Names 

For the first time, ancient art appeared among the Australopithecus. From Australopithecus to a reasonable person. Alternative points of view of the theory of evolution

Australopithecus lived in Pliocene from about 4 million years ago to less than a million years ago. On the time scale, 3 long epochs of the main species are clearly traced, approximately one million years per species. Most species of Australopithecus were omnivorous, but there were subspecies that specialized in plant foods. The ancestor of the main species was most likely anamensis, and the first main species known from this moment became the species afarensis, which existed for about 1 million years. Apparently, these creatures were nothing more than monkeys, moving like a human on two legs, albeit hunched over. Perhaps, in the end, they knew how to use improvised stones to crack, for example, nuts. It is believed that afarensis eventually split into two subspecies: the first branch went to humanization and Homo habilis, the second continued to improve in Australopithecus, forming the new kind Africanus. africanus had slightly less developed limbs than afarensis, but they learned to use improvised stones, sticks and sharp fragments of bones and, in turn, after another million years formed two new higher and last known subspecies of australopithecines boisei and robustus, which survived up to 900 thousand years BC. e. and already could independently produce the simplest bone and wooden tools. Despite this, most Australopithecus were part of the food chain of more progressive people who overtook them in development along other branches of evolution, and with whom they intersected in time, although the duration of their coexistence indicates that there were periods of peaceful coexistence.

From point of view taxonomies Australopithecus belongs to the family hominid(including also of people and modern large great apes). The question of whether any Australopithecus were the ancestors of humans, or whether they represent a "sister" group in relation to humans, has not been fully clarified.

Anatomy

Female skull Australopithecus africanus

FROM human australopithecines brings together underdevelopment jaws, lack of large protruding fangs, prehensile hand with developed thumb, supporting foot and the structure of the pelvis, adapted for upright walking. Brain relatively large (530 cm³), but not much different in structure from the brain of modern great apes. In terms of volume, it was no more than 35% of the average brain size. modern man. The dimensions of the body were also small, no more than 120-140 cm in height, the physique was slender. It is assumed that the difference in size between male and female Australopithecus was greater than that of modern hominins. For example, at modern people men are on average only 15% larger than women, while in Australopithecus they could be 50% taller and heavier, which gives rise to discussions about the fundamental possibility of such a strong sexual dimorphism in this genus of hominids. One of the main characteristic features for Paranthropus is a bony arrow-shaped crest on the skull, which is inherent in males of modern gorillas, therefore it cannot be completely excluded that the robuster / Paranthropic forms of Australopithecus are males, and the gracile ones are females, an alternative explanation may be the assignment of forms different sizes to different types or subspecies.

Development of forms within the genus

The main candidate for the place of the ancestor of Australopithecus is the genus Ardipithecus. At the same time, the oldest of the representatives of the new genus, Australopithecus anamensis, descended directly from Ardipithecus ramidus 4.4-4.1 million years ago, and 3.6 million years ago gave rise to Australopithecus afarensis to which the famous Lucy. With the discovery in 1985 of the so-called "black skull", which was very similar to Paranthropus boisei, with a characteristic bone crest, but at the same time was 2.5 million older, official uncertainty appeared in the Australopithecus pedigree, because although the results of the analyzes may vary greatly depending on many circumstances and the environment where the skull was located, and, as usual, will be rechecked dozens of times for decades, but at the moment it turns out that Paranthropus boisei could not have descended from Australopithecus africanus, since he lived before them, and at least lived at the same time as Australopithecus afarensis, and, accordingly, could not have descended from them either, unless, of course, the hypothesis that parathropic forms of Australopithecus and Australopithecus are males and females of the same species is taken into account.

Known forms

Previously, three more representatives were assigned to the genus Australopithecus, but at present it is customary to distinguish them in a special genus. paranthropes (Paranthropus).

Place in evolution hominid

Reconstruction of a female Australopithecus afarensis

Genus Australopithecus considered to be the ancestor of at least two groups of hominids: paranthropes And of people. Although Australopithecus did not differ much from monkeys in terms of intelligence, they were upright, while most monkeys are quadrupedal. Thus, bipedalism preceded the development of intelligence in humans, and not vice versa, as previously assumed.

