Progressive Australopithecus. Australopithecus. New skills - the basis of survival in the wild

The transition to upright posture had important consequences for the evolution of primates. Bipedal creatures no longer needed thick hair to protect their backs from the relentless sunbeams. Gradually they turned into naked monkeys.;
But most importantly, the transition to upright posture allowed the higher apes to move their own brain to a cooler environment, which made it possible for it to develop into a larger and more active one. In 1924, in a lime quarry near Towns in South Africa, the bones of Australopithecus, extinct higher primates, were found, whose age is 1-5 million years.
Australopithecus, which lived about 3 million years ago, is considered the predecessor of man. These creatures averaged 122-152 cm tall and were upright, as evidenced by the shape of their long leg and arm bones. At the same time, the volume of their skull was no more than that of modern chimpanzees or gorillas.
Scientists attribute the emergence of Australopithecus to the beginning of a cooling period, during which tropical forests began to be gradually replaced by savannahs. The ancestors of Australopithecus are called forms of late driopithecus. The latter were less adapted to the woody environment and therefore switched to living in more open areas. Upright posture significantly complicated the anatomical structure of the brain in Australopithecus, changed the position of the head and eyes. This ensured the expansion of the field of vision - the prerequisites appeared for improving the forms of perception of reality in specific images.
The straightening of the skeleton also contributed to the release of the forelimbs and their transformation into a hand - an organ of labor activity, which was important for further evolution. These features provided Australopithecus with clear advantages in the struggle for existence. Australopithecus lived in the African savannas in close-knit groups of 25-30 individuals, eating not only plant but also animal food. They learned to use various objects such as stones, sticks or bones for hunting and protection from enemies.

Together with the remains of these creatures, primitive bone and stone tools were found, proving that Australopithecus had great intelligence, as opposed to simple animal quick wits. With repeated use, the stones inevitably broke off fragments with a cutting, sharp edge, which were much more effective than ordinary natural stones. The operations of working stones and bones were probably at first isolated cases among Australopithecus, but gradually entrenched by natural selection and turned into the skills of the entire primitive herd.
Around the same time, other creatures lived on the planet - paranthropus (Paranthropus), who ate exclusively plant food and had a more massive physique. But they, unlike Australopithecus, apparently did not make any tools. The extinct bipedal apes, Australopithecus, turned out to be the first reliable representatives of the evolutionary branch that ultimately led to the emergence of Homo sapiens.

Introduction

1. General characteristics of Australopithecus

2. Varieties of Australopithecus

Conclusion

Bibliography


Introduction

The development of the science of the origin of man was constantly stimulated by the search for a "transitional link" between man and ape, more precisely, his ancient ancestor. For a long time, the Pithecanthropes ("monkey-men") of Indonesia, first discovered by the Dutch doctor E. Dubois in Java at the end of the last century, were considered as such a transitional form. With a completely modern locomotor apparatus, Pithecanthropes had a primitive skull and brain mass, approximately 1.5 times less than that of a modern person of the same height. However, this group of hominids turns out to be rather late. Most of the finds in Java have an antiquity of 0.8 to 0.5 million years ago, and the earliest known authentic Pithecanthropus of the Old World is still no older than 1.6-1.5 million years ago.

On the other hand, it follows from the previous review of the finds of Miocene hominids that representatives of the hominid line of evolution have not yet been identified among them paleontologically. It is obvious that the "transitional link" must be sought at the turn of the Tertiary and Quaternary periods, in the Pliocene and Pliocene epochs. This is the time of the existence of the oldest bipedal hominids of Australopithecus.

Hominids are the most highly organized family of great apes. Includes modern man, his predecessors - paleoanthropes and archanthropes, and also, according to most scientists, Australopithecus.

Some scientists limit the family of hominids to only humans themselves, starting with the archanthropes.

Supporters of the extended interpretation of the family include two subfamilies in it: Australopithecus and humans proper (Homininae) with one genus man (Homo) and three species - a skilled man (H. habilis), an upright man (H. erectus) and a reasonable man (H. sapiens ).

