How many people live on earth. Human settlement of the earth
Anthropogenesis - the process of separating a person from the animal world - went through, according to most researchers, three main stages:
1. time of successive existence of human anthropoid ancestors,
2. ancient people (archanthropes)
3. modern people (neoanthropes).
All people inhabiting the Earth at the present time belong to the species Homo sapiens (homo-man, sapiens-intelligent). The most important features of Homo sapiens are an upright body position and walking on two legs, a very well developed brain and flexible hands. The totality of these traits makes it possible for man to use the environment to feed and clothe his entire large population and create amazing civilizations. However, the unceremonious and often hostile treatment of all kinds of living beings (including humans) began to turn against us. We are belatedly beginning to realize that our planet is a closed ecosystem with limited space and limited energy supplies, and that we are consuming and destroying its resources faster than nature can replenish them. According to some scientists, we simply play in nature the role that is destined for us and which we cannot avoid: we change the environment to such an extent that it is no longer able to support our existence, and pave the way for other species (perhaps some insects) who will one day take over the earth. Others believe that we will be able to solve our environmental problems, just as we have dealt with so many other problems.
Human population growth is ultimately at the root of most of our other environmental problems. The population explosion began even when the primitive tribes began to obtain food not by hunting and gathering, but by cultivating the land - a change that had a profound impact on the history of mankind.
human evolution
Homo sapiens is one of the representatives of mammals belonging to the order of primates, to which tupai also belong, tarsiers, lemurs, lorises and monkeys, including great apes.
Order of primates
Lower primates or semi-monkeys (Prosirnii): Tupai, lemurs, lorises, galagos, tarsiers.
Higher primates, or monkeys (Anthropoidea).
New World monkeys, including capuchins, marmosets.
Monkeys of the Old World, including macaques, baboons.
Greater narrow-nosed monkeys (Hominoidea)
Great apes: gibbon, orangutan, gorilla, chimpanzee Humans (Hominidae): Australopithecus (extinct prehuman), Homo erectus, H. neander-thalensis, H. sapiens
Among living primates, various stages of evolution of this group are represented - from animals similar to primitive mammals of the Cretaceous period, to large great apes and a person.
The most characteristic adaptive features of primates are associated with the extremely high development of some departments. nervous system, especially those parts of the brain on which reasonable behavior and the ability of muscles to deft and subtle actions depend. This development of the nervous system is closely related to the arboreal way of life of ancestral primates and many modern forms. An arboreal lifestyle requires dexterity and well-developed sense organs. An animal that has to jump from branch to branch especially needs good eyesight. In most primates, both eyes look ahead and therefore see the same thing; two identical images superimposed on one another create stereoscopic (volumetric) vision.
During the evolution of primates, the facial part of the skull gradually became shorter. This change is probably adaptive, since there is nothing to prevent forward-facing eyes from looking at the world around them. The shortening of the muzzle was accompanied by a shortening of the jaws and the loss of part of the teeth.
On the one hand, in anthropogenesis, the brain skull increases, reflecting an adaptive increase in the mass and volume of the brain, on the other hand, the configuration and structure of the bones of the brain skull change in the direction of autonomization with respect to elimination factors external environment- mainly mechanical effects. This is reflected in the transformations of the cerebral skull that occur after the termination of selection by the volume of the brain, and completely fits into the framework of the theory of shells of revolution. In particular, the supraorbital and occipital ridges in the skulls of archanthropes and paleoanthropes can be considered as a special structure ("support ring") that works in tension ("expansion perception"). The predominant increase in the height of the brain skull and the change in its configuration from the shape of a gently sloping spherical dome to the shape of a dome outlined along half of the ellipsoidal surface occurring in anthropogenesis leads to a decrease in the thrust and the disappearance of the spacer ring, that is, the supraorbital and occipital ridges.
If evolutionary transformations leading to racial and population variability of the human brain skull are associated with adaptation to gradually and constantly acting weak influences that depend on geographical conditions range (insolation intensity, air temperature and humidity, content of chemicals in the soil, geomagnetic field strength), then the evolutionary transformation of the brain skull as a structure that protects the brain from external mechanical influences arises as a result of adaptation to extreme eliminating factors that act panoicumene (trauma ). This is reflected in the transformations of the skull that occur after the cessation of selection by brain size under conditions of constancy of climatic and geographical factors, and indicates the relative independence of the formation of racial (population) and structural features of the brain skull.
Primates have five fingers on all limbs, and usually one finger is at least to some extent opposed to the other four; thanks to this, the animal can grasp and hold a tree branch or food. The fingers end in sensitive pads and are often equipped with flattened nails rather than curved claws like the fingers of other mammals.
