On the topic "Environmental crises in the history of mankind"

Pupils of grade 10 "A"

GOU SOSH No. 513

of Moscow

Vasilyeva Christina

I What is the ecological crisis and its causes.

II Environmental crises in the history of mankind.

III Environmental errors of some civilizations.

IV The problem of the Aral Sea and ways to solve it.

VI List of used literature.

What is the ecological crisis and its causes.

An ecological crisis is a violation of natural natural processes in the biosphere, resulting in rapid changes in the environment. There is tension in the relationship between mankind and nature, associated with the discrepancy between the volume of consumption of natural components by human society and the limited resource and environmental capabilities of the biosphere. At the same time, it is important to pay attention to the differences in scale between the global ecological crisis common to the biosphere and local or regional ecological disturbances and local ecological disasters.

Increase in local environmental disasters indicates the approach of a global environmental crisis and the possibility of a global environmental catastrophe. However, ecological crises can and have been successfully resolved in the history of mankind.

The growing modern ecological crisis in the relationship between nature and society is associated with the scientific and technological revolution. At the same time, crisis situations arising from depletion natural resources, are successfully resolved by improving technologies for the extraction, transportation, processing of traditional natural resources, the discovery and use of new ones, as well as the manufacture of synthetic materials.

There are several reasons for modern environmental crises:

Unrestrained and very fast growth population of the Earth
imperfect agricultural and industrial technologies
lightheadedness of mankind and disregard for the laws of the development of the biosphere

Environmental crises in the history of mankind.

1. The first environmental crisis.

The largest herbivores - mammoth, hairy rhinoceros, wild horse, as well as large predators - cave bear, cave lion, saber-toothed wild cat - disappeared by the end of the last glaciation, i.e. 10 - 20 thousand years ago. The latest discovery of mammoth remains dates back to the 7th millennium BC. e., and the remains of a large-mouthed deer - to the XVIII - X millennium BC. NS.

Supporters of the hypothesis about the extermination of large animals by a human hunter of the so-called "mammoth fauna" consider this phenomenon to be the first ecological crisis on the planet, or the crisis of consumers (from the Latin consumo - consumer). Even if we assume that the primitive hunter was the exterminator of the "mammoth fauna", then all the same it could not lead to an ecological crisis. Rather, it was a "food" crisis for those groups of hunters who specialized in large herbivores. It is now well known that ancient hunters changed the "profile" of the hunt: they passed from one species of animals to another. Consequently, after the natural extinction of the "mammoth fauna" there was no "food" crisis, just primitive people began to hunt medium-sized animals.

It should be emphasized that a person could not completely exterminate certain large mammals. A sharp decline in numbers as a result of hunting leads to the dismemberment of the species range into separate islets. The fate of small isolated populations is deplorable: if a species is not able to quickly restore the integrity of the range, an inevitable extinction occurs due to epizootics or a shortage of individuals of one sex with an overabundance of the other.

Mammoths, cave lion and cave hyena (Crocuta spelaea) were destroyed. Disappeared companion of man - a cave bear, twice the size of a brown bear. This species was confined to karst landscapes and became not only a human competitor in the use of shelters, but also an important hunting object. Mass destruction bison were exposed.

The gradual increase in the number of humans in the Upper Paleolithic, the extermination of some species and the decline in the number of others led humanity to the first ecological and economic crisis... Hunting species remained underdeveloped, for which driven-hunting was not effective - many ungulates of the plain and mountainous landscapes were difficult to get with a spear.

A cardinal way out of this ecological crisis was found by the Neolithic revolution.

2. Neolithic revolution and its ecological consequences.

Behind the Mesolithic in different terms in different territories, the Neolithic period began - the period of making polished stone tools, the invention of drilling stone, the appearance of an ax (which contributed to the deforestation), and later the invention of molding and annealing clay for making dishes. Accordingly, pre-ceramic and ceramic Neolithic are distinguished.

The domestication of animals led to the competitive displacement of their wild ancestors and relatives from their native habitats. The ancestor of the common goat, the bezoar goat (Capra aegargus), and the ancestor of the common sheep, the Asian mouflon (Ovis gmelini), were pushed back to the highlands of Western Asia. The domestication of the horse, a descendant of the European tarpan, led to the almost universal disappearance of the wild species that survived in the southern Russian steppes until the 19th century, but disappeared in most of its range at the end of the Neolithic. Wild relatives of domesticated species were also displaced. Thus, the Przewalski's horse (Equus przevalskii) survived until the middle of the 20th century in the ecological pessimum of its range - in the Gobi, but much earlier it was ousted by domestic horses and humans from its ecological optimum - the steppes of Khentei, Altai and Kazakhstan.

The largest ecological result of Neolithic pastoralism was the emergence of the Sahara Desert. As studies by French archaeologists have shown, even 10 thousand years ago there was a savanna on the territory of the Sahara, hippos, giraffes, African elephants, ostriches lived. Man, by overgrazing herds of cattle and sheep, turned the savannah into a desert. Rivers and lakes dried up - hippos disappeared, savannah disappeared - giraffes, ostriches, most species of antelopes disappeared. Following the disappearance of the North African savannas, the once abundant cattle disappeared.

The desertification of vast territories in the Neolithic was the cause of the second ecological crisis. Mankind emerged from it in two ways:

1) moving to the north, where, as the glaciers melted, new territories were liberated;

2) the transition to irrigated agriculture in the valleys of the great southern rivers - the Nile, Tigris and Euphrates, Indus and Ganges, Yangtze and Yellow River. It was there that the most ancient civilizations arose.