Of greatest importance for creating a clear idea of ​​the immediate ancestors of the hominid family are the numerous and well-preserved finds in South Africa (the first was made by Raymond Dart in 1924, their number continues to increase). Now in South and East Africa, several fossil species of anthropomorphic primates have been discovered, which are combined into three genera - Australopithecus, paranthropus and plesianthropes - are distinguished into a subfamily or family of Australopithecus.

Of the three possible centers of origin of the original human ancestor (Africa, Asia, Europe), the most complete connection between the Miocene and later hominids can be traced in Africa. There are fairly late Miocene great apes in Asia and Europe, but no very ancient hominids. Thus, Africa is most likely the ancestral home of the hominids.


1. General characteristics of Australopithecus

The history of the study of Australopithecus dates back to 1924, with the discovery of the skull of a 3-5 year old hominoid cub in the South-Eastern Transvaal (now South Africa) near Taung. The fossil hominoid received the name of the African Australopithecus - Avstralopitecus africanus Dagt, 1925 (from "avstralis" - southern). In subsequent years, other locations of South African Australopithecus were discovered - in Sterkfontein, Makapansgat, Swartkrans, Kromdraai. Their remains were usually found in caves: they lay in travertine deposits of carbon dioxide sources flowing from limestones, or directly in the rocks of the dolomite strata. Initially, new finds received independent generic designations - plesianthropus (Plesianthropus), paranthropus (Paranthropus), but, according to modern ideas, only one genus Avstralopithecus stands out among the South African Australopithecus with two species: the more ancient ("classical") gracile Australopithecus and the later massive, or paranthropus.

In 1959 Australopithecus has also been found in East Africa. The first discovery was made by the spouses M. and L. Leakey in the oldest layer of the Olduvai Gorge on the outskirts of the Serengeti plateau in Tanzania. This hominoid, represented by a rather theromorphic crested skull, was given the name of East African man, since stone artifacts (Zinjanthropus boisei Leakey) were also discovered in the immediate vicinity. Subsequently, the remains of Australopithecus were found in a number of places in East Africa, concentrated mainly in the region of the East African Rift. Usually they are more or less open sites, including areas of grassy forest-steppe.

To date, the remains of at least 500 individuals are known from the territories of South and East Africa. Australopithecus, apparently, could also be found in other regions of the Old World: for example, the so-called Gigantopithecus from Bilaspur in India or the Javanese meganthrope to some extent resemble massive African Australopithecus. However, the position of these forms of hominoids is not entirely clear. Thus, although the diffusion of Australopithecus into the southern regions of Eurasia cannot be ruled out, their bulk is closely related in their distribution to the African continent, where they are found as far south as Hadar in northeast Africa.

The main part of the finds of East African Australopithecus dates back to the period from 4 to 1 million years ago, but the oldest bipeds, apparently, appeared here even earlier, 5.5-4.5 million years ago.

The Australopithecus were a very peculiar group. They appeared about 6-7 million years ago, and the last of them died out only about 900 thousand years ago, during the existence of much more advanced forms. As far as is known, Australopithecus never left Africa, although some finds made on the island of Java are sometimes attributed to this group.

The complexity of the position of Australopithecus among primates lies in the fact that their structure mosaically combines features that are characteristic of both modern great apes and humans. The Australopithecus skull is similar to that of a chimpanzee. Characterized by large jaws, massive bony ridges for the attachment of chewing muscles, a small brain and a large flattened face. Australopithecus teeth were very large, but the fangs were short, and the details of the structure of the teeth were more human than monkey.

The skeletal structure of Australopithecus is characterized by a wide low pelvis, relatively long legs and short arms, a grasping hand and a non-grasping foot, and a vertical spine. Such a structure is already almost human, the differences are only in the details of the structure and in small sizes.

The growth of Australopithecus ranged from a meter to one and a half. It is characteristic that the size of the brain was about 350-550 cm³, that is, like that of modern gorillas and chimpanzees. For comparison, the brain of a modern person has a volume of about 1200-1500 cm³. The brain structure of Australopithecus was also very primitive and differed little from that of a chimp. Already at the stage of Australopithecus, the process of losing the coat probably began. Coming out of the shadow of the forests, our ancestor, in the words of the Soviet anthropologist Ya. Ya. Roginsky, found himself in a “warm coat”, which had to be removed as soon as possible.