In the early stages of primate evolution, some kind of half-ape, resembling a mouse, moved to life in trees. The living relatives of this semi-monkey - tupai - are also very similar to rats or mice. The most evolutionarily advanced representative of the semi-monkeys is the Indonesian tarsier, which lives in trees and leads a nocturnal lifestyle; The tarsier has huge eyes, fully stereoscopic vision, and its fingers are equipped with nails rather than claws. In addition, his upper lip is covered with hair, like in higher primates, and his face is mobile and expressive. In higher primates, facial expressions serve as a means of communication - this reflects the transition to vision as the dominant sense; in most other mammals, the sense of smell is used to exchange information.
Higher primates (monkeys, including apes, and humans) have stereoscopic color vision, a rounded skull, and a relatively large, well-developed brain, thanks to which they are able to learn complex behaviors. Despite the fact that most monkeys use all four limbs when moving, they can sit upright for a long time; in addition, some tree monkeys spend a lot of time in an upright position, when they throw the body from branch to branch, clinging to them with their forelimbs, a mode of locomotion called brachiation. Bipedalism played a huge role in the evolution of anthropoids, as it freed the forelimbs, which allowed them to be used for the manipulation of food, care for young, and various other functions.
There are currently only four genera of great apes: gibbon, orangutan, gorilla, and chimpanzee. They all live in the Old World and, in their structure and behavior, occupy an intermediate position between the rest of the monkeys and hominids (representatives of the human family). The brains of anthropoids are relatively larger than those of other apes; in addition, they do not have a tail, so it is more convenient for them to sit with their back straight. Great apes, like hominids, have a broad chest, but the two groups differ in that the forelimbs and spine are more adapted for brachiation, the lower limbs are specialized, and the fangs and incisors are larger and more powerful than those of hominids. Gorillas and chimpanzees spend a lot of time on the ground; when moving, they rely on their hind limbs and on the knuckles of their forelimbs, which enables them to use the fingers themselves to carry objects such as food or stones.
Over the past few decades, biochemists have developed methods for determining the evolutionary relationship of organisms based on a comparison of the structure of their chromosomes and proteins. Proteins are synthesized in accordance with the "instructions" contained in the genes; the greater the similarity between the proteins in the representatives of two given species, the more similar their genetic maps and the closer the relationship between the species. Human proteins and chimpanzee proteins are 99% similar. These data, as well as similarities in body structure and behavior, allow us to consider chimpanzees as our closest relatives of all living organisms. Biologists do not believe that humans evolved directly from chimpanzees; in their opinion, both species descended from some common ape-like ancestral species that lived several million years ago, and they are separated from each other, probably by several extinct species. The ancestral line leading to gorillas separated from the line of hominids - chimpanzees a little earlier; even earlier, a branch arose that led to orangutans.
Very few areas of study, and among them the search for the fossil remains of our ancestors, have caused so much controversy and created such confusion. Many finds consist of only a few teeth (they are better preserved due to their hardness) and a fragment of the jaw or one of the bones of the leg and several fragments of the skull. Based on such residues, scientists can draw conclusions about the nature of nutrition, the size of the brain and the position of the body. It is easy to imagine how difficult this is; indeed, scholars often disagree about how to interpret this or that feature. Recently, anthropologists have found a number of very important fossils and re-analyzed all available data. This made it possible to partially eliminate ambiguities, but nevertheless left a number of significant gaps.
Since our closest living relatives are the African great apes, the search for a putative common ancestor of these apes and humans has been conducted mainly in Africa. In the Miocene (25-13 million years ago), many wooded areas turned into open steppes. Apparently, during this period, some ape-like forms emerged from the forests; one possible hominid ancestor from the Miocene deposits of Africa and Asia showed a tendency to walk on two legs.
According to anthropologists, hominids diverged from the great apes between 10 and 4 million years ago, but we have almost no fossils of hominin ancestors from this period.
The scientific data accumulated at the present time make it possible to consider North-East Africa as the "cradle of mankind". The oldest known human ancestors - Ramapithecus - is known only from a few teeth and jaw fragments, the age of which is determined at 9-14 million years ago. It is not known if he was upright.
The initial stages of anthropogenesis began 2.5 - 3 million years ago with the emergence of African Australopithecus (Australopithecus Africanus), which was upright, had a developed brain and made tools. However, some modern experts do not consider any known variety of Australopithecus to be a direct ancestor. modern people, but believes that it was a lateral (dead-end) branch of evolution, and, therefore, archanthropes only had a common ancestor with Australopithecus.
The first undoubted remains of hominids, 4 to 3.5 million years old, were found in Ethiopia and assigned to the genus Australopithecus. An almost complete skeleton of an Australopithecus, nicknamed Lucy, belongs to an adult woman who lived about 3.5 million years ago. During her lifetime, she walked on two legs, i.e. straightening up; her height reached one meter, although the men belonging to the same species were larger. Whether Lucy was entirely terrestrial or spent a significant portion of her time in the trees is a matter of controversy.