3. Environmental consequences of the era of great geographical discoveries.

This topic is unusually broad. The 507 years that have passed since the first voyage of Columbus have changed the world beyond recognition. The list of cultivated plants, domestic animals, synanthropic species exported from America and imported there is enormous. The many species acclimatized in the new location play a greater ecological, economic and cultural role than in their homeland. It is difficult to imagine Russia without potatoes, Ukraine without sunflower and corn, Bulgaria without tomatoes, Georgia without beans and tea, Uzbekistan without cotton, Canada without wheat, the "wild West" of the USA or Argentina without cattle and horses, Australia and New Zealand without sheep.

Columbus's sailors brought syphilis to Europe from the West Indies. The Spanish conquistadors brought smallpox to America. A 38-chromosomal black rat was brought to America from Europe with Spanish sailors. The Portuguese settled it in Africa and Western India. (The rats fleeing from the sinking ship are precisely the black rats.) The sailors of Southeast Asia settled on the islands of Oceania an East Asian 42-chromosome species of black rat. Together with the goods, the man settled in the world and not too loving sea ​​travel a gray rat, or a pasyuk. Synanthropic house mice settled from Eurasia. To combat rats, mice and snakes, the mongoose was imported from India to tropical islands. Mongooses successfully ate rats, then destroyed endemic species of rodents and birds, and then died out themselves.

The fauna of the islands is especially vulnerable. In Madagascar, the Malgashi (the main population of the Republic of Madagascar) in X-XII centuries destroyed the giant flightless ostrich birds of the epyornis. In New Zealand, the Maori (the main population of New Zealand before the arrival of the Europeans) destroyed the giant moa. TO XVII century on the island of Mauritius, the giant flightless pigeon dodo, or dodo, was destroyed. In the 18th century, the Russians destroyed a sea cow on the Commander Islands, in the 19th century, European colonists destroyed the aborigines of Tasmania, and in the 20th century, due to competition with the dogs brought here (there was no dingo here!), The marsupial wolf disappeared.

Environmental mistakes of some civilizations.

1. Extermination of sparrows in China.

Sparrow killing is the highlight of the massive pest control campaign in China initiated by Mao Zedong as part of the Great Leap Forward (1958-1962).

The idea of ​​the campaign was to eliminate the "four pests" - rats, mosquitoes, flies and sparrows. The campaign against the sparrows has become the most widespread. The propaganda explained that the sparrows devour the grain of the crop en masse, bringing colossal losses to the national economy. The plan was developed in 1958. He was supported by the President of the Chinese Academy of Sciences, academician Guo Moruo.

It was known that a sparrow cannot stay in the air for more than a certain period of time, about 15 minutes. All peasants, as well as schoolchildren and townspeople involved in the campaign, had to shout, beat pots, drums, etc., swing poles and rags, standing on the roofs of houses - in order to scare the sparrows and not give them shelter. Tired birds fell to the ground dead or sought out enthusiastic participants in the action. On display were photographs of several meters high mountains of dead sparrows.

During the campaign deployed in March-April 1958, 900 thousand birds were destroyed in Beijing and Shanghai in just three days, and by the first ten days of November of the same year in China, according to incomplete statistics, 1.96 billion sparrows were exterminated.

A year after the campaign, the harvest did improve, but the caterpillars and locusts, feeding on the shoots, proliferated. Previously, caterpillar and locust populations were regulated by sparrows. As a result of the invasion of locusts, yields fell sharply, and famine struck the country, from which an estimated 30 million people died.

Collectivization was another cause of the famine, which also led to a sharp decline in harvests.

At the end of 1959, a series of discussions took place at the Chinese Academy of Sciences, as a result of which the campaign was deemed to be in error. On March 18, 1960, Mao Zedong made a personal decision to suspend the fight against sparrows. Mao Zedong then said that the sparrows should not be destroyed, and the four pests are rats, mosquitoes, flies and beetles.

To restore the population of sparrows, these birds had to be imported into the country from Canada and the USSR.

V early XXI century in China began a massive campaign to protect sparrows

2. How mongoose was used against rats.

Sugarcane is not a native plant Latin America... It was brought in by Spanish conquistadors and settlers. Forests were intensively cut down for crops of reed, as well as for firewood during the preparation of molasses and boiling of reed juice. But soon the planters discovered that they had to share a significant part of the sugarcane crop with the voracious rats, local aborigines and imported from overseas.

In 1872, four male and five female mongooses were transported by steamer from Calcutta in special cages. They became the ancestors of many millions of mongooses now living in the New World.

The mongooses have justified the task entrusted to them. In Jamaica, the number of rats has dropped significantly, and several species of rats have disappeared altogether. The population of gray rats was undermined, black rats left the sugar cane plantations and went into the forests.

In Martinique, Saint Lucia, Grenada, Trinidad and other islands, there are very fast venomous fever snakes. At one point, there was an "outbreak" of these poisonous snakes. A shipment of mongooses was hastily delivered to fight the poisonous snakes. But the heatworm is faster than the cobra and the mongoose, habitual to the attacks of the cobra, did not have time to react. In battles with mongooses, island snakes often emerged victorious.

Having finished with the rats, the mongooses went on to hunt for local animals: they began to devour birds that nest on the ground, land crabs, frogs, and lizards. When they "ate up all the pasture", they were taken from hunger even for sugarcane. We went on to hunt for domestic animals. They hunted piglets, lambs, water pigs, chickens. In Cuba and Haiti, rare gnaw-toothed animals were exterminated.

Where mongooses have taken root, they have filled everything: forests, plantations, fields, settlements. They could be seen everywhere scurrying along the roads and fields, on the plains and mountains, in houses and gardens.