How Australopithecus moved to upright posture is not yet clear. Reasons considered include the need to grasp objects such as food and babies with the front paws and scan the surroundings over tall grass for food or to spot danger in time. It has also been suggested that the common ancestors of upright hominids (including humans and australopithecines) lived in shallow water and fed on small aquatic life, and bipedalism was formed as an adaptation to movement in shallow water. This version is supported by a number of anatomical, physiological and ethological features, in particular, the ability of people to arbitrarily hold their breath, which not all swimming animals are capable of.
According to genetic data, signs of upright walking appeared in some extinct species of monkeys about 6 million years ago, in the era of divergence between people and chimpanzee. This means that not only the Australopithecus themselves, but also the species that was their ancestor, for example, ardipithecus, could already be upright. Perhaps upright walking was an element of adaptation to life in the trees. Modern orangutans use all four paws to move only along thick branches, while thinner branches are either clinging from below or walking along them on their hind legs, preparing to cling to other higher branches with their front legs or balancing for stability. This tactic allows them to get close to fruits that are far from the trunk, or jump from one tree to another. Climate change that occurred 11-12 million years ago led to a reduction in forest tracts in Africa and the emergence of large open spaces, which could push the ancestors of Australopithecus to move to upright walking on the ground. In contrast, the ancestors of modern

general information

australopithecines(lat. Australopithecus, from lat. "australis" - "southern" and other Greek. "Pitekos" - "monkey") - a genus of extinct upright ("two-legged" or bipedal) hominids. Its name is somewhat misleading, because. although it is translated as "southern monkey", in fact the species of this genus are considered to be more progressive than any monkeys. Evidence collected by paleontologists and paleoanthropologists suggests that the genus Australopithecus originated in East Africa about 4.2 million years ago, spread across the continent, and eventually disappeared just under 2 million years ago. Currently, six species of australopithecines that existed during this time are known, the most famous of them are Afar and African.

It is widely believed among archaeologists and paleontologists that Australopithecus played a significant role in human evolution, and that a species of Australopithecus eventually formed the genus Homo (People) in Africa about 2.5 million years ago.

Apparently, Paranthropus or "robust" Australopithecus, which lived simultaneously with early human species, also descended from Australopithecus proper.

History of study

The first discovered and documented find was the skull of an ape-like creature aged about 3-4 years, found in 1924 by workers in a limestone quarry near Taung (South Africa). Raymond Dart, an Australian anatomist and anthropologist who worked at the University of the Witwatersrand in Johannesburg, became interested in the skull. He found that the skull had features similar to those of a human. In particular, the opening for the spinal cord is located below, and not behind as in monkeys, which indicates an upright posture. Dart concluded that these were the remains of an early human precursor (the so-called "missing link") and published his findings in the February 1925 issue of Nature. He named the species he discovered Australopithecus africanus.

Initially, other anthropologists were hostile to the idea that these were the remains of something other than simple apes. Dart's discovery directly contradicted the then prevailing hypothesis that the development of the brain should precede upright posture, all the more so was it confirmed by Piltdown Man. However, in the 1940s, their opinion began to change. And in November 1953, the falsification of the "Piltdown Man" was finally proven.

The first trace of an Australopithecus found in East Africa was a skull belonging to Boyce's paranthropus, which was excavated by Mary Leakey in 1959 in Olduvai Gorge in Tanzania. The Leakey family continued to excavate the gorge, discovering subsequent remains of both Australopithecus, Homo habilis and Homo erectus. Discoveries of the Leakey family in 1959-1961. were a turning point in the recognition of Australopithecus as a link between apes and humans, and Africa as the cradle of mankind.

November 24 (or 30), 1974 Donald Johanson discovered in the Hadar desert (Ethiopia, East Africa) is the most complete Australopithecus ever found, which was named "Lucy" by members of the expedition. The temporal bones, lower jaw, ribs, vertebrae, bones of the arms, legs and pelvis have been preserved - a total of about 40% of the skeleton. In total in 1973-1977. more than 240 different hominid remains have been found, belonging to at least 35 individuals. Based on these findings, the species Australopithecus afarensis was described. In 2000, the skeleton of another young australopithecine of this species was discovered in Ethiopia, most likely belonging to a 3-year-old cub who lived about 3.3 million years ago (the so-called "Lucy's daughter").

Recently, scientists have found the remains of a new species of Australopithecus in South Africa. Fossils of the Australopithecus sediba, which lived about 1.98 million years ago, were discovered in the Malapa cave. Some scientists believe that A. sediba (which in turn evolved from A. africanus) may have evolved into H. erectus.

Origin and evolution

According to the Chimpanzee Genome Project, the human (Ardipithecus, Australopithecus and Homo) and chimpanzee (Pan troglodytes and Pan paniscus) lines, having descended from a common ancestor, separated about 5-6 million years ago (assuming a constant rate of evolution). One theory suggests that although the human and chimpanzee lineages diverged at first, then some populations interbred over a million years after this divergence.

Classification and known species

There is still debate among scholars as to whether certain African hominin species of the time, such as aethiopicus, boisei, and robustus, are members of the genus Australopithecus. If so, then they (according to Western European terminology) can be distinguished into the group of “robust” (from the English “robust” - strong, strong, reliable) Australopithecus, while the rest form a group of “gracil” (from the English. “ gracile" - slender, thin).

