Collections of mammoth fauna in the Geological Museum of Ighabm from wounds. Fossil mammals Mammoth fauna lifetime
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Age of Mammoths
In the Upper Pleistocene, a complex developed in Northern Eurasia mammal fauna, called the mammoth fauna, or mammoth complex. It is the mammoth that is one of the main elements of this animal community, which also included musk oxen, woolly rhinoceroses, bison, reindeer, saigas, arctic foxes, wolves, etc.
Fauna large mammals, who lived 70-10 thousand on the territory of Siberia, was very diverse. The mammoth was its main component, since the bones of these elephants are found in almost all locations in Siberia. Because of this, it received the name “mammoth fauna” of the late Pleistocene (Pleistocene is geological period, which began 1.85 million years ago and ended 10 thousand years ago). In addition to the mammoth, it includes 19 more species (some of them are listed below in order of frequency of occurrence in Siberia): ancient horse (2 or 3 species), ancient bison, reindeer, giant deer, red deer, saiga antelope, woolly rhinoceros, moose, cave bear, cave lion. Some of these animals have become extinct, but most live in Eurasia now, but not at all where they used to be, in other climatic zones, and these species no longer form communities together as before. Reindeer lives in the tundra and taiga, and horses are found (used to be found, wild horses no longer left) in the steppe and forest-steppe zones. This change in animal ranges clearly shows us what enormous changes have occurred in the world over the past thousands of years.
Woolly rhinoceros and megafauna
During the Ice Age, Siberia was inhabited by very unusual species animals. Many of them are no longer on Earth. The largest of them was the mammoth. Paleontologists unite all animals that lived simultaneously with the mammoth into the mammoth faunal complex (“mammoth fauna”).
A significant part of these animals died out at the end of the Pleistocene - beginning of the Holocene (about 10 thousand years ago), unable to get used to the new natural and climatic conditions. Of the large extinct species, the mammoth fauna includes: mammoth, woolly rhinoceros, big-horned deer, primitive bison, primitive horse, cave lion, cave bear, cave hyena, primitive aurochs.
But many representatives of the animal world of the mammoth era were able to adapt to climate warming and habitat changes in the Holocene. They survived and still live on Earth. Some had to move to more northern areas for this. For example, reindeer, arctic foxes and lemings now live only in the tundra. Others, such as saigas and camels, moved south into the dry steppes. Yaks and musk oxen have climbed into the snowy highlands and now live only in a very limited area. Elks, wolves and wolverines have perfectly adapted to life in the forest zone.
All these animals are very different, they differ in size, appearance, way of life. They belong to different species groups. But they have one significant similarity - their adaptability to life in the harsh climate of the Ice Age. At this time, most of them acquired a warm fur coat - reliable protection from frost and wind. Many animal species have increased in size. Large body weight and fat subcutaneous fat helped them endure the harsh climate more easily.
Hundreds of thousands of years is a huge period of time; during this time, a wide variety of changes took place in nature, the glacier advanced and retreated, and natural zones moved after it. Animal settlement territories decreased and expanded. The animals themselves also changed, some species disappeared and were replaced by others. Scientists believe that even in short periods During warming periods, the sizes of many species decreased, and during cold periods they increased. Large animals tolerate cold more easily, but they need to eat more. And during the last warming in the Holocene era, forests replaced the tundra and steppes, shrub and grass vegetation decreased, feed base herbivores have greatly decreased. Therefore, the largest animals of the mammoth complex became extinct.
Woolly rhinoceroses lived happily before the Neanderthals
The ancestors of woolly rhinoceroses arose about 2 million years ago in the northern foothills of the Himalayas. For hundreds of thousands of years they lived in central China and east of Lake Baikal.
Much later, woolly rhinoceroses arrived from Asia to central Europe. Some fossil remains found in Germany are about 460 thousand years old, so woolly rhinoceroses lived here long before Neanderthals appeared in Europe. This was proven by employees of the Frankfurt Senckenberg Research Institute, who managed to piece together 50 pieces of the skull of the woolly rhinoceros Coelodonta tologoijensis.
Woolly rhinoceroses kept their heads close to the ground while feeding and, with their powerful teeth, vaguely resembled a modern working lawn mower. The woolly rhinoceros weighed about 1.7 tons and had long fur and a warm undercoat. On his head, near his nose, he had two horns, one large, the other smaller. The size of a large one could exceed 1 m in length.
Contemporaries of the found woolly rhinoceros adapted to living conditions near the glacier. While other animals fled from the north of Europe to warmer southern regions, furry giants, like mammoths, happily grazed on the frozen treeless plains. This is what Germany looked like half a million years ago.