The way of life of Australopithecus, apparently, was unlike that known among modern primates. They lived in tropical forests and savannahs, feeding mainly on plants. However, later Australopithecus hunted antelopes or took prey from large predators - lions and hyenas.

Australopithecus lived in groups of several individuals and, apparently, constantly roamed the expanses of Africa in search of food. Australopithecus tools were unlikely to be able to manufacture, although they were used for sure. Their hands were very similar to human ones, but the fingers were more curved and narrower. The oldest tools are known from layers in Ethiopia dated 2.7 million years ago, that is, 4 million years after the appearance of Australopithecus. In South Africa, Australopithecus or their immediate descendants used bone fragments to catch termites from termite mounds about 2-1.5 million years ago.

Australopithecus can be divided into three main groups, in each of which several species are distinguished: early australopithecines - existed from 7 to 4 million years ago, had the most primitive structure. There are several genera and species of early Australopithecus. Gracil Australopithecus - existed from 4 to 2.5 million years ago, had a relatively small size and moderate proportions. Massive Australopithecus - existed from 2.5 to 1 million years ago, were very massively built specialized forms with extremely developed jaws, small front and huge back teeth. Let's consider each of them in more detail.

2. Varieties of Australopithecus

The remains of the oldest primates, which can be attributed to the early Australopithecus, were found in the Republic of Chad in Toros Menalla and named Sahelanthropus tchadensis. The whole skull was given the popular name "Tumai". The dating of the finds is about 6-7 million years ago. More numerous finds in Kenya in Tugen Hills date back to 6 million years ago. They were named Orrorin (Orrorin tugenensis). In Ethiopia, in two locations - Alayla and Aramis - numerous bone remains were found, called Ardipithecus (Ardipithecus ramidus kadabba) (about 5.5 million years ago) and Ardipithecus ramidus ramidus (4.4 million years ago). Finds in two locations in Kenya - Kanapoi and Allia Bay - were named Australopithecus anamensis. They date back to 4 million years ago.

Their growth was not much more than one meter. The brain size was the same as that of a chimpanzee. Early Australopithecus lived in wooded or even swampy places, as well as in forest-steppes.

Obviously, it is these creatures that are most suitable for the role of the notorious "intermediate link" between the monkey and man. We know almost nothing about their way of life, but every year the number of finds is growing, and knowledge about the environment of that distant time is expanding.

Not much is known about early Australopithecus. Judging by the Sahelanthropus skull, Orrorin femurs, skull fragments, limb bones, and Ardipithecus pelvic remains, early Australopithecus were already upright primates.

However, judging by the bones of the hands of Orrorin and Australopithecus of Anamus, they retained the ability to climb trees or even were four-legged creatures that leaned on the phalanges of the fingers, like modern chimpanzees and gorillas. The structure of the teeth of early australopithecines is intermediate between monkeys and humans. It is even possible that Sahelanthropus were relatives of gorillas, Ardipithecus - the immediate ancestors of modern chimpanzees, and Anaman australopithecines died out without leaving descendants. The history of the description of the Ardipithecus skeleton is the clearest example of scientific integrity. After all, between its discovery - in 1994. and description - at the end of 2009, 15 years have passed!

All these long years, an international group of researchers, including the discoverer, Johannes Haile-Selassie, have been working on preserving crumbling bones, reconstructing a skull crushed into a shapeless lump, describing morphological features and searching for a functional interpretation of the smallest details of the structure of bones.

The scientists did not follow the path of presenting another early sensation to the world, but really deeply and carefully studied the most diverse aspects of the find. To do this, scientists had to explore such subtleties of the comparative anatomy of modern great apes and humans, which until now remained unknown. Naturally, data on a variety of fossil primates and australopithecines were also involved in the comparison.

Moreover, the geological conditions of the burial of fossil remains, ancient flora and fauna were considered in the most detailed way, which made it possible to reconstruct the habitat of Ardipithecus more reliably than for many later Australopithecus.

The newly described skeleton of Ardipithecus is a remarkable example of the confirmation of a scientific hypothesis. In his appearance, he perfectly combines the signs of ape and man. In fact, the image that for a century and a half excited the imagination of anthropologists and everyone who cares about our origins has finally become a reality.