The teeth of Australopithecus were very similar to the teeth of modern man (small incisors and fangs); however, large massive jaws and a brain, which was slightly larger than those of living great apes, bring them closer to the latter. Apparently, these hominids collected carrion and hunted.
The later australopithecines were undoubtedly upright and lived on the ground, so that their hands were free and they could catch animals, throw stones and perform other actions. Heaps of animal bones, found along with Australopithecus fossils dating back to about 2.5 million years ago, indicate that meat has become a permanent part of their diet. These hominids also used crude stone tools.
One can only hypothesize that the advantages created by cooperative hunting and group protection may have caused the selection that led to the development of language as a means of communication.
Homo erectus, the species from which modern humans are believed to have descended, appeared about 1.5 million years ago. His jaws, teeth, and brow ridges were still massive, but the brain volume of some individuals was almost the same as modern man. Some bones of N. erectus are found in caves; this suggests that he had a more or less permanent dwelling. In addition to animal bones and rather well-made stone tools, heaps of charcoal and burnt bones were found in some caves, so that, apparently, at this time Australopithecus had already learned how to make fire. It is possible that this custom arose as a result of the use of natural fire in order to keep warm or cook food, as well as to split stones.
This stage of hominin evolution correlates with the colonization of other colder regions by Africans. It would be impossible to survive the cold winters without developing complex behaviors or technical skills. Apparently the prehuman brain of Homo erectus was able to find social and technical solutions (fire, clothing, food storage, and living together in caves) problems associated with the need to survive in the winter cold.
The selection pressures that conditioned the evolution of the most prominent human feature, the large brain, are still unclear and widely debated. This discussion is hampered by the fact that scientists have not come to a consensus on the question of what is the relationship between the size of the brain and the development of the hands, on the one hand, and intelligent behavior, on the other. We still have not studied our own brains well enough, not to mention the brains of ancient hominids left in the distant past, and therefore we can only speculate about when and under what selection pressures certain changes occurred.
The improvement of tools and the development of man led to the next period of anthropogenesis, represented by modern people (Homo sapiens). The modern human species includes only two subspecies: Neanderthals (Homo sapiens neanderthalensis), which appeared 250-200 thousand years ago, and people of modern morphological appearance (Homo sapiens sapiens), which appeared about 40-35 thousand years ago.
Neanderthals lived 250-40 thousand years ago during the Ice Age. These people were widely distributed over the earth, lived in different climatic and natural conditions and were divided anthropologically into different groups, but these groups do not correspond to modern races. Previously, scientists assumed that people of the modern type originated from one of the groups of Neanderthals in the subsequent era. Now Neanderthals are considered as a kind of side branch of Homo sapiens. In the Don and the North Caucasus, the appearance of people is associated precisely with the Neanderthals.
The transition of human society to the Upper Paleolithic
The birthplace of modern mankind was most likely Western Asia with adjacent areas. About 20 thousand years ago, modern people spread widely across Europe, Asia and Africa. Cro-Magnons developed articulate speech, fine arts appeared. At this time, the material culture of primitive man changed significantly - stone processing technology reached a high level, horn and bone were widely used, a new form of organization of human society, the clan, replaced the primitive herd.
The Neanderthal man, whose brain was the same size as that of modern humans, but whose skull was still heavy, is sometimes referred to as Homo sapiens. Neanderthals appeared about 100,000 years ago. The remains of a completely modern representative of N. sapiens were first discovered in sediments 40,000 years old.
Neanderthals are paleoanthropes, they stand much closer to modern man than the archanthropes that preceded them. Neanderthals spread very widely. Their parking lots on the territory of our country were found in the Caucasus, in the Crimea, in Central Asia, Kazakhstan, in the lower reaches of the Dnieper and Don, near Volgograd. Glaciation, which changed the composition of animals and the appearance of flora, began to play an important role in the development of man. Neanderthals learned how to make fire, which was a huge conquest of the emerging humanity. Apparently, they already had the first rudiments of ideological ideas. In the Teshik-Tash cave in Uzbekistan, the deceased was surrounded by the horns of a mountain goat. There are burials in which the bodies of the dead are oriented along an east-west line.
For many years, the question was discussed, where is the place of Neanderthals on the evolutionary tree and whether interbreeding between them and Homo sapiens during their coexistence for tens of millennia. If crossing was possible, then modern Europeans might have some Neanderthal genes. The answer - although not definitive - was obtained quite recently in the study of Neanderthal DNA. Geneticist Svante Pebo - the same one who studied DNA from Egyptian mummies, extracted DNA from the remains of a Neanderthal man, having an age of several tens of thousands of years. Despite the fact that the DNA was highly fragmented, scientists were able to use the most modern method of DNA analysis - the polymerase chain reaction (PCR) method - to establish the nucleotide sequence of a small section of mitochondrial DNA. Mitochondrial DNA was chosen for research because its molar concentration in cells is hundreds of times higher than the concentration of nuclear DNA.