And, although the opinions of various scientists regarding the inclusion of "robust" species in the genus Australopithecus differ, the consensus of the scientific community as a whole at the moment is that they should be isolated in separate genus paranthropus. Paranthropus are believed to be further development australopithecines. Morphologically, paranthropes are noticeably different from Australopithecus, and the features of their morphology give reason to believe that they also differed significantly from their ancestors in behavior.

Currently, the remains of about 500 individuals of Australopithecus and Paranthropus are known, which belong to the following species:

Russian name Latin name Alternative and legacy options Period of existence, million years ago
Australopithecus anamanis Australopithecus anamensis 3,9-4,2
Australopithecus afarensis Australopithecus afarensis 2,9-3,9
Australopithecus Bahr el Ghazal Australopithecus bahrelghazali 3,6
australopithecine africanus Australopithecus africanus Plesianthropus transvaalensis 3,03-2,04
Australopithecus gari Australopithecus garhi 2,6
Australopithecus sediba Australopithecus sediba 1,98
Ethiopian Paranthropus Paranthropus aethiopicus Australopithecus aethiopicus 2,7-2,39
Boyce paranthropus Paranthropus boisei Australopithecus boisei, Zinjanthropus 2,3-1,2
Paranthropus massive (Robustus) Paranthropus robustus Australopithecus robustus 2,0-1,2

Morphology

Common and defining features for all (“gracil” and “robust”) Australopithecus are:

  1. Anatomy adapted for upright walking.
  2. High value of the brachial index (the ratio of the length of the forearm and shoulder).
  3. Sexual dimorphism, more pronounced than in humans and chimpanzees, but weaker than in gorillas.
  4. Height 1.2-1.5 m, weight 29-55 kg (estimated).
  5. The capacity of the skull is 350-600 cm3.
  6. The molars are relatively large with thicker enamel than in humans and modern apes.
  7. Incisors and fangs are relatively small, sexual dimorphism in the structure of canines is less pronounced than in modern monkeys.

Adaptation to upright posture has special meaning in human evolution. All australopithecines have anatomical features skull, spine, pelvis, and legs that promote upright posture. The foramen in the occipital bone is at the bottom of the skull, indicating the angle at which the spinal cord enters. The S-shaped spine helps to maintain balance when walking on two legs and absorbs vibrations. The pelvis is wide and short. The femoral neck lengthens, increasing leverage for the muscles attached to the femur. Hip and knee joints provide the necessary distribution of weight when walking.

The high value of the brachial index suggests that, despite the clear morphological evidence of adaptation to life on the ground, Australopithecus could still use the arboreal habitat. Perhaps they slept in the trees, fed, or escaped from land-based predators.

The degree of sexual dimorphism inherent in Australopithecus is hotly debated. For some skeletal specimens, it is disputed whether the difference in size is due to the manifestation of dimorphism, or the presence of two various kinds. Despite the lack of certainty in the assessment of body size from fossil specimens, it is currently believed that the sexual dimorphism of Australopithecus is markedly more pronounced than that of humans and chimpanzees. Particularly in humans, men more women an average of 15%. At the same time, in Australopithecus, males could be up to 50% heavier than females. However, the dimorphism in the structure of the fangs, which is characteristic of monkeys, is much weaker. The importance of the degree of dimorphism is important because social organization and reproduction depend on it.

As already noted, it is very difficult to estimate body size from fragmentary fossil samples. In addition, some species are known from very small sets of fragments, which further complicates the task. However, other species are represented fairly well, and their height and weight can be estimated relatively reliably. In terms of body weight, Australopithecus are comparable to chimpanzees, but due to upright posture they are taller.

The general trend of human evolution is an increase in the volume of the brain, but over the millions of years of the existence of Australopithecus, progress in this direction was very small. The brain volume of most Australopithecus species was approximately 35% of the brain of a modern person. This is only slightly more than that of a chimpanzee. A noticeable increase in the brain volume of primates occurred only with the advent of the genus Homo.

The cognitive abilities of Australopithecus are unknown, but there is evidence that at least some species made and used the simplest stone tools around 2.6 million years ago. Perhaps the tools were made from other materials (for example, wood), but the processes of destruction of organic materials do not allow us to detect them. There was no evidence of Australopithecus proficiency in speech or fire control.

The study of the structure of the teeth is very important, because. isolated teeth are the most common fossils. The study of their structure can be used for phylogenetic relationships, diet and social organization. The molars of Australopithecus are large and have thick enamel (it is especially thick in Paranthropus).