Finds in Aramis are numerous - the remains belong to at least 21 individuals, but the most important is the skeleton of an adult female, from which about 45% of the bones remained (more than from the famous "Lucy" - a female Afar australopithecine from Hadar with antiquity 3.2 million years ago ), including almost the entire skull, although in an extremely deformed state. The individual had a height of about 1.2 m. and could weigh up to 50kg. Significantly, the sexual dimorphism of Ardipithecus was much less pronounced than in chimpanzees and even later australopithecines, that is, males were not much larger than females. The brain volume reached 300-350 cm³ - the same as in Sahelanthropus, but less than usual in chimpanzees. The structure of the skull is rather primitive. Remarkably, in Ardipithecus, the face and dentition do not have the specialized features found in Australopithecus and modern apes. Based on this feature, it has even been suggested that Ardipithecus could be the common ancestors of humans and chimpanzees, or even only the ancestors of chimpanzees, but upright ancestors. That is, chimpanzees could have bipedal progenitors. However, a more thorough study showed that this probability is still minimal.

The bipedalism of Ardipithecus is quite obvious, given the structure of its pelvis (combining, however, ape and human morphology) - wide, but also rather high, elongated. However, such signs as the length of the arms reaching the knees, the curved phalanxes of the fingers, the big toe set far aside and retaining the grasping ability, clearly indicate that these creatures could spend a lot of time in the trees. The authors of the original description emphasize the fact that Ardipithecus lived in fairly closed habitats, with a large number of trees and thickets. In their opinion, such biotopes exclude the classical theory of the formation of bipedal locomotion under conditions of climate cooling and the reduction of tropical forests. O. Lovejoy, based on the weak sexual dimorphism of Ardipithecus, develops his old hypothesis about the development of bipedality on the basis of social and sexual relationships, without direct connection with climatic and geographic conditions. However, the situation can be viewed differently, because approximately the same conditions that were reconstructed for Aramis were assumed by supporters of the hypothesis of the origin of bipedia in the conditions of displacement of forests by savannahs. It is clear that the tropical forests could not disappear instantly, and the monkeys could not master the savanna within one or two generations. It is remarkable that this stage has now been studied in such detail using the example of the Ardipithecus of Aramis.

These creatures could live both in trees and on the ground, climbing branches and walking on two legs, and sometimes, perhaps, even getting down on all fours. They apparently fed on a wide range of plants, both shoots with leaves and fruits, avoiding any specialization, which became the key to future human omnivorousness. It is clear that the social structure is unknown to us, but the small size of the fangs and weak sexual dimorphism indicate a low level of aggression and weak inter-male competition, apparently less excitability, which resulted after millions of years in the ability of a modern person to concentrate, learn, carefully, accurately and smoothly perform work activities, cooperate, coordinate and coordinate their actions with other members of the group. It is these parameters that distinguish a person from a monkey. It is curious that many morphological features of modern apes and humans are apparently based on behavioral features. This applies, for example, to the large size of the jaws of chimpanzees, which are caused not by some specific need for nutrition, but by increased inter-male and intra-group aggressiveness and excitability. It is noteworthy that bonobo pygmy chimpanzees, much friendlier than their common counterparts, have shortened jaws, relatively small fangs, and less pronounced sexual dimorphism.

Based on a comparative study of Ardipithecus, chimpanzees, gorillas and modern humans, it was concluded that many features of great apes arose independently.

This applies, for example, to such a specialized feature as moving on bent phalanges of fingers in chimpanzees and gorillas.

Until now, it was believed that a single line of great apes first separated from the line of hominids, which then split into gorillas and chimpanzees.

However, chimpanzees are more similar to Ardipithecus than to gorillas in a number of ways, so the separation of the gorilla lineage must have occurred before the specialization for walking on the phalanges appeared, which Ardipithecus does not have. However, this hypothesis has its weaknesses; if desired, the matter can be presented in another way.

Comparison of Ardipithecus with Sahelanthropus and later Australopithecus once again showed that the evolution of human ancestors was in some jerks.

The general level of development in Sahelanthropus 6-7 million years ago and Ardipithecus 4.4 million years ago is almost the same, while after only 200 thousand years (4.2 million years ago), the Anaman australopithecines developed many new features, which, in turn, , changed little until the time of the appearance of "early Homo" 2.3-2.6 million years ago. Such jumps or turns of evolution were known before, but now we have the opportunity to determine the exact time of one more of them; one can try to explain them by linking them, for example, with climate change.