DNA extraction was carried out under conditions of the highest sterility - scientists worked in suits resembling spacesuits in order to prevent accidental contamination of the studied samples with foreign, modern DNA. Under normal conditions, using the polymerase chain reaction method used by scientists, it is possible to “read” DNA fragments up to several thousand base pairs long. On the studied samples, the maximum length of the “read” fragments was about 20 base pairs.
Having received a set of such short fragments, the scientists restored the original nucleotide sequence of mitochondrial DNA from them. Comparing it with the DNA of a modern person showed that they are significantly different. The data obtained suggest that Neanderthals constituted a separate, albeit related, species.
Most likely, the crossing of these two species was impossible - the genetic differences between them are too great. Therefore, there are no genes derived from Neanderthals in the human gene pool. According to the DNA sequence, the time of the divergence of the branches of the Neanderthal and modern man was estimated, which amounted to 550-690 thousand years.
In the late Paleolithic (40-35 thousand years ago), a person of the modern type (Cro-Magnon man) was formed. These people have already significantly improved the technique of making stone tools: they are becoming much more diverse, sometimes miniature. A throwing spear appears, which greatly increased the efficiency of hunting. Art is born. Rock art served magical purposes. Images of rhinos, mammoths, horses, etc. were applied to the walls of the caves with a mixture of natural ocher and animal glue. (for example, Kapova cave in Bashkiria). In the Paleolithic era, the forms of human communities also gradually change. From the primitive human herd - to the tribal system, which arises in the late Paleolithic.
The tribal community, which is characterized by common ownership of the main means of production, becomes the main cell of human society. The transition to the Middle Stone Age - the Mesolithic in our territory began in the XII-X millennium BC, and ended in the VII-V millennium BC. During this time, mankind made many discoveries. The most important invention there were bows and arrows, which led to the possibility of not driven, but individual hunting, and for small animals. The first steps were taken in the direction of cattle breeding. The dog was tamed. Some scholars suggest that pigs, goats and sheep were domesticated at the end of the Mesolithic. Cattle breeding as a type of economic activity was formed only in the Neolithic, when agriculture was also born. The transition to a productive economy is of such extraordinary importance for humanity and, in terms of the Stone Age, occurred so quickly that scientists can even speak of a Neolithic "revolution".
The range of stone tools is expanding and improving, but fundamentally new materials are also appearing.
So, in the Neolithic, the manufacture of ceramics was mastered, still stucco, without a potter's wheel. Weaving was also mastered. The boat was invented and shipping began. In the Neolithic, the tribal system reaches a higher stage of development - large associations of clans are created - tribes, intertribal exchange and intertribal ties appear.
Image copyright Thinkstock
Does the Earth have enough resources to support a rapidly growing human population? Now it is over 7 billion. What is the maximum number of inhabitants, above which the sustainable development of our planet will no longer be possible? The correspondent undertook to find out what the researchers think about this.
Overpopulation. At this word, modern politicians wince; in discussions about the future of planet Earth, he is often referred to as the "elephant in the room."
Often, a growing population is spoken of as the biggest threat to the existence of the Earth. But is it right to consider this problem in isolation from other contemporary global challenges? And is it really so threateningly many people live on our planet now?
- What do giant cities suffer from?
- Seva Novgorodtsev about overpopulation of the Earth
- Obesity is more dangerous than overcrowding
It is clear that the Earth does not increase in size. Its space is limited, and the resources necessary to sustain life are finite. Food, water and energy may simply not be enough for everyone.
It turns out that demographic growth is a real threat to the well-being of our planet? Not at all necessary.
Image copyright Thinkstock Image caption The earth is not rubber!"The problem is not the number of people living on the planet, but the number of consumers and the scale and nature of consumption," says David Satterthwaite, senior researcher at the London International Institute on environmental and development issues.
In support of his thesis, he cites a consonant statement by the Indian leader Mahatma Gandhi, who believed that "there are enough [resources] in the world to satisfy the needs of every person, but not universal greed."
The global effect of a multi-billion increase in urban population could be much smaller than we think
Until recently, the number of representatives of the modern human species (Homo sapiens) living on Earth was relatively small. Just 10 thousand years ago, no more than a few million people lived on our planet.
It wasn't until the early 1800s that the human population reached a billion. And two billion - only in the 20s of the twentieth century.
Currently, the world's population is over 7.3 billion people. According to UN forecasts, by 2050 it could reach 9.7 billion, and by 2100 it is expected to exceed 11 billion.
Population has only begun to grow rapidly in the last few decades, so we do not yet have historical examples on which to base our predictions about possible consequences this growth in the future.
In other words, if it is true that more than 11 billion people will live on our planet by the end of the century, our current level of knowledge does not allow us to say whether sustainable development is possible with such a population - simply because there has not yet been precedents in history.
However, we can get a better picture of the future if we analyze where the most significant population growth is expected in the coming years.