Mongooses destroyed great amount representatives of the insular fauna of the Greater and Lesser Antilles. Where there are mongooses, there is no Jamaican rice rat, which is not found anywhere else, there is no sweet-voiced wren: you will no longer hear its sonorous, pleasant songs.

Pigeons and spotted thrush nesting on the ground have been driven to extinction by the mongoose. Known and famous on the island of Jamaica, the yellow poisonous snake Jamaica is a local enemy of rats, eliminated by mongooses. Giant toads are disappearing, at one time brought to fight with rats from South America... Mongooses do not eat adult toads, they are poisonous for them, but the young toad fell to the taste of the mongooses.

3. War as a cause of environmental crises.

The worst desecration of humanity is war. Unlike any animals, a person is capable of killing people like him with incredible cruelty. Scientists have calculated that over the past 6 thousand years, people have experienced 14,513 wars, in which 3,640 million people died.

An example of an environmental crisis caused by a military conflict is the events that took place in Kuwait and the surrounding Gulf territories after Operation Desert Storm in early 1991. While retreating from Kuwait, the Iraqi invaders detonated over 500 oil wells with explosives. A significant part of them flared up and burned for six months, poisoning a large area with harmful gases and soot. From boreholes that did not ignite, oil gushed out, forming large lakes, and flowed into the Persian Gulf. A large amount of oil from the blown-up terminals and tankers also poured here. As a result, oil covered nearly 1,554 km 2 of the sea surface, 450 km of the coastline, where most of the birds, sea turtles and other animals died. Fire torches burned 7.3 million liters of oil daily, which is equal to the volume of oil that the United States imports daily. Clouds of soot from fires rose to a height of 3 km and were carried by winds far beyond Kuwait's borders - black rains fell in Saudi Arabia and Iran, black snow - in Kashmir (2,000 km from Kuwait). The atmosphere polluted with oil soot had a harmful effect on human health, since the soot contained many carcinogens.

Experts found that this disaster was accompanied by the following phenomena:

1. Thermal pollution (86 million kW per day). The same amount of heat is released due to a forest fire on an area of ​​200 hectares.

2. Soot from burning oil - 12,000 tons daily.

3. Carbon dioxide - 1.9 million tons daily (this is 2% of the total CO 2 that is released into the Earth's atmosphere due to the combustion of mineral fuel by all countries of the world).

In general, the pollution of the environment during this disaster equaled, according to experts, 20 accidents of the Exxon Valdez tanker.

The Aral Sea problem and ways to solve it.

Not so long ago, the Aral Sea was the fourth largest lake in the world, it was famous for its richest natural resources, and the Aral Sea zone was considered a prosperous and biologically rich natural environment. The unique isolation and diversity of the Aral Sea did not leave anyone indifferent. And it is not surprising that the lake received such a name. After all, the word "Aral" in translation from the Turkic language means "island". Probably, our ancestors considered the Aral to be a saving island of life and prosperity among the desert hot sands of the Karakum and Kyzylkum desert.

Help on the Aral Sea. The Aral is an endless salt lake-sea in Uzbekistan and Kazakhstan. By 1990, the area was 36.5 thousand square meters. km; until 1960, the area was 66, 1 thousand square meters. km. The prevailing depths are 10-15 m, the largest is 54.5 m. Over 300 islands. However, due to unreasonable human activities, especially in recent decades, the situation has changed dramatically. By 1995, the sea had lost three quarters of its water volume, and the surface area had been reduced by more than half. Now more than 33 thousand km 2 of the seabed have been exposed and subjected to desertification. The coastline retreated by 100-150 km. The salinity of the water has increased 2, 5 times. And the sea itself was divided into two parts - the Big Aral and the Small

The consequences of the Aral Sea disaster have long gone beyond the region. Over 100 thousand tons of salt and fine dust with admixtures of various chemicals and poisons are carried annually from the dried up sea area, like from a volcano crater, adversely affecting all living things.

Analysis of the dynamics of crushing of the Aral Sea and desertification of adjacent regions leads to a sad forecast complete disappearance seas by 2010-2015. As a result, it is formed new desert Aral-kum, which will be a continuation of the deserts of the Karakum and Kyzylkum. Everything large quantity salts and various highly toxic poisons will spread throughout the world for many decades, poisoning the air and destroying the ozone layer of the planet. The disappearance of the Aral Sea also threatens with a sharp change in the climatic conditions of the adjacent territories and the entire region as a whole. A strong tightening of the already sharply continental climate is already noticeable here.

Scientists have proposed many ways and private solutions to save the Aral Sea. Among them, two proposals stand out: to connect the Caspian and Aral Seas and in this way restore the disturbed water balance; to carry out massive drilling of wells adjacent to the Aral Sea, and, possibly, in the water area of ​​the former Aral Sea, and with the help of this, gradually fill the reservoir.

Both of these and a number of other methods have significant drawbacks, the main of which are: supply of salt and bitter-salted water unsuitable for consumption and irrigation to the Aral Sea; extremely high construction costs and energy consumption of water supply; unproductive water losses on the way to the Aral Sea due to evaporation, leakage and filtration into lower aquifers.

Conclusions.

Until the 20th century, the Earth did not know environmental disasters. Every year, the impact of man on the natural environment around him is increasing, the use of natural resources is expanding, new types of energy are included in the orbit of people's economic efforts. These phenomena have entailed profound, mostly extremely undesirable changes in natural conditions - pollution of the atmosphere, water bodies and ground spaces with industrial, transport and household waste, as well as pesticides, disturbance of landscapes due to mining, destruction and decrease in productivity in large areas in as a result of erosion and other processes of the soil cover of the Earth, a reduction in the development of industry and agriculture of the areas occupied by forests, floodplain, upland and mountain meadows, a decrease in the number of wild animals. Human influence began to increasingly reflect on the state and functioning of ecological systems as a whole.