European woolly rhinoceroses also lived before, the remains of which were found in the dinners of ancient Neanderthals. It is reliably known that hominids hunted these animals 70 thousand years ago, and 30 thousand years ago ancient people depicted two-horned animals in cave paintings in Southern France. Although scientists call one of the reasons for the extinction of woolly rhinoceroses anthropogenic factor However, climate change and the onset of heat about 8 thousand years ago led to the fact that they were unable to adapt to the rapidly changing environment and vegetation in particular, as a result of which they died out.
Berezovsky mammoth. Reconstruction of a mammoth found in 1926 in Siberia. Zoological Museum. Petersburg.
MAMMOTH FAUNA -mammoth, musk ox, cave bear, deer, woolly rhinoceros and other animals that lived during the late glaciation (Pleistocene). When mammoths died out, in the south. a productive economy appeared. For example, monuments with the earliest elements of a productive economy of the Zarzi B type are dated 12000+400, Khotu - from 11860+80 to 9190±590, Belt - 11489±550, Jarmo - 11240+300, etc. Mammoths: Kunda (tusks) - 9780+260, Berelekh (fabric) - 10370+90, Kostenki (bone) - 11000+200, Yudinovka (bone) - 13650+200, 138300+850, Eliseevich (bone) -14470+180, 15600+200 thousand years ago. Apparently, the reasons that caused the death of the mammoths and the emergence of a new type of economy acted simultaneously, and they are associated with a sharp change in natural conditions, which also caused the melting of the glacier.
At the end of the Ice Age, huge herds of animals grazed in Europe - p. deer, bison, horses (the Irish deer had horns up to 4m wide). The glaciers are gone and the grass has become smaller. Mammoths and other large herbivores went for grass on the village. They climbed to Taimyr and Chukotka, but everywhere, instead of the fertile steppes and forest-steppes of the periglacial region, they were met by the waters of the Arctic Ocean... Large animals were doomed to death. Some of the hardiest specimens tried to adapt to the new conditions, but they too died. One of the last juveniles froze to death on Taimyr 11,450 years ago. Reindeer managed to adapt to the conditions of the polar tundra, where they still live. There is less food for humans. At European sites, rhinoceros bones are disappearing and the number of bones of hare, arctic fox and other small animals is increasing. Mammoth carcasses in their entirety have been found more than once in the permafrost layer on the village. Siberia. These carcasses were so well preserved that the dogs (and, as Solzhenitsyn says, the prisoners) ate the mammoth meat with pleasure. In 1910, the remains of one of these mammoths were brought by an expedition of the Academy of Sciences. A thick layer of subcutaneous fat and thick fur protected the mammoth from the polar cold. The mammoth's stomach was filled with the remains of sedge, pungent buttercup and other types of polar grasses and small shrubs. Of the modern elephants, the mammoth is closest to the Indian elephant. But the mammoth is more clumsy, its head is more massive, it has a steep hump above its front shoulder blades and huge tusks (incisors), often with spirally curved ends. The length of a tusk was sometimes more than 4 m, and the weight of a pair of tusks was approx. 300 kg. The mammoth's body was completely covered with thick hair of black-brown or reddish-brown color, especially lush on the sides. A mane of thick, long red hair hung from his shoulders and chest. The skin removed from the animal took 30 m 2 . The weight of mammoth bones (without tusks) was 1500 kg. The weight of the mammoth itself reached 5 tons. Mammoths were perfectly adapted to the conditions of the Arctic nature of that time. In the water meadows they found abundant food in the form of lush green grass. According to scientists, one mammoth consumed up to 100 kg of plant food per day. In winter, mammoths could get food from under the snow, raking it with their tusks. Interestingly, the end of the mammoth's trunk was designed differently from that of an elephant. It had two palm-shaped protrusions for gripping low polar grass. The lifespan of mammoths is now determined quite accurately using C-14. In Berelekh on Indigirka, where a whole cemetery of mammoths was found, they died between 11830±±110 and 12240±160 years ago. The most ancient mammoths date back to ca. 50 thousand years ago.
A contemporary of the mammoth and its “eternal companion” was the hairy, or woolly, rhinoceros. On its muzzle grew a curved flat horn approx. 1 m. The second horn grew on the forehead.
There is still debate about what the third member of this community of fossil animals looked like. At first it was called the "cave lion". But this name is not accurate enough, since this huge cat combined the characteristics of both a lion and a tiger in the structure of its body. She possessed all the qualities of these predators, which made her a true scourge of all living things: the fury and strength of a lion, the agility, cunning and bloodthirstiness of a tiger. This was the true king of beasts of that time, the ruler of the disappeared animal world ice age.
Next to mammoths and rhinoceroses in the steppes and tundras, not only herds of s. deer, but also herds of wild horses and wild bulls. Along with them, in a bizarre mixture, there were animals of the deep Arctic and Central Asian deserts, mountain areas and steppe spaces: arctic fox and saiga antelope, snow leopard and red deer.