The problem is not the number of people living on Earth, but the number of consumers and the scale and nature of their consumption of non-renewable resources
David Satterthwaite says that most of the demographic growth in the next two decades will occur in the megacities of those countries where the level of income of the population at the current stage is assessed as low or medium.
At first glance, an increase in the number of inhabitants of such cities, even if by several billion, should not have serious consequences on a global scale. This is due to historically low levels of urban consumption in low- and middle-income countries.
Emissions of carbon dioxide (CO2) and other greenhouse gases are a good indication of how high a city's consumption can be. "About cities in low-income countries, we know that carbon dioxide ( carbon dioxide) and its equivalents are less than a tonne per person per year, says David Satterthveit. - In countries with high level income values of this indicator range from 6 to 30 tons.
Residents of more economically prosperous countries pollute the environment to a much greater extent than people living in poor countries.
Image copyright Thinkstock Image caption Copenhagen: high standard of living, but low greenhouse gas emissionsHowever, there are exceptions. Copenhagen is the capital of Denmark, a high-income country, while Porto Allegre is in Brazil, an upper-middle income country. Both cities have a high standard of living, but emissions (on a per capita basis) are relatively low in volume.
According to the scientist, if we look at the lifestyle of one single person, the difference between rich and poor categories of the population will be even more significant.
There are many low-income urban dwellers whose consumption is so low that it has little to no effect on greenhouse gas emissions.
When the world's population reaches 11 billion additional load on its resources may be relatively small.
However, the world is changing. And it's entirely possible that low-income megacities will see carbon emissions rise soon.
Image copyright Thinkstock Image caption People living in high-income countries should do their part to save sustainable development Lands with a growing populationThere is also concern about the desire of people in poor countries to live and consume at levels that are now considered normal for high-income countries (many would say that this would be some kind of restoration of social justice).
But in this case, the growth of the urban population will bring with it a more serious burden on the environment.
Will Steffen, Professor Emeritus, Fenner School environment and society at State University Australia, says this is in line with a general trend that has emerged over the past century.
According to him, the problem is not population growth, but the growth - even more rapid - of world consumption (which, of course, is unevenly distributed around the world).
If so, then humanity may find itself in an even more predicament.
People living in high-income countries must do their part to keep the Earth sustainable with a growing population.
Only if richer communities are willing to reduce their consumption levels and allow their governments to support unpopular measures can the world as a whole reduce the negative human impact on the global climate and more effectively address issues such as resource conservation and recycling.
In a 2015 study, the Journal of Industrial Ecology tried to look at environmental problems from the point of view of the household, where the focus is on consumption.
If we adopt smarter consumer habits, the state of the environment can improve dramatically
The study showed that private consumers account for more than 60% of greenhouse gas emissions, and in the use of land, water and other raw materials, their share is up to 80%.
Moreover, the researchers concluded that the pressure on the environment differs from region to region and that, per household, it is highest in economically prosperous countries.
Diana Ivanova of the University of Science and Technology in Trondheim, Norway, who developed the concept for this study, explains that it changes the traditional view of who should be responsible for industrial emissions associated with the production of consumer goods.
"We are all trying to shift the blame to someone else, to the state or to enterprises," she notes.
In the West, for example, consumers often express the opinion that China and other countries that produce consumer goods in industrial quantities should also be responsible for emissions associated with production.
Image copyright Thinkstock Image caption Modern society depends on industrial productionBut Diana and her colleagues believe that an equal share of the responsibility lies with the consumers themselves: "If we begin to follow smarter consumer habits, the state of the environment can significantly improve." According to this logic, radical changes are needed in the basic values of developed countries: the emphasis should move from material wealth to a model where the most important thing is personal and social well-being.
But even if favorable changes take place in mass consumer behavior, it is unlikely that our planet will be able to sustain a population of 11 billion people for a long time.
Therefore, Will Steffen proposes to stabilize the population somewhere in the region of nine billion, and then begin to gradually reduce it by reducing the birth rate.
Stabilization of the Earth's population implies both a reduction in resource consumption and the expansion of women's rights.
In fact, there are signs that some stabilization is already underway, even if the population continues to grow statistically.
Population growth has been slowing since the 1960s, and surveys of fertility rates by the United Nations Department of Economic and Social Affairs indicate that, worldwide, the birth rate per woman has fallen from 4.7 children in 1970-75 to 2.6 in 2005-10.
However, in order for some really significant changes in this area, it will take centuries, says Corey Bradshaw of the University of Adelaide in Australia.
The trend towards an increase in the birth rate is so deeply rooted that even major disaster will not be able to radically change the situation, the scientist believes.
According to a 2014 study, Corey concluded that even if the world's population were reduced by two billion tomorrow due to increased mortality, or if governments of all countries, like China, passed unpopular laws that limit the number of children, then by 2100 the number of people on our planet would at best remain at its current level.
Therefore, it is necessary to search alternative ways reduction in the birth rate, and seek urgently.