One of the most surprising conclusions that can be drawn from the study of Ardipithecus is that man, in many ways, differs from the common ancestor with chimpanzees less than a chimpanzee or a gorilla. And this applies, first of all, to the size of the jaws and the structure of the hand and foot - parts of the body, the structural features of which in humans are most often paid attention to.

In Kenya, Tanzania and Ethiopia, fossils of gracile australopithecines called Australopithecus afarensis have been discovered in many locations. This species existed approximately 4 to 2.5 million years ago. The best-known finds are from the Hadar area in the Afar Desert, including a skeleton nicknamed Lucy. Also, in Tanzania, fossilized footprints of erect walking creatures were found in the same layers in which the remains of the Afar australopithecines were found.

In addition to the Afar australopithecines, other species probably lived in East and North Africa in the time interval of 3-3.5 million years ago. In Kenya, a skull and other fossils have been found at Lomekwi, described as Kenyanthropus platyops. In the Republic of Chad, in Koro Toro (East Africa), a single fragment of the jaw, described as Australopithecus bahrelghazali, was found. In South Africa, in a number of localities - Taung, Sterkfontein and Makapansgat - numerous fossils known as African Australopithecus (Australopithecus africanus) have been discovered. The first find of Australopithecus belonged to this species - the skull of a cub known as Baby from Taung (R. Dart, 1924). African Australopithecus lived from 3.5 to 2.4 million years ago. The latest gracile Australopithecus - dated to about 2.5 million years ago - was discovered in Ethiopia in Bowri and named Australopithecus gari (Australopithecus garhi).

From gracile australopithecines, all parts of the skeleton from many individuals are known, therefore, reconstructions of their appearance and lifestyle are very reliable. Gracil Australopithecus were upright creatures about 1-1.5 meters tall. Their gait was somewhat different from that of a human. Apparently, Australopithecus walked with shorter steps, and the hip joint did not fully extend when walking. Together with a fairly modern structure of the legs and pelvis, the arms of Australopithecus were somewhat elongated, and the fingers were adapted for climbing trees, but these signs can only be a legacy from ancient ancestors.

During the day, Australopithecus roamed the savannah or forests, along the banks of rivers and lakes, and in the evening they climbed trees, as modern chimpanzees do. Australopithecus lived in small herds or families and were able to travel quite long distances. They ate mainly plant food, and they usually did not make tools, although not far from the bones of Australopithecus gari, scientists found stone tools and antelope bones crushed by them. Also, for the South African australopithecines (Makapansgat cave), R. Dart put forward a hypothesis of osteodontokeratic (literally - “bone-dental-horn”) culture. It was assumed that Australopithecus used the bones, horns and teeth of animals as tools. Later studies have shown that most of the wear marks on these bones are the result of gnawing from hyenas and other predators.

Like the early members of the genus, the gracile australopithecines had an ape-like skull that matched the almost modern rest of the skeleton. The Australopithecus brain was similar to that of a monkey in both size and shape. However, the ratio of brain mass to body mass in these primates was intermediate between a small simian and a very large human.

Approximately 2.5-2.7 million years ago, new species of hominids arose, which had a large brain and were already attributed to the genus Homo. However, there was another group of late Australopithecus that deviated from the line leading to man - the massive Australopithecus.

The oldest massive australopithecines are known from Kenya and Ethiopia - Lokalei and Omo. They have dates about 2.5 million years ago and are called Ethiopian Paranthropus (Paranthropus aethiopicus). Later massive australopithecines from East Africa - Olduvai, Koobi-Fora - dating from 2.5 to 1 million years ago are described as Paranthropus Boys (Paranthropus boisei). In South Africa - Swartkrans, Kromdraai, Dreamolen Cave - massive Paranthropus (Paranthropus robustus) are known. The massive Paranthropus was the second species of Australopithecus to be discovered.

When examining the skull of Paranthropus, huge jaws and large bone ridges are striking, which served to attach the chewing muscles. The jaw apparatus reached its maximum development in East African Paranthropus. The first open skull of this species, due to the size of the teeth, even received the nickname "The Nutcracker".