But a person, with each new ecological crisis, is more and more aware of what he is doing with nature, but he is not able to change his lifestyle and start learning from his mistakes. The extinction of many species of animals, pollution of the aquatic environment and the atmosphere - all this is the work of the "ruler of nature", the man himself.

Environmental crises, like the mistakes of mankind, are very dangerous for nature as a whole. They are incorrigible. Each damage done to our Earth is another step of our civilization into the abyss, a step towards the apocalypse.

But what can we do to reduce the likelihood of environmental crises occurring?

A key element in the fight against environmental crises is the search for competent and effective scientific and technical solutions. This means that numerous institutes, laboratories, universities and firms must work for the environment. Any existing or reconstructed enterprise, each new construction project, regardless of its social orientation, should be subject to environmental expertise. And finally, the ecological component of secondary, special and higher education should become an integral part of the training of any specialist in the field of technology, natural sciences, medicine, economics and even humanities. Special meaning has an environmental teacher training. The ecological crisis is the greatest threat facing humanity today. The analysis shows that other global crises - energy, raw materials, demographic - are basically reduced to the problems of nature conservation. The inhabitants of the Earth have no alternative: either they will deal with pollution, or pollution will deal with for the most part earthlings.

List of used literature.

1. Lopatin I.K. Diversity of the Animal World: Past, Present, Conservation Issues. Soros Educational Journal. 1997. No. 7. S. 18-24.

2. Lot A. In search of the frescoes of Tassili-Ajer. L .: Art, 1973.110 p.

3. Bibikov S.N. Some aspects of paleo-economic modeling of the Paleolithic. Sov. archeology. 1969. No. 4.

4. Budyko M.N. On the reasons for the extinction of some animal species at the end of the Pleistocene. Izv. Academy of Sciences of the USSR. Ser. geogr. 1967. No. 2.

5. Vorontsov N.N. Environmental crises in the history of mankind.

6. Dorokhov Y. Ecological disasters of antiquity .

7. Lisichkin G.V. Environmental crisis and ways to overcome it.

8. Informational portal"Ecological problems"

9. Information portal "Wikipedia"

10. Information portal "Ecology.SU"

The word "ecology" is most often used not in a strict sense, but in a narrower one, denoting the relationship between man and the environment, those changes that occur due to anthropogenic pressure in the biosphere, as well as the problems of people, which have their source of force of nature. People are often inclined to idealize the "bright past", and vice versa, to experience apocaleptic moods in relation to the "hazy future".

Fortunately or not, it shows us that "every century is an iron century", and if we are talking about ecology, then ecological disasters in regional at least, scales, took place even before the birth of Christ. Since ancient times, man has only done what he has changed, transformed the nature around him, and since ancient times the fruits of his activity have returned to him like a boomerang. Usually, anthropogenic changes in nature were superimposed on natural rhythms proper, intensifying unfavorable tendencies and hindering the development of favorable ones. Because of this, it is often difficult to delineate where negative influences civilization, and where actually natural phenomena... Even today, controversy continues, for example, over whether the ozone holes and global warming a consequence of natural processes or not, but the negativity of human activity is not questioned, the dispute can only go about the degree of influence.

Perhaps (although this fact has not been proven absolutely reliably), man made a great contribution to the emergence of the largest Sahara desert on the planet. Frescoes and cave drawings, found there and dating back to the 6-4 millennium BC, show us the rich fauna of Africa. The frescoes depict buffaloes, antelopes, hippos. As studies show, the desertification of the savannah on the territory of modern Sahara began about 500,000 years ago, but the process took on a landslide character from 3 BC. NS. The nature of life of the nomadic tribes of the South of the Sahara, the way of life, which has not changed too much since then. As well as data on the economy of the ancient inhabitants of the North of the continent, it can be assumed that slash-and-burn agriculture, felling of trees, contributed to the drainage of rivers on the territory of the future Sahara. And the immoderate grazing of livestock led to the knocking out of fertile soils by their hooves, the result of this was a sharp increase in soil erosion and land desertification.

The same processes destroyed several large oases in the Sahara and a strip of fertile land north of the desert after the arrival of the nomadic Arabs. The advance of the Sahara to the south today is also associated with the economic activities of the indigenous peoples. "The goats ate Greece" - this saying has been known since ancient times. Goat breeding destroyed woody vegetation in Greece, goats' hooves trampled the soil. The process of soil erosion in the Mediterranean in ancient times was 10 times higher in cultivated areas. There were huge landfills near the ancient cities. In particular, near Rome, one of the dump hills was 35 meters high and 850 meters in diameter. Rodents and beggars who fed there spread disease. Waste discharges into city streets, discharges of urban waste water into reservoirs, from where the same residents then took water. In the same Rome, there were about 1 million people, you can imagine how much they produced garbage.

Deforestation along the river banks has turned the once navigable water streams into shallow and drying up. Irrational reclamation led to soil salinization, the use of a plow turned over soil layers (it was actively used since the beginning of our era), deforestation led to massive soil degradation, and, according to many researchers, led to the decline of ancient agriculture, the economy as a whole and the collapse of the entire ancient culture ...

There were similar phenomena in the East. One of the largest and most ancient cities of the Harrap civilization (II-III millennium BC), Monchefno-Daro was flooded with water several times, more than 5 times, and each time for more than 100 years. The floods are believed to have been caused by the siltation of watercourses due to inept reclamation. If in India the imperfection of irrigation systems led to flooding, then in Mesopotamia to soil salinization.