If some of us, or all of us, increase consumption, then upper limit for an acceptable (from the point of view of sustainable development) population of the Earth
One relatively simple way is to raise the status of women, especially in terms of their educational and employment opportunities, says Will Steffen.
The United Nations Population Fund (UNFPA) estimated that 350 million women in the poorest countries were not going to have their last child, but they had no way to prevent unwanted pregnancies.
If the basic needs of these women in terms of personal development, the problem of overpopulation of the Earth due to excessively high birth rates would not be so acute.
Following this logic, the stabilization of the population of our planet implies both a reduction in resource consumption and the expansion of women's rights.
But if a population of 11 billion is unsustainable, how many people - in theory - can our Earth support?
Corey Bradshaw thinks it's nearly impossible to give a specific number as it will depend on technology in areas such as Agriculture, energy and transport, as well as how many people we are ready to sentence to a life full of hardships and restrictions, including in food.
Image copyright Thinkstock Image caption Slums in the Indian city of Mumbai (Bombay)It is a fairly common belief that humanity has already exceeded the permissible limit, given the wasteful lifestyle that many of its representatives lead and which they are unlikely to want to give up.
As arguments in favor of this point of view, such environmental trends as global warming, the reduction of biospecies diversity and pollution of the world's oceans are given.
Social statistics also come to the rescue, according to which currently one billion people in the world are actually starving, and another billion suffer from chronic malnutrition.
At the beginning of the 20th century, the problem of population was associated equally with female fertility and soil fertility.
The most common option is 8 billion, i.e. a little more than the current level. The lowest figure is 2 billion. The highest is 1024 billion.
And since assumptions about the allowable demographic maximum depend on a number of assumptions, it is difficult to say which of the above estimates is closest to reality.
But ultimately the determining factor will be how society organizes its consumption.
If some of us - or all of us - increase our consumption, then the upper limit on the acceptable (in terms of sustainable development) population of the Earth will decrease.
If we find opportunities to consume less, ideally without giving up the benefits of civilization, then our planet will be able to support more people.
The acceptable population limit will also depend on the development of technology, an area in which it is difficult to predict anything.
At the beginning of the twentieth century, the problem of population was associated equally with both female fertility and the fertility of agricultural land.
In his 1928 book The Shadow of the World to Come, George Knibbs suggested that if the world's population reaches 7.8 billion, humanity will need to be much more efficient in cultivating and using land.
Image copyright Thinkstock Image caption With the invention of chemical fertilizers began a rapid population growthAnd three years later, Carl Bosch received Nobel Prize for his contribution to the development of chemical fertilizers, the production of which was, presumably, the most important factor in the population boom that occurred in the twentieth century.
In the distant future scientific and technical progress can significantly raise the upper limit of the permissible population of the Earth.
Ever since people first traveled into space, mankind is no longer content with observing stars from the Earth, but is seriously discussing the possibility of resettlement to other planets.
Many prominent scientists and thinkers, including the physicist Stephen Hawking, even declare that the colonization of other worlds will have crucial for the survival of man and other biological species represented on Earth.
Although the NASA exoplanet program launched in 2009 discovered a large number of Earth-like planets, they are all too distant from us and little studied. (As part of this program, the American space agency created the Kepler satellite equipped with an ultrasensitive photometer to search for Earth-like planets beyond solar system so-called exoplanets.)
Image copyright Thinkstock Image caption The earth is our only home and we need to learn how to live in it in a sustainable waySo moving people to another planet is not yet an option. For the foreseeable future, the Earth will be our only home, and we must learn to live in it in an environmentally friendly way.
This implies, of course, an overall reduction in consumption, in particular a transition to a lifestyle with low CO2 emissions, as well as an improvement in the status of women around the world.
Only by taking some steps in this direction, we will be able to roughly calculate how much the planet Earth can support the people.
- Read on English language can be on the website.
Humanity has two character traits: poor memory and overconfidence. From an evolutionary standpoint, these qualities give us a survival advantage.
And perhaps it is these qualities that lead us to forget that we are not the first inhabitants of the Earth, and man was not always the same as he is now. For hundreds of thousands of years, the species "people" inhabits our planet, and its representatives are continuously and imperceptibly changing, adapting to the requirements of the environment.
How we would like to look into the future with at least one eye to see who all these gadgets, devices, cozy warm houses that our ancestors could not dream of, endless stresses and anxieties of our complex life will turn people into. modern world… What will they be like - the people of the future? Unknown. But we know what they were!
We offer you to see a selection of reconstructions of appearance various kinds dead people. There are a dozen and a half of them in this list - that's how much is known to science at the moment.
Handy man / Homo habilis
The first member of the genus Homo. They lived 2.6-2.5 million years ago.
Rudolf Man / Homo rudolfensis
A type of people representing (according to traditional ideas) a transitional stage from a skilled person to erectus. They lived 2.0-1.78 million years ago.