Paranthropes were large - up to 70 kg in weight - specialized herbivorous creatures that lived along the banks of rivers and lakes in dense thickets. Their way of life was somewhat reminiscent of the way of life of modern gorillas. However, they retained their bipedal gait and may even have been able to make tools. In layers with paranthropes, stone tools and bone fragments were found, with which hominids tore up termite mounds. Also, the hand of these primates was adapted for the manufacture and use of tools.

The paranthropes "made a bet" on size and herbivory. This led them to ecological specialization and extinction. However, in the same layers with paranthropes, the remains of the first representatives of hominins - the so-called "early Homo" - more progressive hominids with a large brain, were found.


Conclusion

As studies of recent decades have shown, Australopithecus were the immediate evolutionary predecessors of man. It was from among the progressive representatives of these two-legged fossil primates that about three million years ago, creatures emerged in East Africa who made the first artificial tools, created the oldest Paleolithic culture - the Olduvai, and thereby laid the foundation for the human race.


Bibliography

1. Alekseev V.P. Man: evolution and taxonomy (some theoretical issues). Moscow: Nauka, 1985.

2. Human biology / ed. J.Harrison, J.Wiker, J.Tenner et al. M.: Mir, 1979.

3. Bogatenkov D.V., Drobyshevsky S.V. Anthropology / Ed. T.I. Alekseeva. - M., 2005.

4. Large illustrated atlas of primitive man. Prague: Artia, 1982.

5. Boriskovsky P.I. The emergence of human society / The emergence of human society. Paleolithic of Africa. - L .: Nauka, 1977.

6. Bunak V.V. Genus Homo, its origin and subsequent evolution. - M., 1980.

7. Gromova V.I. Hipparions. Proceedings of the Paleontological Institute of the Academy of Sciences of the USSR, 1952. V.36.

8. Johanson D. Go M. Lucy: the origins of the human race. M.: Mir, 1984.

9. Zhedenov V.N. Comparative anatomy of primates (including humans) / Ed. M.F. Nesturkha, M.: Higher school, 1969.

10. Zubov A.A. Dental system / Fossil hominids and the origin of man. Edited by V.V. Bunak. Proceedings of the Institute of Ethnography. N.S. 1966, Vol.92.

11. Zubov A.A. Odontology. Methods of anthropological research. M: Nauka, 1968.

12. Zubov A.A. On the systematics of Australopithecus. Questions of Anthropology, 1964.

14. Reshetov V.Yu. Tertiary history of higher primates//Itogi nauki i tekhniki. Series Stratigraphy. Paleontology M., VINITI, 1986, V.13.

15. Roginsky Ya.Ya., Levin M.G. Anthropology. Moscow: Higher school, 1978.

16. Roginsky Ya.Ya. Problems of anthropogenesis. Moscow: Higher school, 1977.

17. Sinitsyn V.M. Ancient climates of Eurasia. L .: Publishing house of Leningrad State University, 1965 Part 1.

18. Khomutov A.E. Anthropology. - Rostov n / D .: Phoenix, 2002.

19. Khrisanfova E.N. The oldest stages of hominization//Itogi nauki i tekhniki. Series Anthropology. M.: VINITI, 1987, V.2.

20. Yakimov V.P. Australopithecus. / Fossil hominids and the origin of man / Under the editorship of V.V. Bunak / / Proceedings of the Institute of Ethnography, 1966. V.92.


Bogatenkov D.V., Drobyshevsky S.V. Anthropology / Ed. T.I. Alekseeva. - M., 2005.

Khomutov A.E. Anthropology. - Rostov n / a.: Phoenix, 2002

Bunak V.V. Genus Homo, its origin and subsequent evolution. - M., 1980.

Zubov A.A. On the systematics of Australopithecus. Questions of Anthropology, 1964.