The creation of powerful irrigation systems led to the emergence of extensive salt marshes due to a violation of the water-salt balance. Finally, due to environmental disasters caused by human activities, several highly developed cultures simply died. Such a fate befell, for example, the Mayan civilization in Central America and the culture of Easter Island. The Maya Indians, who built many stone cities, using hieroglyphics, who knew mathematics and astronomy better than their European contemporaries (first millennium AD), subjected the soil to such exploitation that the depleted land around the cities could no longer feed the population. There is a hypothesis that this caused the migration of the population from place to place, and led to the degradation of culture.

Since the Upper Paleolithic era, human economic activity has repeatedly led to the deterioration of natural conditions, which created more or less difficulties for further implementation. human society.

In this way, many environmental crises arose, spreading to territories of various sizes.

Since ancient times important factor human impact on surrounding nature there was fire, the use of which made it possible to destroy vegetation over large areas. Forest and steppe fires have long been widely used as a means of hunting large animals. Until recently, this method was used by Australian aborigines, who for this purpose destroyed vegetation in areas of tens of square kilometers. Similar hunting techniques were probably used by hunters of the Upper Paleolithic.

It is obvious that fires in large areas led to the predatory destruction of wild animals and the destruction of natural ecological systems.

Along with this, the destruction of forests facilitated further hunting for large animals, which may explain the rapid disappearance of forest vegetation in many areas after the appearance of modern humans.

In the Neolithic era, when the basis economic activity cattle breeding and agriculture became, the burning of vegetation became enormous.

It was used to expand pastures at the expense of forest plots, and especially for slash-and-burn agriculture, based on cutting down forest areas and burning felled trees, after which the soil fertilized with ash gave abundant yields even with very shallow cultivation.

Soil fertility under this farming system is rapidly decreasing, and therefore, after a few years (sometimes only after one or two years), new forest areas have to be cut down and cultivated fields have to be transferred there. This method can be applied in the presence of vast sparsely populated forest areas. In the recent past, it was distributed in many countries of the middle latitudes and is used even now in some developing countries of the tropics.

The widespread use of burning vegetation over a significant part of the land area has led to noticeable changes in natural conditions, including flora, fauna, soil and, in lesser degree as well as climate and hydrological regime. Since the systematic burning of vegetation, both in the middle latitudes and in the tropics, began long ago, it is difficult to estimate the entire volume of environmental changes caused in this way, surrounding man... It is noteworthy that, as the observational data show, in many cases, the vegetation cover destroyed by man is not restored even after the termination of its systematic burning.

Along with slash farming in a number of areas, forests have been destroyed for timber use. The natural vegetation cover of many areas was greatly influenced by the grazing of farm animals, which was often carried out without taking into account the possibility of restoring the vegetation cover. In forested areas with dry climates, the devouring of young trees by goats and other animals ultimately led to the destruction of forests. Excessive cattle grazing destroyed the vegetation of dry steppes and savannas, which then often acquired the features of semi-deserts and deserts.

The impact of economic activities on the vegetation cover, apparently, has repeatedly caused severe damage to human society.

One of the first civilizations in the history of mankind arose in northwestern India (third or second millennium BC). The centers of this civilization (Harappa, Mohenjo-Daro, etc.) were located in the areas now occupied by the desert.

It has been suggested that in the past these areas were dry steppes, where there were favorable conditions for the development of animal husbandry and some types of agriculture.

Excessive grazing in the era ancient civilization could lead to the destruction of the vegetation cover, which led to an increase in temperature and a decrease in the relative humidity of the lower air layer. As a result, the amount of precipitation decreased, which made it impossible for the restoration of vegetation cover. In this regard, it is possible that anthropogenic climate change was one of the reasons for the disappearance of the ancient civilization of India.

Another example relates to the changes in natural conditions in the Mediterranean basin in ancient times, at the beginning of which vast forests existed on the territory of Greece and a number of other Mediterranean countries, which were then partially cut down and partially destroyed as a result of excessive grazing. This contributed to severe soil erosion and led to the complete destruction of soil cover on many mountain slopes, which increased the aridity of the climate and significantly worsened the conditions for agricultural production. Although in in this case the change in natural conditions did not lead to the destruction of ancient civilizations; it had a profound impact on many aspects of human life in ancient times.

There is an assumption that the depletion of soils on the territory of the Central American state of the Maya as a result of slash-and-burn agriculture was one of the reasons for the death of this highly developed civilization.

The Europeans who settled in Central America found numerous cities in the tropical jungle, and have long been abandoned by their inhabitants.

The examples given here, the number of which can be easily multiplied, relate to the significant deterioration of environmental conditions created by man, which, at the level of technical capabilities of the time, turned out to be irreversible. Such cases can be called anthropogenic ecological crises.

Studying the anthropogenic ecological crises of the past, it is possible to make a proposal that the crises arising at the early stages of the development of human society, especially the crisis of the Upper Paleolithic era considered above, had especially severe consequences. More recent environmental crises have affected smaller areas and appear to have had shorter impacts.

The history of human influence on the biosphere shows that the technical process is constantly increasing the possibilities of influencing environment, creating the preconditions for the emergence of major environmental crises. On the other hand, this process expands the possibilities for eliminating human-induced impairments. natural environment... These two opposite tendencies were most clearly manifested in the second half of the 20th century.

Environmental crises in human history

The global ecological crisis that gripped the biosphere of our planet today makes us turn with particular interest to the history of past ecological crises. Such crises happened in the history of the Earth long before the appearance of man and led to the mass extinction of many systematic groups at the turn of large geological eras... The most famous crisis at the end of the Cretaceous period, which caused the extinction of dinosaurs and the accompanying biota of the Mesozoic and opened the way for the accelerated development of angiosperms, higher insects, mammals and birds in the Cenozoic. We will not dwell on all the reasons for the ecological crises of the prehistoric past, but will focus on the crises of anthropogenic origin associated with the activities of ancient man. In order to assess the impact of anthropogenic pressure on nature, it is important to imagine the number of people and their accompanying species at different stages of human history.