Man working / Homo ergaster
Fossil human species that appeared in Africa 1.8 million years ago as a result of the evolution of Homo habilis or Homo rudolfensis.
Homo erectus / Homo erectus
A fossil species of humans considered to be the immediate ancestor of modern humans.
Floresian Man / Homo floresiensis
A dwarf fossil species of humans. They are also called "hobbits" by analogy with the creatures invented by J. R. R. Tolkien.
Predecessor Man / Homo antecessor
A fossil species of people that existed in the period from 1.2 million to 800 thousand years ago. Homo antecessor is considered the most ancient hominid in Europe.
Heidelberg Man / Homo heidelbergensis
The European variety of Homo erectus, who lived in Europe 800-345 thousand years ago.
Rhodesian Man / Homo rhodesiensis
Ceprano Man / Homo cepranensis
The most probable age of the "man from Ceprano" is 450,000 years.
Georgian Man / Homo georgicus
A form of hominids whose remains were found on the territory of Georgia.
Denisov man
Even 40 thousand years ago, the Denisovans inhabited an area that intersects in time and place with territories in Asia where Neanderthals and modern people lived.
Neanderthal / Homo neanderthalensis
The last Neanderthals lived 25-30 thousand years ago.
Cro-Magnons
They appeared much later than the Neanderthals and coexisted with them for some time (40-30 thousand years ago).
Homo sapiens idaltu Homo sapiens idaltu
The approximate age of the find is from 154 to 160 thousand years.
From many other planets - the presence of intelligent beings on it - people. Where and when did the first man appear? People have been searching for an answer to this question for a very long time.
Human settlement of the earth
In the resettlement of people on the planet, two stages are distinguished. Approximately 2 million years ago, ancient people began to penetrate from other areas and to other continents. This stage of the development of the Earth ended approximately 500 thousand years ago. Subsequently, the ancient people died out.
Modern man ("homo sapiens") appeared only about 200 thousand years ago. It was from here that the second stage of human settlement began. First of all, concern for food made them go to new unexplored lands. With an increase in the number of people, the territories on which hunting was carried out expanded, and edible plants were collected. The strong ones also contributed to the resettlement of people. The level of 15-16 thousand years ago was 130 m lower than the modern level, so there were "land bridges" between individual continents and islands. The transition to a settled way of life occurred 11 thousand years ago. This contributed to the development of ancient civilizations. Many monuments of their culture have survived to this day.
Races
The long existence of people in various natural conditions led to the emergence of races - large groups people who have common, inherited, external signs. By outward signs all mankind is divided into four great geographical races.
Negroid race formed in hot regions of the Earth. Dark, almost black, skin, coarse curly or wavy black hair, characteristic of these people, protect against sunburn and overheating of the body. Brown eyes. A wide, flat nose and thick lips help regulate body temperature.
australoid race according to the external signs of its representatives, it is close to Negroid.
Mongoloid adapted to life in and where summer temperatures are high, strong winds and dust storms are frequent. Yellow protects skin from excessive exposure to sunlight. The narrow slit of the eyes saves them from wind and dust. Mongoloids have straight, coarse hair, a large flattened face, prominent cheekbones, and a slightly protruding nose.
Caucasian race divided into northern and southern branches. Southern Caucasians have swarthy skin, brown eyes, and dark hair. The northern ones have white skin, light and soft hair, blue or gray eyes.
Mixed races. Over time, the proportion of people on Earth is growing, in the form of which there are signs of different races. They form mixed races, the emergence of which is associated with the migration of people. These include mestizos - the descendants of Europeans and Indians; mulattos - descendants of Europeans and peoples of the Negroid race; sambo - descendants of Indians and peoples of the Negroid race; Malagasy - the descendants of the peoples of the Negroid and.
0 Man's place in wildlife. Signs and properties of Homo sapiens, allowing to attribute it to various systematic groups of the animal kingdom.
North Kazakhstan region, Akzhar district
Talshyk secondary school
Biology teacher
Ashenova Aina Gumarovna
Biology lesson in grade 11
Man's place in nature. Signs and properties of Homo sapiens, allowing to attribute it to various systematic
groups of the animal kingdom.
Tasks:- To introduce students to the history of studying the problem of human origin, to show the leading role of the teachings of Darwin and Engels in its solution
Continue the formation of skills to compare, analyze, draw conclusions
Raising a love for the animal world
Lesson type: lesson of studying and primary consolidation of new knowledge.
During the classes:
1. Introductory motivational part. Psychological attitude to the lesson.
Stand with your feet shoulder-width apart, arms freely lowered along the torso. Close your eyes. Imagine that you are a tree: a strong mighty oak or a slender thin birch.
Your roots are strong and stable, they go firmly into the ground, and you feel confident and calm.
The trunk is smooth and flexible, it sways slightly, but does not break. Branches freely "sway" along the trunk. The leaves easily "rustle", slightly touching each other.
