One of the most famous and most studied ofpaleontological evidence of evolution is a phylogenetic series of modern single-footed ungulates. Multiple paleontological finds and identified transitional forms create the scientific evidence base of this series. The phylogenetic series of the horse described by the Russian biologist Vladimir Onufrievich Kovalevsky as early as 1873 still remains the “icon” of evolutionary paleontology.
Evolution through the ages
In evolution, phylogenetic ranks aresuccessively alternating transitional forms, which led to the formation of modern species. In terms of the number of links, the series can be full or partial, but the presence of successive transitional forms is an indispensable condition for their description.
The phylogenetic range of the horse belongs toevidence of evolution is due to the presence of such successive forms, replacing each other. The multiplicity of paleontological finds gives it a high degree of reliability.
Examples of phylogenetic series
A number of horses are not the only ones described.examples. The phylogenetic range of whales and birds is well studied and has a high degree of accuracy. And the phylogenetic range of modern chimpanzees and humans is controversial in scientific circles and most used in various populist insinuations. Disputes about the missing links here do not subside in the scientific community. But no matter how many points of view, the significance of phylogenetic series as evidence of the evolutionary adaptability of organisms to changing environmental conditions remains indisputable.
Relationship between the evolution of horses and the environment
Multiple studies of paleontologistsconfirmed the theory of O. V. Kovalevsky about the close relationship of changes in the skeleton of the ancestors of horses with environmental changes. The changing climate led to a decrease in forest areas, and the ancestors of modern single-footed ungulates adapted to the conditions of life in the steppes. The need for rapid movement provoked modifications to the structure and number of fingers on the limbs, changes in the skeleton and teeth.
The first link in the chain
In the early Eocene, more than 65 million years ago,He lived the first great-grandmother of the modern horse This “low horse” or Eohippus, which was about the size of a dog (up to 30 cm), rested on the entire foot of the limb, which had four (front) and three (back) fingers with small hooves. Ate eogippus shoots and leaves and had lumpy teeth. Damned coloring and sparse hair on a rolling tail - such is the distant ancestor of horses and zebras on Earth.
Intermediate links
Порядка 25 миллионов лет назад климат на планете changed, and steppe expanses began to come to replace forests. In the Miocene (20 million years ago), the meso-hippus and para-hippus appear, already more similar to modern horses. And the first herbivorous ancestor in the phylogenetic series of the horse is considered to be the Merikhyppus and Pliogippus, which enter the arena of life 2 million years ago. Hipparion - the last three-fingered link
This ancestor lived in the Miocene and Pliocene plains.North America, Asia and Africa. This three-fingered horse, resembling a gazelle, did not yet have hoofs, but could run fast, ate grass, and it was she who occupied vast territories.
Single-footed horse - pliogyppus
These single-tan representatives appear 5million years ago in the same territories as hipparions. The environmental conditions change - they become even drier, and the steppes grow considerably. It was here that the one-tier was the more important sign for survival. These horses were up to 1.2 meters high at the withers, had 19 pairs of ribs and strong leg muscles. Their teeth acquire long crowns and creases of enamel with a developed cement layer.
Familiar horse
Modern horse as a final stagephylogenetic series appeared at the end of the Neogene, and at the end of the last ice age (about 10 thousand years ago) millions of wild horses were already grazing in Europe and Asia. Although the efforts of primitive hunters and the reduction of pastures made the wild horse a rarity already 4 thousand years ago. But its two subspecies — the tarpan in Russia and the Przhevalsky horse in Mongolia — managed to hold out much longer than the rest.
Wild horses
Today, these wild horses are practically notleft. The Russian tarpan is considered an extinct species, and the Przhevalsky horse is not found in natural conditions. Herds of horses that graze freely are wild, domesticated forms. Such horses, though quickly returning to wild life, are still different from true wild horses.
They have long manes and tails, and they are unsuited. Exclusively Prjanesky's buck and equine tarpans have, as it were, trimmed bangs, manes and tails.
In Central and North America, wild horsesThey were completely exterminated by the Indians and appeared there only after the arrival of Europeans in the 15th century. The feral descendants of the horses of the conquistadors gave rise to numerous herds of mustangs, whose numbers today are controlled by shooting.
In addition to mustangs in North America, there are two kindswild island ponies - on the islands of Assatig and Sable. The semi-wild herds of Camargue horses are found in the south of France. In the mountains and marshes of Britain, you can also find some wild ponies.
Our favorite racers
The man tamed the horse and brought out more than 300 of her.rocks. From heavyweights to miniature ponies and handsome race breeds. About 50 horse breeds are bred in Russia. The most famous of them - Oryol trotter. Exceptionally white color, excellent lynx and agility - these qualities were so appreciated by Count Orlov, who is considered the founder of this breed.