Today, living primates with a similar structure of teeth eat solid plant foods - nuts, seeds, etc. Therefore, it is believed that such food was a significant part of the diet of Australopithecus. In addition, some "gracile" Australopithecus probably also ate the meat and bone marrow of animals killed by predators. To separate meat from bones and extract bone marrow, some of them, according to the results of separate studies, even used primitive stone tools. It is possible that animal food rich in protein and microelements also served as one of the reasons for the increase in the brain and the development of intelligence.

In addition to the features described above, certain types of Australopithecus could have others that bring them closer to humans. These include a developed hand, with a long and strong opposable thumb, a foot with an arch (in contrast to the flat feet of monkeys), etc.

Evolutionary role

The study of the remains shows that Australopithecus is the common ancestor of a separate group of hominids called Paranthropus ("robust" Australopithecus) and most likely the genus Homo, which includes modern humans. A key feature of all these primates is upright posture (“bipedalism” or bipedalism). The morphology of australopithecines refuted the previously widespread opinion that it was the large brain that preceded upright posture.

The earliest evidence of erect walking hominids is from Laetoli, Tanzania. Footprints surprisingly similar to modern human footprints have been found in this area, and dated to about 3.6-3.8 million years ago. It is believed that these are footprints of Australopithecus, because. they are the only human ancestors living there at that time.

Such evidence makes it abundantly clear that the large brain evolved much later than the transition to upright posture. At the same time, the reason for discussions is the question of how and why millions of years ago it appeared at all. Advantages of bipedalism - freeing hands for manipulating objects (carrying food and babies, using and making tools), high level eye (above the grass in the savannah) to see possible food sources or predators. However, many anthropologists believe that these advantages are not sufficient to cause it to appear.

New studies of primate evolution and morphology have shown that all apes (modern and fossil) have a skeletal adaptation to the upright position of the body. Orrorin was already upright about 6 million years ago, during the separation of human and chimpanzee lines (according to the results of genetic studies). This means that walking in an upright position on straight legs originally appeared as an adaptation to a lifestyle in the trees. A study of modern orangutans in Sumatra shows that they use all four limbs when walking on large, stable branches. Under branches of a smaller diameter, they move by clinging to them with their hands, but along flexible thin (less than 4 cm in diameter) branches, they walk on straightened legs, using their hands for balance and additional support. This allows them to get closer to the edge of the forest canopy to forage or move to another tree.

The ancestors of gorillas and chimpanzees became more specialized in climbing up vertical tree trunks using their knees bent, which is consistent with their knuckle-footed way of walking on the ground. This was due to climate change about 11-12 million years ago, which affected forests in Eastern and Central Africa when the treeless spaces that appeared made it impossible to move only along the forest canopy. At this time, the ancestral hominins may have adapted to walking upright for movement on the ground. Man is closely related to these apes, and shares features with them, including carpal bones reinforced for their way of walking.

However, the opinion that human ancestors used this way of walking is now in question, because. the anatomy and biomechanics of such locomotion differ between gorillas and chimpanzees. This means that such a feature arose independently after the separation of the human line. Further comparative analysis suggests that these bone changes arose in order to adapt to moving through trees with the help of hands.

Much reminiscent of the behavior of people, as we have already said. Science also draws evidence in favor of the relationship of man with monkeys from their external and internal structure, embryonic (embryonic) development, and also judges on the basis of the fossil remains of extinct animals. Let's take a look at what they are person's next of kin.

