oxygen in the same way, but their molecular structure has big differences.

Rudiments

Atavisms and rudiments confirm the theory of the origin of life in their own way.

The latter include, as a rule, those bodies thatdo not perform their original function, losing it in the process of evolution. But it is impossible to consider all rudiments absolutely useless. They just often perform less important actions.

For example, ostrich wings can be definedas rudimentary organs, because they do not cope with the main task of the bird's wing, and they are used to attract females and to maintain balance while running. Thus, the complexity of the structure of this body is inadequate to the simplicity of the task it performs. This is a sign of the rudiment.

But the penguin's wing can not be considered as such, since it performs a rather complex function as a fin.

The eyes of the mole and the mole rat, which either do not see anything at all, or only distinguish between darkness and light, can be attributed to the rudiments.

In humans, this characteristic has tail vertebrae, muscles that

they helped our ancestors raise their bristles, and their muscles to move their ears. Everyone knows another human rudiment - the process of the cecum (appendix).

Atavism

When does an individual show signscharacteristic of her distant ancestors - this phenomenon is called atavism. For example, the appearance in some people of solid hair on the body or an additional pair of mammary glands, the caudal process in humans, or the hind fins of a dolphin.

The appearance of atavism can be explained by the presence of genes responsible for this trait in DNA. But they have not been functioning for a long time, since their action has been suppressed by other genes.

Homologous and similar organs, rudiments and atavisms - all this is undoubted confirmation of the unity of the origin of life of creatures inhabiting the Earth.