At the same time, in relative proximity to the boundaries of glaciation in Eurasia and North America, a specific periglacial belt was formed with special physical and geographical conditions: sharply continental climate With low level average temperatures with dry air and significant watering of the territory in summer due to melted glacial waters, with the appearance of lakes and swamps in the lowlands. In this vast periglacial zone, a special biocenosis arose - the tundra-steppe, which existed throughout the glaciation and moved in accordance with changes in the boundaries of the glacier to the north or south. The flora of the tundra-steppe included various herbaceous plants (especially grasses and sedges), mosses, as well as small trees and shrubs that grew mainly in river valleys and along the shores of lakes: willows, birches, alders, pine trees and larch trees. At the same time, the total biomass of vegetation in the tundra-steppe was apparently very large, mainly due to grasses, which allowed an abundant and unique fauna, called mammoth, to settle in the vast areas of the periglacial belt.
This amazing periglacial fauna included mammoths, woolly rhinoceroses, musk oxen, short-horned bison, yaks, reindeer, saiga and gazelle antelopes, horses, kulans, rodents - gophers, marmots, lemmings, lagomorphs, as well as various predators: cave lions, cave bears, wolves, hyenas, arctic foxes, wolverines. The composition of the mammoth fauna indicates that it descended from the Hipparionian fauna, being its northern periglacial variant, while the modern African fauna is a southern, tropical derivative of the Hipparionian fauna.
All animals of the mammoth fauna are characterized by adaptations to life in low temperatures, in particular long and thick hair. The mammoth (Mammonteus, Fig. 93) was also covered with thick and very long red hair with a hair length of up to 70-80 cm. northern elephant, who lived 50-10 thousand years ago in vast areas of Europe, Asia and North America.
The study of representatives of the mammoth fauna is greatly facilitated by the preservation of entire corpses or their parts in permafrost conditions. A number of remarkable discoveries of this kind have been made on the territory of our country. The most famous of them is the so-called “Berezovsky” mammoth, found in 1901. on the banks of the Berezovka River in North Eastern Siberia, and the latest find is an almost complete corpse of a baby mammoth 5-7 months old, discovered in 1977. on the bank of a stream flowing into the Berelekh River (a tributary of the Kolyma).
In terms of body proportions, the mammoth was noticeably different from modern elephants, Indian and African. The parietal part of the head protruded strongly upward, and the back of the head was sloping down towards a deep cervical notch, behind which a large hump of fat rose on the back. This was probably a supply of nutrients used during the lean winter season. Behind the hump, the back was steeply sloping down. Huge tusks, up to 2.5 m long, curled up and inward. In the contents of the mammoths' stomachs, remains of leaves and stems of cereals and sedges, as well as shoots of willows, birches and alders, and sometimes even larches and pine trees, were found. The mammoth's diet was probably based on herbaceous plants.
In many places where mammoths previously lived: in Siberia, on the New Siberian Islands, in Alaska, in Ukraine, etc., huge accumulations of skeletons of these animals, the so-called “Mammoth cemeteries,” were discovered. Many assumptions have been made about the reasons for the emergence of mammoth cemeteries. It is most likely that they were formed, like most mass accumulations of fossil remains of terrestrial animals, as a result of the drift of river currents, especially during spring floods or summer floods, into various kinds of natural settling basins (pools, whirlpools, oxbow lakes, ravine mouths, etc. .), where whole skeletons and their fragments accumulated over many years.
Along with the mammoths lived woolly rhinoceroses (Coelodonta), covered with thick brown fur. The appearance of these two-horned rhinoceroses, as well as mammoths and other animals of this fauna, was captured by Stone Age people - Cro-Magnons in their drawings on the walls of caves. Based on archaeological data, it can be confidently stated that ancient people hunted a wide variety of animals of the mammoth fauna, including woolly rhinoceroses and mammoths themselves (and in America, mastodons and megatheriums that still survived there). In this regard, it has been suggested that humans could have played a certain role (according to some authors, even a decisive one) in the extinction of many Pleistocene animals.
The extinction of the mammoth fauna clearly correlates with the end of the last glaciation 10-12 thousand years ago. Climate warming and melting glaciers have dramatically changed the natural situation in the former zone of periglacial tundra-steppe: air humidity and precipitation have increased significantly, as a result, swampiness has developed in large areas, and the height of snow cover has increased in winter. Animals of the mammoth fauna, well protected from the dry cold and able to obtain food in the vast tundra-steppe during the snowless winters of the Ice Age, found themselves in an extremely unfavorable ecological situation for them. The abundance of snow in winter made it impossible to obtain food in sufficient quantities. In summer, high humidity and waterlogging of the soil, extremely unfavorable in themselves, were accompanied by a colossal increase in the number of blood-sucking insects (midges, so abundant in the modern tundra), whose bites exhausted the animals, not allowing them to feed in peace, as is now happening with northern deer. Thus, the mammoth fauna turned out to be very short term(the melting of glaciers occurred very quickly) in the face of sudden changes in the habitat, to which most of its constituent species were not able to adapt so quickly, and the mammoth fauna as a whole ceased to exist. Among the large mammals of this fauna, reindeer (Rangifer) have survived to this day, possessing great mobility and capable of long-distance migrations: in the summer to the tundra to the sea, where there are fewer midges, and in the winter to moss pastures in the forest-tundra and taiga. In relatively snow-free habitats in northern Greenland and on some islands of the North American archipelago, musk oxen (Ovibos) survive. Some small animals from the mammoth fauna (lemmings, arctic foxes) adapted to the new conditions. But most of the mammal species of this wonderful fauna became extinct by the beginning of the Holocene era.