How can you determine the number of people in the past?

Today, the number of people is approaching 6 billion. And what was the number of our ancestors during the existence of a skilled person ( Homo habilis)? How to define it?

One can proceed from a comparison of the number of humans with the number of other large mammals, in particular the great apes.

Today in Borneo, where the virgins still survive rainforests, about 2 million people live and 20 thousand orangutans are preserved ( Pongo pygmueus). It is clear that if it were not for human pressure (deforestation, anxiety factor, transmission of tuberculosis and hepatitis B from humans to orangs), the number of this monkey in Borneo could reach 80-100 thousand individuals. If we take into account the former distribution of the orang in Sumatra and the Malay Peninsula, then the initial number of this large apes (before the appearance of Pithecanthropus there) could be estimated at 300-500 thousand individuals. However, orangs (as well as chimpanzees and gorillas) are vegetarians, whereas our ancestors were omnivores and animal food constituted an important part of their diet. Consequently, the individual plot of hunters and gatherers was significantly larger than that of vegetarians-anthropoids. From here we come to figures of the order of 100 thousand individuals for a skilled person ( Ho-mo habilis).

The ability to maintain fire contributed to the resettlement of Homo erectus ( Homo erectus) in the temperate zones of the Old World and its growth. Archaeologists estimate the number of humans around 300,000 years ago, i.e. at the time of Sinanthropus ( H. erectus pekinensis), in 1 million individuals. In the Upper Paleolithic era, Cro-Magnons and similar forms of Homo sapiens ( N. sapiens) were widely settled in the Old World and reached, according to the archaeologist F.K. Howell, 3.34 million individuals. This accuracy seems excessive, but the very estimate of the order of abundance is paleolithic man seems plausible.

How is the need of ancient hunters for food resources calculated and the pressure of anthropogenic pressure on the fauna is determined?

During the years of the International Biological Program (IBP) - 1960-1970s. - according to a unified methodology in different countries world for different climatic and landscape zones, calculations were made of the increase in phytomass for the year and the increase in biomass of consumers of plants, predators and in other links of food chains. Based on these data, M.N. Budyko calculated the needs of ancient hunters for food resources.

The increase in the biomass of mammoths per year was 4000 kg per 100 km2. For meat, 40% of the weight was used, which gives a food resource of 2500 kg / year per 100 km2. The minimum requirement for meat for the diet of hunters was determined by S.N. Bibikov and V.M. Masson at 600-700 g / day. Therefore, the minimum requirement for the meat of a horde of 25 people is 5930 kg / year, and in terms of live weight - 14 800 kg / year. To fulfill such needs, a horde of 25 people had to develop a hunting territory of 370 km2, killing about six adult mammoths a year. Food resources of other species of game animals can be calculated in a similar way.

If we accept that the human population of the Cro-Magnon era was 2.5 million individuals, and assume that for only 10 years, humanity would have eaten only mammoths (in temperate zone) or Indian and African elephants (in the tropics and subtropics), then during this time a person would need to destroy 6 million mammoths and elephants. However, Proboscids have hardly ever reached such a total number. To be convinced of this, let's compare these figures with the number of individuals of some living species of large mammals that could be commercial. It is known, for example, that on the territory of Eurasia the number of elk ( Alces dices and A.americanus) is about 800-900 thousand individuals. If we add to them the number of moose in Canada and the United States, we get a figure of about 1 million 200 thousand individuals of two species. Saiga antelope ( Saiga tatarica) during the years of restoration of its numbers (before its catastrophic destruction for the sake of fishing for horns for the needs of oriental medicine in the late 1980s - early 1990s), there were up to 2 million individuals. It can be assumed that before the development of sheep breeding, the number of saiga could reach 5, maximum 10 million individuals. The number of small taiga deer - musk deer ( Moschus moschifer) - estimated at 40-80 thousand individuals.

Environmental consequences of Paleolithic human activity.
The first environmental crisis

During the Pliocene, and especially during the Pleistocene, ancient hunters exerted significant pressure on nature. The idea that the extinction of the mammoth, woolly rhinoceros, cave bear, cave lion is associated with warming and the end of the Ice Age was first questioned by the Ukrainian paleontologist I.G. Pidoplichko back in the late 1940s and early 1950s. Unreasonably opposing the very fact of the existence of ice ages, Pidoplichko, at the same time, expressed a seemingly seditious hypothesis that man was guilty of the extinction of the mammoth. The Leningrad zoologist and paleontologist N.K. Vereshchagin. Later discoveries have confirmed the validity of their assumptions.

The development of methods of radiocarbon analysis showed that the last mammoths ( Elephas primigenius) lived at the very end of the Ice Age, and in some places survived until the beginning of the Holocene. The remains of a thousand mammoths were found at the Předmost Paleolithic site (formerly Czechoslovakia). Known studied by E.V. Alekseeva mass remains of mammoth bones (more than 2000 individuals) at the Volchya Griva site near Novosibirsk, 12 thousand years old. The last mammoths in Siberia lived only 8-9 thousand years ago. The destruction of the mammoth as a species is undoubtedly the result of the activities of ancient hunters.

Recent research in Tropical Africa has demonstrated the role of African elephants in jungle ecology. Elephants made paths through the jungle, along which many species living on the edges of the forest penetrated into the depths of the rainforests. The extermination of elephants for the sake of the notorious "ivory" led to overgrowing of forests, a decrease in the biological diversity of the tropics, since elephant trails served as migration routes for many ungulates, and beyond them, and predators. It can be assumed that the extermination of mammoths also led to the loss of the landscape and biological diversity of the forests of Siberia and other regions of Eurasia.