Your crown is clean and fresh. You are a beautiful powerful tree, you are confident and calm. You are kind, calm and successful.
Now let's all open our eyes, sit quietly and continue our work.
2. Biological dictation:
No. 1. Replace the dots with the appropriate answers.
1.Theory about the origin of man-…. (anthropogenesis)
2. Homo sapiens is one of the representatives of the class of mammals belonging to the order ... (primates)
3. Great apes include ... (gorilla, chimpanzee, orangutan, gibbon)
4. All the people who inhabit the Earth at the present time belong to the species ... (A reasonable person)
5. A single appearance in a person of signs of ancestors - ... (atavism)
6. Speech, thinking, work are among the factors ... (social)
7. Hereditary variability, struggle for existence, natural selection are ... factors (biological)
8. The human race originated from ... (driopithecus)
9. Historically established groups of people, characterized by a common hereditary physical features, -… (race)
10. Early representatives of the species Homo sapiens (Homo sapiens) - ... (Neanderthals)
11. The science of races, their origin and development - ... (racial science)
12. The presence of rudiments and atavisms in a person indicates the origin of a person from ... (animals)
13. The first evidence of the origin of man from animals was presented by ... (J.B. Lamarck)
14. The work “The role of labor in the process of turning a monkey into a man” was written by ... (F. Engels)
15. The organ and product of labor is - ... (hand)
16. The first tools were able to produce - ... (Australopithecines)
17. The time of the appearance of modern man is ... (35 thousand years ago)
18. The first hearths and dwellings were built ... (paleoanthropes)
19. The chin protrusion is developed in ... (neoanthropes)
20. Humanity forms three large races: ... (Caucasoid, Mongoloid, Negroid)
3. Learning new material:
“There is no limit to the human mind, and the world may witness new remarkable discoveries in the coming years or decades,” the natural question will be: how did a species with such a mind arise?
We will try to answer this question over the course of several lessons.
We will argue, assume, refute, make assumptions, etc.
Think, please, what are the objectives of today's lesson? Students making assumptions about what they are learning this topic come to conclusions.
Conclusion: That man is the crowning achievement of nature. What position does he occupy among its vast diversity?
The place of man in the system of the organic world:
Cellular |
|
Superkingdom |
|
Sub-kingdom |
Animals |
Multicellular |
|
chordates |
|
Vertebrates |
|
mammals |
|
Suborder |
|
Family |
narrow-nosed monkeys |
Humans (Hominids) |
|
Homo sapiens Homo sapiens |
Why does a person treat animals, what served as the basis for this hypothesis?
What traits do we have in common with animals
- Disputes about the origin of man do not stop for centuries. This is one of the most intriguing chapters in the evolution of life on Earth.
Man is a representative of the class of mammals, he is a vertebrate animal and therefore is related to fish, amphibians, reptiles and birds.
Table "The main features of the human body inherited from animals"
Main features |
From whom are they inherited |
The genetic code of the nucleus |
The first single-celled eukaryotes |
The genetic code of mitochondria |
First prokaryotes |
Bilateral body symmetry |
Ancestors of early chordates |
Skeleton |
|
Five-fingered limbs |
Fish, amphibians |
Pulmonary respiration |
Amphibians and reptiles |
amniotic egg |
reptiles |
Elongated limbs, tooth differentiation, mammary glands, warm-bloodedness |
primitive mammals |
placenta, live birth |
Early placental mammals |
To date, several hypotheses or theories of the origin of man are being discussed.
- Which of them can you name yourself?
What evidence of origin between man and animals.
Physiological - the fundamental similarity of the processes occurring in human and animal organisms;
Embryological - similar stages of embryonic development in both humans and animals;
Paleontological - finds of the remains of ancient humanoid creatures;
Biochemical - resemblance chemical composition intracellular environment in humans and animals;
Comparative - anatomical - a single plan for the structure of the bodies of humans and animals, the presence of rudiments and atavisms in humans;
genetic - cxaboutdstvo number of chromosomes in humans and great apes.
Conducting a physical minute
4.Doing independent work:
1. What are the similar signs of humans and animals?
2. What features distinguish humans from great apes?
3. Give a description of the position of a person in the system of the animal world.
5. Dividing children into 2 groups. Poster work.
Card work:
A) what are the main results of human evolution, which led to the emergence of significant differences from modern anthropoid apes, why cannot modern apes be considered human ancestors?
b) Describe the variety of great apes.
(All three general biology textbooks are used.)
6. Summing up the lesson:
“What was main idea lesson?”
Find evidence that the origin of man was connected with the evolution of ancient great apes;
What are their family ties?
7.Reflection:- What is your mood at the end of the lesson?
Have you learned something new and interesting?
In what form would you take this lesson?
What did you like about the lesson and what didn't you like?
8. Homework:§30, prepare a crossword on the topic.