The closest human relatives are monkeys

Unlike other animals, anthropomorphic monkeys, like humans, lack a tail. Once these animals were called four-armed, in contrast to the four-legged lower animals. But this name is wrong. In fact, anthropomorphic monkeys are two-armed and bipedal, which is how they differ from all other animals and are closer to people.
On the fingers and toes, anthropomorphic monkeys (as, indeed, other monkeys) have nails. The palms of their hands are cut with lines very similar to the pattern of human palms. The body of anthropomorphic monkeys is covered with hair, while the human body is free from them. However, in humans, hair scattered throughout the body (especially in men) has been preserved, which is a remnant of the hairline of our monkey ancestors. It is characteristic that even the direction of hair growth on the body is the same higher apes and a person. The auricles of these monkeys, reminiscent of human auricles, attract attention. In the picture: on the left - a chimpanzee, on the right - the artist G. Myrshin, who brilliantly imitated the grimaces of monkeys (photograph 1912). If we turn to the structure of the skeleton, muscles, blood vessels, nerves, brain, respiratory and digestive organs of anthropomorphic monkeys, it turns out that they are surprisingly similar to the same parts of the human body and organs. Rudimentary chest hair in men. Attention is drawn to the similarity in the structure of the mimic (facial) muscles of higher apes and humans. This explains that they are able to express on their faces sensations similar to human ones: fear and calmness, joy and sadness, laughter and crying, etc. On the other hand, due to the similarity in the structure of the mimic muscles of anthropomorphic monkeys and humans, the latter are able to imitate characteristic grimaces of monkeys. By chemical composition the blood of anthropomorphic monkeys is very close to that of humans. They, like people, thirty-two different teeth: incisors, canines, premolars and molars. Great apes gestate in the womb for eight to nine months ( human child within nine months). In the early uterine period of development, the embryo of the great ape cannot be distinguished from the human embryo. Between birth and manhood great apes takes a longer period than in other animals, almost the same as in humans. So, the orangutan reaches maturity at ten or twelve years, and the gorilla - even later. Body parts: Chimpanzee hand and foot, human and gorilla skeleton, human and chimpanzee hand hair growth directions (same), ears (from left to right): chimpanzee, gorilla and human, comparison of human brain (top) and orangutan (bottom). Three stages of development of the embryos of monkeys (left) and humans (right). The listed features far from exhaust the relationship of anthropomorphic monkeys with people. In fact, there are incomparably more of them. Scientists have calculated that the orangutan has more than fifty common features with a person, about ninety for a gorilla, and about a hundred for a chimpanzee. However, modern anthropomorphic apes are not directly related to humans. It helps to reveal our direct relatives paleontology- the science of fossil organisms that have become extinct, not adapting to the changed conditions of life. At the disposal of scientists, a lot of bone remains have accumulated, animals that have long disappeared from the face of the Earth, including the bones of extinct monkeys. Usually these are scattered parts of skeletons and teeth. However, when modern level development of comparative anatomy, even on the basis of scattered bones, it is possible to restore the appearance of the creatures to which these bones belonged. Scientists have long discovered the law of the ratio of parts and organs of animals. It is known, for example, that predatory animals have sharp fangs and claws and that they never have horns and hooves. On the contrary, the feet of all herbivores are equipped with hooves, and almost all ruminants have cloven hooves. Famous comparative anatomist and paleontologist Georges Cuvier(1769–1832), using the law of ratio, he recreated many extinct animal species. Cuvier wrote that it is enough for him to see only the footprint of an animal, and he will not only describe his bodily appearance, but also determine the way of his life. There is an anecdote about Cuvier. Someone, having decided to scare him, made the head of a monstrous animal with horns, put it on himself along with the skin of some animal, and, snapping his teeth, as furious predators usually do, made his way into the room where Cuvier was at night. However, the scientist was not afraid, but burst out laughing and said: I'm not afraid of you monster! You won't eat me because you have horns on your head". There are some other species, the so-called human relatives. In the picture: the oldest fossil monkeys (from left to right): lemur, parapithecus, propliopithecus, dryopithecus and australopithecine. Paleontologists are not only able to restore the appearance of animals on the basis of their bone remains, but also in collaboration with geologists - scientists who study the earth's crust, - also determine the time when these animals lived. Thus, it was established that about fifty million years ago semi-monkeys (lemurs) appeared on Earth, and fifteen million years later the most ancient lower apes(parapithecus). The bone remains of the ancestors of anthropomorphic monkeys (proplyopithecines) were found in the layers of the earth, the antiquity of which is estimated at about thirty million years. Even later, great apes appeared, called driopithecus. They gave rise to modern gorillas and chimpanzees, as well as highly developed fossil anthropomorphic monkeys - Ramapithecus and Australopithecus, directly related to the human ancestry. These are the closest human relatives.

Can apes turn into humans?

Sometimes they ask can they modern monkeys turn into humans and humans into monkeys? Science answers this question in the negative. Everything in nature is constantly changing, evolving, developing. Not only animal species are changing, but also the conditions of their existence - climate, soil, vegetation. As there is nothing immutable in nature, so there are no absolutely identical objects, repeated phenomena and events. Humans and modern anthropomorphic apes, as already noted, once had common ancestors - fossil apes. Modern humans and anthropomorphic apes arose as a result of evolution that took place in different directions and lasted for millions of years in various conditions. During this vast period, humans and anthropomorphic apes have moved far apart. Simultaneously there were changes in all nature. To restore what was millions of years ago is an impossible fantasy. No one can even return yesterday or restore last year's snow. You can't turn an old man into a child again! Such phenomena are told only in fairy tales. One ancient philosopher noticed that you can't step into the same river twice. By this he meant to say that the river flows non-stop and, therefore, is constantly changing. The man has come out of the water and wants to plunge into it again. But for this a short time the river has already managed to change, although imperceptibly to the human eye, and the person himself is no longer the same - he has also changed. All nature, all the life of organisms, can be likened to a river that flows all the time, changes and cannot flow into reverse direction. And people can't start to "reverse evolve" and turn into monkeys. In the same way, modern apes cannot turn into humans.