(According to some data, in the Holocene 4-7 thousand years ago on Wrangel Island there was still a population of grinding mammoths) (See the book: Vereshchagin N.K. Why mammoths became extinct. - M.. 1979).
At the end of the Pleistocene, another significant change in the fauna occurred, albeit limited to the territory of America, but still remaining mysterious. In both Americas, the overwhelming majority of large animals that were so abundant there before have become extinct: representatives of the mammoth fauna, those living in more southern regions where there was no glaciation, mastodons and elephants, all horses and most camels, megatheriums and glyptodonts. Apparently, rhinoceroses disappeared in the Pliocene. Of the large mammals, only deer and bison have survived in North America and llamas and tapirs in South America. This is all the more surprising since North America was the birthplace and center of evolution of horses and camels, which have survived to this day in the Old World.
There is no evidence of significant changes in conditions at the end of the Pleistocene in most of the Americas that were not subject to glaciation. Moreover, after Europeans arrived in America, some of the horses they brought went wild and gave rise to mustangs, which quickly multiplied in the North American prairies, the conditions of which turned out to be favorable for horses. Indian tribes who lived by hunting did not have a significant impact on the numbers of huge herds of bison (and mustangs after their appearance in America). Man at the level of Stone Age culture could hardly have played a decisive role in the extinction of numerous species of large Pleistocene animals (with the possible exception of slow and slow-witted megatheriums) in vast territories of both Americas.
After the completion of the last glaciation 10-12 thousand years ago, the Earth entered the Holocene era of the Quaternary period, during which modern look fauna and flora. Living conditions on Earth are now much more severe than during the Mesozoic, Paleogene and most of the Neogene. And the richness and diversity of the world of organisms in our time, apparently, is significantly lower than in many past geological eras.
In the Holocene, the impact of humans on the environment becomes increasingly apparent. In our time, with the development of technical civilization, human activity has become truly important. global factor, actively, although in most cases ill-considered and destructively, changing the biosphere.
In connection with the formation of man modern look(Homo sapiens) and the development of human society during the Quaternary period A.P. Pavlov proposed to call this period Cenozoic era"anthropocene". Let us now turn to the evolution of man himself.
Mammoths went extinct about 10 thousand years ago during the last Ice Age. According to many scientists, Upper Paleolithic hunters played a significant or even decisive role in this extinction. According to another point of view, the extinction process began before the appearance of people in the corresponding territories.
In 1993, the journal Nature published information about a stunning discovery made on Wrangel Island. Reserve employee Sergei Vartanyan discovered the remains of mammoths on the island, the age of which was determined to be from 7 to 3.5 thousand years. Subsequently, it was discovered that these remains belonged to a special, relatively small subspecies that inhabited Wrangel Island when they already stood Egyptian pyramids, and which disappeared only during the reign of Tutankhamun (c. 1355-1337 BC) and the heyday of the Mycenaean civilization.
One of the latest, most massive and southernmost mammoth burials is located in the Kargat region Novosibirsk region, in the upper reaches of the Bagan River in the “Wolf Mane” area. It is believed that there are at least 1,500 mammoth skeletons here. Some of the bones bear traces of human processing, which allows us to build various hypotheses about the residence of ancient people in Siberia.
All new discoveries of fossil mammoths do not allow discussions about the fate of these ancient mammals to cool down. Scientists are getting closer to answering the question: why did the mammoth fauna disappear?11 species of mammoths have been described, but when talking about these animals, they usually mean the woolly or tundra mammoth, Mammuthus primigenius. It had the largest range, its remains were found more often than others, and it was the first to be described. It is believed that the environment in which woolly mammoths lived was the tundra-steppe - a relatively dry area, overgrown mainly with grasses. It appeared near glaciers, which, having trapped huge masses of water, dried up the surrounding lands. As evidenced by paleontological finds, in terms of the abundance of different animals, this region was not inferior to the African savannas. In addition to mammoths, rhinoceroses, bulls, bison, saigas, bears, lions, hyenas, and horses lived in the tundra-steppe. This complex of species is called the periglacial, or mammoth, fauna. But now these places are extremely poor in large animals. Most of them died out.