The art of the Upper Paleolithic animalists serves, along with paleontological and archaeozoological finds, important source information about the hunting species of our ancestors. Until recently, the Late Paleolithic drawings from the Lascaux Cave in France (17,000 years old) and from the Altamira Cave in Spain (15,000 years old) were considered the oldest and most complete. But in December 1994 it was discovered by French cavers, and in 1995-1996. the Chauvet Cave, the oldest known gallery of Upper Paleolithic art, has been explored. The age of its frescoes, dated by radiocarbon, is 31,000 years! Chauvet Cave gives us a new spectrum of images of mammalian fauna from this time. Along with relatively rare drawings of a mammoth (among them is an image of a mammoth, strikingly similar to that found in permafrost Magadan region the body of the mammoth "Dima"), the Alpine ibex ( Capra ibex), massive images of two-horned rhinos, cave bears ( Ursus spelaeus), cave lions ( Panthera spelaea), tarpanov ( Equus gmelin).

The images of rhinoceroses in the Chauvet Cave raise many questions. This is undoubtedly not a woolly rhinoceros - the drawings depict a two-horned rhinoceros with larger horns, without traces of fur, with a pronounced skin fold, characteristic of living species for the one-horned Indian rhinoceros ( Rhinocerus indicus). Perhaps this is Merka rhino ( Dicerorhinus kirchbergensis), who lived in southern Europe until the end of the Late Pleistocene? However, if quite numerous remnants of skin with hairline, horny outgrowths on the skull have been preserved (even the world's only stuffed animal of this species is kept in Lviv), then only bone remains have survived from the Merck rhinoceros, the keratin "horns" have not survived. Thus, the discovery in the Chauvet cave raises new questions for us about what kind of rhinoceros were known to its inhabitants. Why are the rhinoceroses from the Chauvet Cave depicted in herds? It seems highly probable that Paleolithic hunters are to blame for the disappearance of the Merck rhinoceros.

The woolly rhino is an animal, unlike the gregarious mammoth, a solitary family - never reached such a high number as proboscis. During the Paleolithic, its numbers declined sharply as a result of hunting. Perhaps, by the turn of the Paleolithic and Neolithic, it practically disappeared. However, there are dubious indications of Arab authors that the woolly rhino was still preserved in the Volga Bulgaria up to the 10th century. AD

It should be emphasized that a person could not completely exterminate all populations of one or another species of large mammals. A sharp decrease in the number as a result of hunting led to the division of the species range into separate islets. The fate of small isolated populations is deplorable: if a species is not able to restore the integrity of the range in a limited period, small populations can die out due to epizootics or purely statistical reasons (lack of individuals of one sex with an overabundance of the other). There is a process of "insularization" - the division of the area into islets and the inevitable extinction of small groups of animals in them.

Mammoths, a cave lion and a cave hyena were destroyed ( Crocuta spelaea). The man's companion, the cave bear, which was twice the size of the brown bear, disappeared. This species was confined to karst landscapes and became not only a human competitor in the use of shelters, but also an important hunting object. The bison have undergone mass destruction.

One of the most thoroughly studied archaeozoologically is Moldova. On the territory of the Prut-Dniester interfluve, Paleolithic sites of the Acheulean and Mousterian times are known, where the remains of up to 6,000 individuals of the cave bear were found. Research by the Moldavian paleontologist A.N. David showed that by the very end of the Upper Paleolithic the cave bear disappeared from the diet of primitive man. In a similar way, as shown by the research of N.K. Vereshchagin, there was a disappearance of the cave bear in the Caucasus.

Intense anthropogenic pressure was also experienced by other species of mammals, whose numbers were undermined by ancient hunters, although they were not completely destroyed. At the Solutre site (middle of the Upper Paleolithic) in France, the remains of about ten thousand were found wild horses- tarpan. The remains of thousands of bison were found at the Amvrosievskaya site in Ukraine.

Round-up hunting for large mammals could feed limited human populations. For the Acheulean period of the Upper Paleolithic of the Prut-Dniester interfluve (the territory of Bessarabia) V.M. Masson calculated the possibility of the existence there of 10-12 hunting hordes with a total number of 250-300 people. During the Mousterian era, the population of this territory increased by one third and amounted to 320-370 people. The basis of their food was cave bear, tarpan, bison, reindeer, which accounted for 70 to 83% of production. The increase in the human population increased the anthropogenic pressure and led to the almost complete extermination of the cave bear.

The gradual increase in the number of humans in the Upper Paleolithic, the extermination of some species and the decline in the number of others led humanity to the first ecological and economic crisis in its history. Hunting species remained underdeveloped, for which the driven-round-up hunting was not effective enough - many ungulates of the plain and mountainous landscapes were difficult to get with a spear.

A cardinal way out of this ecological crisis was found by the Neolithic revolution.

Mesolithic

The Paleolithic, about 15 thousand years ago, began to gradually give way to the Mesolithic. The invention of the bow and arrow in the Mesolithic contributed to the expansion of the number of hunting species, led to the emergence of new forms of hunting using dogs in the corral. In the drawings of the Mesolithic, scenes of battles appear for the first time. Wars have entered the life of mankind.

Did the Mesolithic man knowingly or spontaneously tame the dog? Of course, it is tempting and flattering to think that our ancestors deliberately began to use one of the ancestors of dogs (jackal or wolf?) For hunting. But here, most likely, there was a process of mutual adaptation of man and semi-secret predator to each other. Most likely, predators settled near man's dwellings, near his garbage heaps with food remains, some of which then began to accompany him during hunting. Such a process of transition from a free lifestyle to a synanthropic one can quite quickly occur in animals with such a high level of mental development as canines.