australopithecines
Australopithecus R. A. Dart, 1925

Kinds
  • † Australopithecus anamanis
  • † Australopithecus afarensis
  • † Australopithecus africanus
  • †Bahr el Ghazal Australopithecus
  • †Australopithecine gari
  • † Australopithecus sediba
Finding places Geochronology
million years Epoch P-d Era
Thu TO
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th
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about
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about
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2,588
5,33 Pliocene H
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about
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23,03 Miocene
33,9 Oligocene P
but
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55,8 Eocene
65,5 Paleocene
251 Mesozoic
◄ Our time ◄ Cretaceous-Paleogene extinction

australopithecines(from lat. australis - southern and other Greek πίθηκος - monkey) - a genus of fossils higher primates, whose bones were first discovered in the Kalahari Desert (South Africa) in 1924, and then in East and Central Africa. They are the ancestors of the genus People.

  • 1 Origins, biology and behavior
  • 2 Anatomy
  • 3 Development of forms within the genus
  • 4 Notable forms
  • 5 Place in hominin evolution
  • 6 See also
  • 7 Notes
  • 8 Links

Origin, biology and behavior

Skull side view
1. Gorilla 2. Australopithecus 3. Homo erectus 4. Neanderthal (La Chapelle-aux-Seine) 5. Steinheim man 6. Modern man

Australopithecus lived during the Pliocene from about 4 million years ago to less than a million years ago. On the time scale, 3 long epochs of the main species are clearly traced, approximately one million years per species. Most species of Australopithecus were omnivorous, but there were subspecies that specialized in plant foods. The ancestor of the main species was most likely the anamensis species, and the first main species known at the moment was the afarensis species, which existed for about 1 million years. Apparently, these creatures were nothing more than monkeys, moving like a human on two legs, albeit hunched over. Perhaps, in the end, they knew how to use improvised stones to crack, for example, nuts. It is believed that afarensis eventually split into two subspecies: the first branch went to humanization and Homo habilis, the second continued to improve in Australopithecus, forming a new species africanus. africanus had slightly less developed limbs than afarensis, but they learned to use improvised stones, sticks and sharp fragments of bones and, in turn, after another million years formed two new higher and last known subspecies of australopithecines boisei and robustus, which survived up to 900 thousand years BC. e. and already could independently produce the simplest bone and wooden tools. Despite this, most Australopithecus were part of the food chain of more progressive people who overtook them in development along other branches of evolution, and with whom they intersected in time, although the duration of their coexistence indicates that there were periods of peaceful coexistence.

Taxonomically, Australopithecus belongs to the hominid family (which also includes humans and modern great apes). The question of whether any Australopithecus were the ancestors of humans, or whether they represent a "sister" group in relation to humans, has not been fully clarified.

Anatomy

Skull of a female Australopithecus africanus

The weak development of the jaws, the absence of large protruding fangs, the prehensile hand with a developed thumb, the supporting foot and the structure of the pelvis, adapted for upright walking, bring Australopithecus closer to man. The brain is relatively large (530 cm³), but differs little in structure from the brain of modern great apes. In terms of volume, it was no more than 35% of the average size of the brain of a modern person. The dimensions of the body were also small, no more than 120-140 cm in height, the physique was slender. It is assumed that the difference in size between male and female Australopithecus was greater than that of modern hominins. For example, in modern humans, men are on average only 15% larger than women, while in Australopithecus they could be 50% taller and heavier, which gives rise to discussions about the fundamental possibility of such a strong sexual dimorphism in this genus of hominids. One of the main characteristic features for Paranthropus is a bony arrow-shaped ridge on the skull, which is inherent in males of modern gorillas, therefore it cannot be completely excluded that the robust / Paranthropic forms of Australopithecus are males, and the gracile forms are females, an alternative explanation may be the assignment of forms of different sizes to different species. or subspecies.

Development of forms within the genus

The main candidate for the ancestor of Australopithecus is the genus Ardipithecus. At the same time, the oldest of the representatives of the new genus, Australopithecus anamensis, descended directly from Ardipithecus ramidus 4.4-4.1 million years ago, and 3.6 million years ago gave rise to Australopithecus afarensis, to which the famous Lucy belongs. With the discovery in 1985 of the so-called "black skull", which was very similar to Paranthropus boisei, with a characteristic bone crest, but at the same time was 2.5 million older, official uncertainty appeared in the Australopithecus pedigree, because although the results of the analyzes may vary greatly depending on many circumstances and the environment where the skull was located, and, as usual, will be rechecked dozens of times for decades, but at the moment it turns out that Paranthropus boisei could not have descended from Australopithecus africanus, since he lived before them, and at least lived at the same time as Australopithecus afarensis, and, accordingly, could not have descended from them either, unless, of course, the hypothesis that parathropic forms of Australopithecus and Australopithecus are males and females of the same species is taken into account.