In the early 1990s Russian researchers made a sensational discovery, Radiocarbon dating of the teeth of woolly mammoths found on Wrangel Island in Severny Arctic Ocean, revealed that ancient elephants existed on this island as recently as 3,700 years ago. The last mammoths were dwarfs, one and a half times smaller than their continental predecessors. But 12,000 years ago, when Wrangel Island was connected to the mainland, large mammoths lived there.
LOST IN SIBERIA
Discussions about the extinction of mammoths have been going on for at least 200 years. Jean Baptiste Lamarck also wrote on this topic. He believed that biological species do not die out, and if the animals of the past are different from those living today, then they did not die out, but turned into others. True, now there are no animals that could be considered descendants of mammoths. But Lamarck found an explanation for this fact: the mammoths were exterminated by humans, or they did not become extinct, but were hiding somewhere in Siberia.
For their time, both explanations were quite acceptable. On the one hand, the destructive effect of man on nature was obvious even then. Lamarck was one of the first to thoroughly analyze this process. On the other hand, in Europe, ideas about Siberia were very vague. And it was during the time of Lamarck that data began to arrive about the finds of mammoth corpses, well preserved in permafrost - as if they had died not so long ago.
Lamarck's antagonist Georges Cuvier interpreted the same information differently: since the corpses were well preserved, they were not victims of predators, but died for other reasons, perhaps due to flooding. The essence of his theory boiled down to the following: in the history of the Earth there were fleeting cataclysms that could lead to changes in the fauna in a certain area.
Around the same time, the Italian paleontologist Giovanni Battista Brocchi expressed another idea: every species on Earth has its own deadline. Species and groups of species become extinct just as organisms die of old age.
All of the above points of view have supporters and opponents. At the beginning of the 20th century, one of Lamarck’s followers, the German paleontologist Gustav Steinmann, tried to prove that only the largest mammals, those that were hunted especially intensively, became completely extinct. The remaining animals known from fossil remains did not become extinct, but turned into others. Such ideas have not found wide acceptance. Cuvier's theory of “catastrophism” turned out to be more in demand, especially since it was supported by new data on the transformations that the Earth’s surface underwent throughout its long history.
Some researchers developed ideas about disharmony, “excessive evolution” or “inadaptability” of extinct creatures. The absurdity of individual animals was so exaggerated that the question arose: how could they exist at all? Mammoths have been used as one example of such disharmony. As if the huge tusks of these proboscis, having developed excessively, led them to an evolutionary dead end. But the authors of such works avoided one important point: "Odd" animals thrived for millions of years before disappearing.
And yet, their reasoning was based on a real fact: in the evolution of some groups of organisms, directions are found that lead to the maximum possible degree of development of a trait. For example, the size of the body, horns, tusks, teeth, and shells may increase over time. In this case, the reverse process does not occur, and when further increase becomes impossible due to physical reasons, the group is dying out. Austrian paleontologist Othenio Abel called this the law of inertia.
ON THE SPRUCE DIET
One of the most popular hypotheses explaining the extinction of the mammoth fauna is climatic. At the end of the last ice age, approximately 15,000-10,000 years ago, when the glacier melted, the northern part of the tundra-steppe turned into a swamp, and forests, mainly coniferous, grew in the southern part. Animal food instead of grass spruce branches, mosses and lichens, which allegedly killed mammoths and other representatives of the mammoth fauna.
Meanwhile, the climate had changed several times before, glaciers advanced and retreated, but mammoths and mammoth fauna survived and flourished. Let's say that the tundra and taiga are really not best place for large herbivores (however, reindeer, moose, and Canadian wood bison still live there). But the theory of evolution teaches that when the climate changes, living things must adapt to it or move to it. The territory at the disposal of mammoths was huge, almost half of Eurasia and most of the north-west of North America (in which, in addition to woolly mammoth At the same time, the Columbian mammoth lived - Mammuthus columbi).
If the climate changed, then the number of animals could decrease, but they are unlikely to disappear completely. Most of the territory where mammoths lived is now occupied by coniferous forests and swamps, but there are also other biotopes on it - meadows, floodplains, large areas of mixed forest, forestless foothills. Surely among these spaces there would be a place for mammoths somewhere. This species was very plastic and 70,000-50,000 years ago lived in the forest-steppe and forest-tundra, in swampy or, conversely, dry woodlands, in the taiga, mixed forests and tundra. Depending on the latitude, the climate in these territories varied from mild to severe.
But the main argument against the climate hypothesis is that the extinction of the mammoth fauna in many places occurred when significant climatic and landscape changes did not occur there. If so, then expansion taiga flora could be not a cause, but a consequence of the extinction of animals. If there are a lot of herbivores, then they eat not only grass, which can grow quickly, but also the sprouts of trees and shrubs. As a result, trees renew poorly and are reduced in number. In addition, proboscideans can fall big trees. In African reserves, rangers are forced to regulate the number of elephant herds, otherwise they simply eat up the savannah. Therefore, it could have happened that when mammoths became extinct and other herbivores became much smaller, a forest grew in place of the tundra-steppe.
