There are a lot of versions about the origin of the world. Perhaps one of the most reliable was put forward by the scientist Darwin in his famous works. He relied on existing evidence of evolution, which after him was investigated and confirmed many times. The facts that speak of the consistent development of the organic world are quite convincing and diverse. They prove that all life on Earth arises from pre-existing species as a result of hereditary changes.
Very well, the evolution of animals, as well as some plants, is recorded in fossil remains, which serve as one of the confirmations of how everything developed. In addition, such a "fossil record" allows you to restore individual details of phylogenesis. These residues are not only the teeth, bones, or other hard parts of plants or animals that have been preserved, they are also any traces or prints left by pre-existing organisms. I must say that at present only a small part of what forms of life existed on the planet before is discovered. Paleontologists, scientists involved in the collection and interpretation of data on ancient organisms continue to research and observe this.
It must be said that evidence of the evolution of wildlife is divided into several groups. So, there is evidence that is based on the unity of origin of the organic world. This includes the fact that almost all organisms have a similar elementary chemical composition. Proteins and nucleic acids, which are always constructed from similar components, are very important in vital phenomena in animals, bacteria, and plants. Almost all organisms have a cellular structure . ATP is used as energy storage molecules.
Domestic and foreign scientists have found evidence of evolution that is embryological in nature. As a result of in-depth study in multicellular animals in their infancy, significant similarities are observed. Particularly distinct signs are observed in embryos belonging to the same class or type. So, in terrestrial vertebrates, the laying of gill arches is noted in the same way as in fish, although in adults they do not have a functional value. This suggests that all living organisms have a unity of origin. The manifestations of evolution include human rudiments, that is, undeveloped parts or organs of the body. The most common of them include the coccyx, which is a triangular bone formed from several fused vertebrae. Once it formed a tail, however, with the transition to upright posture, the need for it disappeared. As a result, this organ in humans is in its infancy, however, its presence confirms the theory of evolution.
Atavism should also be noted. By it is meant the appearance of a certain trait that is characteristic of ancestors, but normally it should not be present in modern man. For example, it can be strong hairiness, the presence of more than one pair of mammary glands, etc.
Morphological evidence of evolution is also noted. Among them, forms that combine the attributes of large systematic units are of particular value. In addition, scientists drew attention to the fact that the structure of the forelimbs is fundamentally similar in some vertebrates, despite the fact that they perform different functions.
Rich scientific material for the study of evolution provides a comparison of the animal world of various natural zones. The distribution of various species and types on the planet and their further grouping by geographical conditions clearly reflects the process of historical development of all living things.