According to the observations of M.V. Geptner, in the Moscow region in the late 1970s. wolves settled near the garbage dumps of one of the poultry farms, feeding on its waste; one pair of wolves set up a den in Vorontsovsky Park within the city of Moscow. Thus, the transition of the dog's ancestors to the synanthropic way of life could be accomplished relatively easily, and this appearance of the synanthropic animal near man became a prerequisite for its further domestication. O high level the development of the rational activity of canines is said by the experiments of L.V. Krushinsky. This researcher, who kept a pack of wolves in the vivarium of Moscow University for a long time, noted the amazing variability of behavioral reactions in wolves in the absence of any selection: “... among European wolves raised from puppyhood among humans, an extremely large polymorphism in the manifestation of and expressions of aggression towards a person. From very aggressive males, who only after long-term work with them can establish unreliable contact with a person, to very affectionate females willingly coming into contact with any stranger, you can see a continuous series of transitions.

The experiments of D.K. Belyaeva and L.N. Tinder to study the effect of selection on the tameness and variability of foxes simulates the process of domestication of the ancestors of dogs and other domestic animals. For 20 years, these Novosibirsk scientists have been selecting foxes by behavior. About 10 thousand animals passed through their hands. About 30% of foxes showed pronounced aggressiveness towards humans, 40% were aggressively cowardly, 20% were cowardly. However, 10% of foxes were not only characterized by exploratory behavior, they were not characterized by either aggressiveness or cowardice, moreover, they were fond of humans.

Belyaev and Trut led the selection in two directions - aggressiveness and tameness. In the offspring of aggressive foxes, variability in color was not observed, the quality of fur remained high for 20 generations, and monoestricity was strictly preserved in them, i.e. strict seasonality of breeding once a year.

The selection of foxes for tameness has led, over several generations, to the emergence of a wide spectrum of variability in other, non-behavioral characteristics: the quality of the fur of tamed foxes has noticeably deteriorated - from a fox it has become like a dog's, piebald and black-backed foxes, foxes with drooping ears, foxes with a tail curled into a ring, like the tail of a husky. Selection for tameness at the same time violated the strict natural control over the seasonality of breeding: foxes from monoestric turned into diestric. This transition from monoestricity to diestricity and polyestricity distinguishes humans from monkeys, domestic animals from their wild ancestors.

Unconscious selection for tameness, feeding removed the press of stabilizing selection that maintains low variability natural populations, and as a result, a wide range of mutations could appear rather quickly in a semi-synanthropic-semi-domestic population of dog ancestors. These mutations then began to be maintained first by unconscious and then by conscious artificial selection.

If the domestication of a dog dates back to the age of 12-14 thousand years, then the association between primitive hunters and wolves, according to experts in the field of domestication, began to appear at least 40 thousand years ago, i.e. in the Upper Paleolithic.

The man who settled along the Oikumen continued to attack nature in the Mesolithic. One of the first victims of coastal settlements of St. Rhytina, or Hydrodamalus stelleri). This largest species of sirens, apparently, had an amphipacific distribution and lived from the north of Hokkaido through the Kuriles and the south of Kamchatka to the Commanders, the Aleutian Islands and along the Pacific coast North America... There are known finds of skulls of this species near San Francisco, dated by radiocarbon to the age of 22,500 and 19,000 years. About 12,000 years ago, he still met in the Aleuts. Immediately after the appearance of the Late Paleolithic and Neolithic Hypericum, the sea cow disappeared. She lived on the Commanders until Bering's expedition in the 18th century. and was completely exterminated by Russian St. John's wort in 27 years. The fact that the sea cow survived on the Commander Islands until the 18th century serves as indirect evidence that the settlement of North America by humans proceeded through the Beringian Bridge, and not across the Commander-Aleutian Ridge, since this unprotected sedentary species could not survive contact with humans.

Neolithic revolution

After the Mesolithic, at different times in different territories, the Neolithic began - the period of making polished stone tools, the invention of drilling in stone, the appearance of an ax (which contributed to the clearing of forests), and later the invention of molding and annealing clay for making dishes. Accordingly, pre-ceramic and ceramic Neolithic are distinguished.

The main event of the Neolithic era was the so-called neolithic revolution - the transition from gathering and hunting to plant growing associated with the emergence of cultivated plants, and animal husbandry associated with the domestication of animals. The Neolithic Revolution first of all began in the Middle East, where the first types of cereals were introduced into the culture - one-grain and two-grain wheat, barley. Here the goat was domesticated and, as our research showed, the ancestors of the sheep were Asian mouflons. First unconscious and then conscious artificial selection began to be applied. The result of the Neolithic revolution was the emergence of agriculture. From the Middle East, agriculture began to spread across the Mediterranean countries and southern Europe and move eastward (Table 1). The strongest anthropogenic pressure arose on pastures and arable lands.

The transition from hunting and gathering to agriculture affected primarily areas with a relatively warm climate, where the previous Late Neolithic and Mesolithic ecological crises led to a sharp decline in hunting resources. Hunting tribes did not disappear, but began to develop more northern regions of Europe and North America that were liberated after the melting of glaciers.

The transition to agriculture and animal husbandry meant sharp increase food resources and allowed the human population to increase during the Neolithic by at least an order of magnitude, i.e. as a result of the Neolithic revolution, the number of humans began to be measured in tens of millions of individuals. So, according to the calculations of the American archaeologist F.K. Howell, the human population by the end of the Neolithic Revolution - 6,000 years ago - was 86.5 million individuals.

To be continued