Meanwhile, it is obvious that the extinction of mammoths and other large mammals coincides with the beginning of man’s attack on nature. Already tens of thousands of years ago, people had tools with which they could destroy
their neighbors on the planet. The ability to make flint spearheads, mastery of fire, the ability to hunt together and other qualities made ancient people competitors of predators.
DANGEROUS NEIGHBORS
Ancient people hunted mammoths especially often. Entire settlements were built from their skulls and skins. Maybe they killed everyone in the end? This explanation has been suggested by some modern researchers(although, as we said, this hypothesis is already 200 years old). Other scientists believe that “a handful of savages with sticks” were unable to exterminate an entire species of large animals.
It is not known exactly how many people were on Earth at that time, but thousands of primitive sites have already been found in sediments 12,000 years old. Perhaps in the time of mammoths there were enough “savages” to cause serious damage to nature. In the 19th century, for example, European travelers described the barbaric driven hunts of Indians, Eskimos and African tribes, which exterminated huge numbers of animals. Moreover, the natives did not care that most of them would not be used. Huge clusters herbivore bones different parts lights indicate that ancient people did not differ from their descendants in this regard. As the fauna became scarcer, the tribes migrated in search of places rich in game.
However, sometimes modern researchers paint a more complex picture of extermination. Man allegedly “shaken the ecological pyramids,” that is, somehow disrupted the existing ecological order. Ancient hunters along with beasts of prey supposedly they first destroyed the large herbivores, and then the predators themselves died out from malnutrition.
By the way, on Wrangel Island, archaeologists discovered traces of a Paleo-Eskimo settlement, but they were mainly engaged in marine fishing. There were no remains of mammoth bones at this site. Only the bone of a woolly rhinoceros (extinct much earlier) was found, which was probably something like a children's toy. The discovered site is 3200 years old, and the finds of the last mammoths date back to an earlier period - 3700 years ago. That is, no one bothered the last mammoths on the island; they died out on their own. The dwarf size of the mammoths from Wrangel Island, as well as the imprint of diseases on their remains, indicate that these animals suffered from a lack of food and inbreeding. And this small population of dwarfs gradually died out. Perhaps it was isolation that allowed her to outlive the rest of her relatives by several thousand years.
So, claims that climate or humans were the main reason for the extinction of mammoths are far from certain. When there are discrepancies in hypotheses, scientists often offer compromise solutions. There has already been a “traditional” conclusion to the work on the extinction of animals: supposedly in this process various unfavorable influences overlapped each other. In our case, the mammoths were damaged by the climate, and people persecuted them, and with the reduction in numbers, genetics also failed: inbreeding began, which led to degeneration. Okay, let's say mammoths were unlucky, but it is unclear why other non-extinct ones were lucky. Bison, musk oxen, reindeer...
VARIATIONS ON A THEME BY HAYDN
One consideration in modern science is not discussed at all, namely that mammoths became extinct “from old age.” Such interpretations of evolution are now considered heresy. However, this explanation seems to put everything in its place: during their evolutionary “youth,” mammoths did not care about the climate, and they were not afraid of primitive hunters. And then, when “youth” passed, their numbers began to steadily decline. Eventually, the last long-lived populations, like the one that lived on Wrangel Island, also died out.
There is plenty of evidence of such phylogenetic aging, and its number is increasing. Recently, American researchers have traced the extinctions of some mammals using spore-pollen analysis and many other modern methods. They came to the conclusion that on the North American continent the disappearance of large herbivores began even before people arrived there and occurred gradually. The extinction of mammoths and other mammals follows a typical picture that paleontologists describe for more ancient groups of animals, for example, dinosaurs or marine ammonite cephalopods. One researcher wittily compared it to Haydn's 45th Symphony, in which the musicians take turns leaving the orchestra before the work ends.
The mentioned American researchers consider climate to be the cause of extinction. However, the facts pointed out by the founders of paleontology remain facts. For some reason, the evolution of groups of organisms goes in a certain direction, just as it happens unidirectionally - from youth to old age individual development individuals. The characteristics of the mechanism of “phylogenetic aging” proposed by the classics of paleontology are rather vague. Here we can clarify something if we turn to modern gerontology - the science of aging of organisms. There are several dozen hypotheses proposed to explain the mechanism of aging of an individual. They often note that some cells cannot reproduce their exact copies indefinitely. With each division, either DNA breaks occur in them, or the length of certain sections of chromosomes shortens, or something else that eventually leads to the impossibility of further divisions. It is possible that because of this, rejuvenation of “worn out” cells, and therefore tissues and organs, becomes impossible. The result is old age and natural death. It may be that something in the entire genome is shortened with each copying, and this eventually leads to the impossibility of its reproduction, and therefore to the extinction of the species. And although today the question of the causes of extinction remains open, this last hypothesis deserves attention.