Known forms

  • Australopithecus afarensis (Australopithecus afarensis)
  • African Australopithecus (Australopithecus africanus)
  • Australopithecus sediba (Australopithecus sediba)
  • Australopithecus prometheus

Previously, three more representatives were assigned to the genus Australopithecus, but at present it is customary to distinguish them in a special genus of Paranthropus (Paranthropus).

  • Ethiopian Paranthropus (Paranthropus aethiopicus)
  • Zinjanthropus (Zinjanthropus boisei, now Paranthropus boisei)
  • Robustus (Australopithecus robustus, now Paranthropus robustus)

Place in hominin evolution

Reconstruction of a female Australopithecus afarensis

The genus Australopithecus is thought to be the ancestor of at least two groups of hominids: Paranthropus and humans. Although Australopithecus did not differ much from monkeys in terms of intelligence, they were upright, while most monkeys are quadrupedal. Thus, bipedalism preceded the development of intelligence in humans, and not vice versa, as previously assumed.

How Australopithecus moved to upright posture is not yet clear. Reasons considered include the need to grasp objects such as food and babies with the front paws and scan the surroundings over tall grass for food or to spot danger in time. It is also suggested that the common ancestors of upright hominids (including humans and australopithecines) lived in shallow water and fed on small aquatic inhabitants, and upright walking was formed as an adaptation to movement in shallow water. This version is supported by a number of anatomical, physiological and ethological features, in particular, the ability of people to arbitrarily hold their breath, which not all swimming animals are capable of.

According to genetic data, signs of upright walking appeared in some extinct species of monkeys about 6 million years ago, during the era of divergence between humans and chimpanzees. This means that not only the Australopithecus themselves, but also the species that was their ancestor, for example, Ardipithecus, could already be upright. Perhaps upright walking was an element of adaptation to life in the trees. Modern orangutans use all four paws to move only along thick branches, while they either cling to thinner branches from below or walk along them on their hind legs, preparing to cling to other higher branches with their front legs or balancing for stability. This tactic allows them to get close to fruits that are far from the trunk, or jump from one tree to another. Climate change that occurred 11-12 million years ago led to a reduction in forest tracts in Africa and the emergence of large open spaces, which could push the ancestors of Australopithecus to move to upright walking on the ground. unlike them, the ancestors of modern chimpanzees and gorillas specialized in climbing vertical trunks and vines, which caused their bow-legged and clubfoot gait on the ground. However, humans have inherited many similarities to these monkeys, including the structure of the bones of the hands, reinforced for walking on the knuckles.

It is also possible that australopithecines were not direct ancestors of humans, but represented a dead end branch of evolution. Such conclusions are prompted, in particular, by the recent finds of Sahelanthropus, an even more ancient great ape, which was more like Homo erectus than Australopithecus. In 2008, a new species of Australopithecus, A. sediba, was discovered that lived in Africa less than two million years ago. Although according to certain morphological features it is closer to people than the more ancient species of Australopithecus, which gave reason to its discoverers to declare it a transitional form from Australopithecus to people, at the same time, apparently, the first representatives of the genus Homo already existed, such as Rudolf man , which rules out the possibility that this species of Australopithecus could have been an ancestor of modern humans.

Most species of Australopithecus used tools no more than modern apes. Chimpanzees and gorillas are known to be able to crack nuts with stones, use sticks to extract termites, and use clubs for hunting. How often Australopithecus hunted is debatable, as their fossil remains are rarely associated with the remains of dead animals.

see also

  • Anoyapitek
  • Griphopithecus
  • Sivapitek
  • Nakalipitek
  • Afropithecus
  • Dryopithecus
  • Morotopithecus
  • Kenyapitek
  • Oreopithecus

Notes

  1. Australopithecus gracile
  2. 1 2 Antonov, Egor. Australopithecus measure age: Littlefoot turned out to be older than Lucy A new "space" technique dates the remains of Littlefoot to about 3.67 million years ago. "Science and Life" (April 13, 2015). Retrieved April 14, 2015.
  3. Beck Roger B. World History: Patterns of Interaction. - Evanston, IL: McDougal Littell. - ISBN 0-395-87274-X.
  4. BBC - Science & Nature - The evolution of man. Mother of man - 3.2 million years ago. Retrieved November 1, 2007. Archived from the original on February 9, 2012.
  5. Thorpe S.K.S.; Holder R.L., and Crompton R.H. PREMOG - Supplementary Info. Origin of Human Bipedalism As an Adaptation for Locomotion on Flexible Branches (inaccessible link - history). Primate Evolution & Morphology Group (PREMOG), the Department of Human Anatomy and Cell Biology, the School of Biomedical Sciences at the University of Liverpool (24 May 2007). Retrieved November 1, 2007. Archived from the original on July 17, 2007.
  6. New human-like species unveiled