If this assumption is true, then attempts to “revive” mammoths are doomed to failure, but some scientists continue the experiments. In means mass media There were reports that the mammoth was about to be cloned. Japanese scientists managed to clone mouse cells that had been in the freezer for several years, and now they seem to be ready to move on to larger-scale projects.
However, this raises the eternal question of biology: to what extent can the results of laboratory experiments on a model object be extrapolated to what happens in nature? Several years in the freezer are not thousands of years in the tundra, where the remains could have thawed and frozen again many times. During prolonged stay in permafrost, cells cannot remain intact. Only fragments of molecules remain from them, so they cannot be cloned.
Basically, damage occurs due to the fact that the water contained in the cells crystallizes and ruptures the cellular structures. All mammoth corpses discovered so far are severely damaged when compared to a mouse from a freezer. Therefore, scientists are pinning their hopes on frozen mammoth sperm. They contain very little water and can withstand freezing better than regular cells. But the likelihood of such a discovery is negligible. So for now, cloning a mammoth looks like a lost cause.
So, about a million years ago, under the influence of cosmic and planetary factors, a noticeable cooling of the climate began in the Northern Hemisphere. Glacier caps and tongues grew on the mountain ranges, and the snow line sank. The currents of the oceans, the outlines of the coasts of the seas changed, and the river network was restructured. Under the influence of changes in the physical environment, plant and fauna.
Subtropical evergreen forests at the latitude of London, Moscow, Novosibirsk and Yakutsk were saturated with deciduous and coniferous species. A great change was coming in flora and vegetation. Instead of boundless forests, savannas and meadow-steppes began to appear on the watershed spaces of the hot plains. In this era of the late Pliocene - early Anthropocene, the hipparion fauna with its three-toed zebroid-looking hipparions, heavy mastodons and mahairods ( saber-toothed cats). They were not replaced by long-trunked elephants with slightly curved tusks, single-toed large and heavy horses with high columnar molars. Huge food resources of grassy meadows and valley gallery forests ensured the prosperity of leaf- and branch-eating deer, roe deer, and antelopes. The ancestors of the herbivorous aurochs and bison, who had previously eked out a miserable existence, quickly gained body size in the spaces of meadow-steppes and steppes, and the population size also increased. The open sun on the hillsides attracted burrowing rodents - gophers and stocky marmots.
Primitive humanoid creatures have already tried to spread from Africa and, possibly, from South Asia to the north - to Europe and Central Asia.
Many tens of thousands of years passed before the next wave of cooling occurred. Deciduous trees and shrubs, alternating with conifers, replaced evergreen vegetation in Europe, which remained only in places in the south along the coasts of warm seas.
The latitudinal zonation of the landscapes of Eurasia, close to the modern one - with deserts, steppes and meadow-steppes, mixed and taiga forests, tundra-steppes - was created already at the dawn of the Pleistocene. The fauna of these spaces was formed due to the adaptation of local species - their ecology and structural features - to new conditions, as well as due to the widest settlement within the named zones of some species and the extinction of others. Invasions of species from the south and from the tropics were small.
In the mountains of the Mediterranean, Caucasus, Tien Shan, Southern and Eastern Siberia, Khingan and Tibet, the Ancestors of monkeys (macaques), mountain ungulates (goats, rams and deer), carnivores and rodents appeared. Deserts and steppes were populated by horses, camels, antelopes, gazelles, bulls, gophers, and marmots. In some places, hippopotamuses and warthogs were still hanging out near lakes and swamps. Meadow and forest-steppes, gallery forests along river valleys were mastered by elephants - forest, trogontherium and mammothoid, Etruscan rhinoceros, elasmotherium, three or four species of horses and donkeys, wild boar, compound-horned and giant deer, mark-horned antelopes, primitive aurochs, yaks and bison.
The taiga zone, apparently, was in its infancy, and coniferous forests huddled along the gorges of ridges and river valleys. Their early Pleistocene fauna is little known, but there is no doubt that the ancestors of hazel grouse and wood grouse, martens and squirrels lived here. The far north, the meadow and tundra steppes of the then Arctic, had already been mastered by ancient horses, the ancestors reindeer and musk ox, the ancestors of lemmings are lagurodons and land beavers are trogonteria. In general, it was this early Pleistocene fauna that was the basis for the formation of the subsequent mammoth group.
A new series of climate coolings in the second half of the Pleistocene was accompanied by the development of mountain and lowland glaciations and drops in ocean levels. These cold snaps contributed to the further impoverishment of the animal world Northern Hemisphere heat-loving species and transforming the survivors into extremely cold-resistant forms.
A number of species of animals - the “early” mammoth, Knobloch’s camel, long-horned bison, cave lions and cave sheaves that crushed the bones of fallen giants - reached their largest sizes and biological flowering in the Middle Pleistocene (Mindel-Risse). By this time, tribes of primitive hunters had already invaded from the south and quickly settled across the vast expanses of southern Europe and the northern half of Asia.
The early mammoth fauna of the middle latitudes of Eurasia contained predominantly steppe and forest-steppe animals. Most the then - Middle Pleistocene - animals and birds were already adapted to the open landscapes of meadows and steppes.
The picture of the fauna of those cold steppes of the European and Asian Pleistocene probably resembled the modern savanna of equatorial Africa:
On the vast plains of the Dnieper and Volga regions, Southern Siberia Here and there hundreds of schools of horses and donkeys grazed. In some places, in the birch and aspen copses of the wide meadow floodplains, brown shocks of small herds of mammoths, tight-knit carcasses of single Elasmotheriums and rhinoceroses swayed. Big-antlered and red deer fed along the edges of the riverine willow grass. In the distance, in the haze of the open watershed spaces of the dry steppe, the ugly figures of shaggy camels slowly swam and the living masses of wandering thousand-strong herds of bison darkened. Gophers and marmots emerged from the ground in light columns and suddenly disappeared back with an alarming whistle when the shadow of an eagle flashed close, a fox ran by, or the tramp of a flock of saigas pursued by wolves was heard. Near a half-dried lake, spotted cave hyenas worked over the blackened carcass of an old bison, while a well-fed family of cave lions rested serenely in the shade of a single willow tree.
Blissful peace warm season gave way to anxiety in the temporary lack of food of harsh winters. Then, during snowstorms, all living things sought protection in oak groves, in birch groves, in steppe ravines and in hollows among the hills. In the spring, catastrophic floods occurred - floods and river valleys turned into cold seas for a long time, in which hundreds and thousands of large animals caught in the flood died.
The last ice age, which began 70-60 thousand years ago (Wurm, in Europe, and in our country, Valdai), left indelible marks on the landscape and organic world northern half of Eurasia. The late mammoth fauna formed and flourished throughout the Valdai Ice Age, that is, for almost 50 thousand years. Its living conditions were also steppe and tundra-steppe. With ocean levels falling by 130-150 m, British Isles, Sakhalin and the Japanese Islands formed one whole with the mainland. The vast zone of frozen tundra-steppes at this time extended from the British landmass through central Europe, the Russian Plain to Sakhalin and Japan and further to the northeast, including Taimyr, the New Siberian Islands and Alaska.
Permafrost caused the existence of coniferous and deciduous forests only in river valleys, gorges and on mountain slopes. From the margins of the glaciers, the winds carried loess dust, which was deposited among the lush grassy vegetation along the slopes and in river valleys. Despite the great dryness of the climate, with low temperatures the dust settled firmly on the thawing and damp soil. In winter, severe frosts tore the surface of the earth with deep cracks. Ice wedges from the water that flowed in in the summer, squeezing the columns of soil, went tens of meters deep. Living conditions were harsh, but with an abundance of grassy food, it was possible to live on hard soil. The inhabitants of this harsh zone have long acquired physiological and morphological adaptations to protect themselves from dry cold.
The entire composition of the late mammoth fauna can be divided into two large groups: consumers of primary (plant) biomass - herbivores and consumers of secondary (meat) biomass - carnivores who lived at the expense of the former. The list of the most characteristic animals of these frozen tundra-steppes, steppes and forest-steppes contains up to 50 species (p. 19). There were other, less noticeable and small-numbered species, such as the sheep - Sorgelia, and the antelope - Transbaikal harvest.
This composition is repeated in bone-bearing localities with amazing constancy almost all the way from the shores. Atlantic Ocean to the shores of the Pacific. Depending on the nature of the burial and its coordinates, there were, however, local variations. However, the “indicator” or “leading” species, namely the mammoth, hairy rhinoceros, horse, reindeer and red deer, primitive bison, arctic fox, wolf, cave hyena and cave lion, actually lived at that time in vast areas of the plains. Meanwhile, in the mountains and deserts lived their own species - mountain and desert animals: goats, rams, chamois, gophers, marmots, about which we know more from living species.
Judging by the frequency of encounters of their bones in geological outcrops, on river towpaths and in layers of Paleolithic sites, it is possible to give the following approximate table of the relative abundance of indicator animals on a ten-point scale.
In the specific essays further on brief information about some of these wonderful animals that ensured the existence and development of primitive man and humanity in the Stone Age. Myself primitive man during the heyday of the late mammoth fauna, he had already achieved a lot. He completely mastered fire, knew how to make elegant flint tools - points, chisels, knives, dart and spear tips - and came close to the invention and use of bows. He also invented many ingenious traps for animals and birds, and perhaps even used poisons. In Chapter IV we will talk about his hunts in more detail.