Links

  • Australopithecus at the Evolution of Man website
  • Australopithecus on the portal Anthropogenesis.ru
  • The missing link has finally been found in South Africa

australopithecines

Australopithecus Information About

Australopithecus was a genus belonging to the hominin family. They can be described both as bipedal apes and as people with signs of apes. In other words, their structure included features characteristic of the current great apes and humans. These ancient primates lived approximately 6-1 million years ago. The earliest remains found in the Republic of Chad date back to 6 million years old. And the latest, discovered in South Africa, date back to 900 thousand years old. This shows that these ancient hominids lived on Earth for a huge period of time.

The habitat was extremely large. This is practically the whole of Central and Southern Africa, as well as certain areas of North Africa. The bulk of Australopithecus was concentrated in the east and south of the mainland. In the north, the discovered remains are much smaller, but this may only indicate a relatively poor study of this region, and not the actual distribution of these fossil primates. Given the huge time interval, we can talk about cardinal changes natural conditions, which contributed to the emergence of completely new species, unlike the old ones.

Currently, these ancient primates are divided into 3 groups, which successively changed each other. Moreover, each group is divided into several types.

Australopithecus anamanis or early Australopithecus. Lived 6-4 million years ago. Its first remains were found in Kenya in 1965.

Australopithecus afarensis lived 4-2.5 million years ago. In 1974, a French expedition found the skeleton of a female in Ethiopia. She was given the name Lucy. She lived 3.2 million years ago, died at the age of 25 or 30 years.

Australopithecus sediba lived 2.5-1 million years ago. These primates were distinguished by massive forms and well-developed jaws. Initially, 2 skeletons were discovered in Malapa Cave in South Africa. This is a teenager and a female. In total, 130 fragments of these skeletons were found. The word "sediba" from the language of the Basuto people is translated as "well".

Australopithecus lived in tribal groups

Features of the structure of Australopithecus

The hominids under consideration were characterized by a low and wide pelvis, relatively long legs and relatively short arms. The feet did not have grasping functions, only the hands had them. The spine was vertical. That is, we can talk about a similar structure with a person. At the same time, the growth was small and ranged from 120 to 150 cm with a slender build and weight of 30-55 kg.

In females and males, the sizes differed significantly. The strong sex was larger than the weak one by almost 50%. In humans, this difference is no more than 15%. The volume of the brain was 400-550 cubic meters. cm. In humans, the corresponding value is 1200-1500 cubic meters. see As for the structure of the gray matter, it corresponded to the structure of the chimpanzee.

At a later stage of their development, Australopithecus hunted ungulates.

behavioral traits

Australopithecus lived in the savannas and tropical forests near lakes and rivers. At the same time, it cannot be argued that the most ancient primates ignored territories remote from large water bodies. It's just that their remains are best preserved in such places. The diet consisted mainly of plant foods. In later times, hunting for ungulates was practiced.

These ancient ancestors people existed in groups and led a nomadic lifestyle, moving across the hot continent in search of food. It is difficult to say whether they made perfect tools or not. Their hands resembled human ones, but the fingers were narrower and more curved. It is known that in South Africa, 1.5 million years ago, bone fragments were used to catch termites that lived in termite mounds. However, modern apes also use both stones and bones for food.

Australopithecus head in the museum

Were Australopithecus direct ancestors of humans?

When talking about australopithecines, we can assume that they were the direct ancestors of modern humans, based on the fact that a person differs less from a fossil hominid in his characteristics than a gorilla or a chimpanzee. Here you can take as a basis the structure of the jaws, hands, feet, as well as direct walking, which greatly contributed to the development of intelligence.

Here you should know that the first signs of upright walking appeared 6 million years ago in extinct species of monkeys. That is, it was the era when the cardinal formation of the very first ancestors of modern people began. In those days, many open spaces appeared in Africa, which began to be mastered by monkeys. And outside the trees it is much more efficient to move not on 4, but on 2 limbs.

At the same time, it can be assumed that Australopithecus were not at all the direct ancestors of man, but were only a dead end branch evolutionary development. This assumption can neither be confirmed nor refuted, since science has so far collected little data on these and other ancient fossil hominids.

Alexey Starikov