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. Taking into account the huge time interval, we can talk about cardinal changes in 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 savannahs 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 human ancestors lived 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 straight 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 represented only a dead end branch of 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

2. Varieties of Australopithecus

The remains of the oldest primates, which can be attributed to the early Australopithecus, were found in the Republic of Chad in Toros Menalla and named Sahelanthropus tchadensis. The whole skull was given the popular name "Tumai". The dating of the finds is about 6-7 million years ago. More numerous finds in Kenya in Tugen Hills date back to 6 million years ago. They were named Orrorin (Orrorin tugenensis). In Ethiopia, in two locations - Alayla and Aramis - numerous bone remains were found, called Ardipithecus (Ardipithecus ramidus kadabba) (about 5.5 million years ago) and Ardipithecus ramidus ramidus (4.4 million years ago). Finds in two locations in Kenya - Kanapoi and Allia Bay - were named Australopithecus anamensis. They date back to 4 million years ago.

Their growth was not much more than one meter. The brain size was the same as that of a chimpanzee. Early Australopithecus lived in wooded or even swampy places, as well as in forest-steppes.

Obviously, it is these creatures that are most suitable for the role of the notorious "intermediate link" between the monkey and man. We know almost nothing about their way of life, but every year the number of finds is growing, and knowledge about the environment of that distant time is expanding.

Not much is known about early Australopithecus. Judging by the Sahelanthropus skull, Orrorin femurs, skull fragments, limb bones, and Ardipithecus pelvic remains, early Australopithecus were already upright primates.

However, judging by the bones of the hands of Orrorin and Australopithecus of Anamus, they retained the ability to climb trees or even were four-legged creatures that leaned on the phalanges of the fingers, like modern chimpanzees and gorillas. The structure of the teeth of early australopithecines is intermediate between monkeys and humans. It is even possible that Sahelanthropus were relatives of gorillas, Ardipithecus - the immediate ancestors of modern chimpanzees, and Anaman australopithecines died out without leaving descendants. The history of the description of the Ardipithecus skeleton is the clearest example of scientific integrity. After all, between its discovery - in 1994. and description - at the end of 2009, 15 years have passed!

All these long years, an international group of researchers, including the discoverer, Johannes Haile-Selassie, have been working on preserving crumbling bones, reconstructing a skull crushed into a shapeless lump, describing morphological features and searching for a functional interpretation of the smallest details of the structure of bones.

The scientists did not follow the path of presenting another early sensation to the world, but really deeply and carefully studied the most diverse aspects of the find. To do this, scientists had to explore such subtleties of the comparative anatomy of modern great apes and humans, which until now remained unknown. Naturally, data on a variety of fossil primates and australopithecines were also involved in the comparison.

Moreover, the geological conditions of the burial of fossil remains, ancient flora and fauna were considered in the most detailed way, which made it possible to reconstruct the habitat of Ardipithecus more reliably than for many later Australopithecus.

The newly described skeleton of Ardipithecus is a remarkable example of the confirmation of a scientific hypothesis. In his appearance, he perfectly combines the signs of ape and man. In fact, the image that for a century and a half excited the imagination of anthropologists and everyone who cares about our origins has finally become a reality.

Finds in Aramis are numerous - the remains belong to at least 21 individuals, but the most important is the skeleton of an adult female, from which about 45% of the bones remained (more than from the famous "Lucy" - a female Afar australopithecine from Hadar with antiquity 3.2 million years ago ), including almost the entire skull, although in an extremely deformed state. The individual had a height of about 1.2 m. and could weigh up to 50kg. Significantly, the sexual dimorphism of Ardipithecus was much less pronounced than in chimpanzees and even later australopithecines, that is, males were not much larger than females. The brain volume reached 300-350 cm³ - the same as in Sahelanthropus, but less than usual in chimpanzees. The structure of the skull is rather primitive. Remarkably, in Ardipithecus, the face and dentition do not have the specialized features found in Australopithecus and modern apes. Based on this feature, it has even been suggested that Ardipithecus could be the common ancestors of humans and chimpanzees, or even only the ancestors of chimpanzees, but upright ancestors. That is, chimpanzees could have bipedal progenitors. However, a more thorough study showed that this probability is still minimal.

The bipedalism of Ardipithecus is quite obvious, given the structure of its pelvis (combining, however, ape and human morphology) - wide, but also rather high, elongated. However, such signs as the length of the arms reaching the knees, the curved phalanxes of the fingers, the big toe set far aside and retaining the grasping ability, clearly indicate that these creatures could spend a lot of time in the trees. The authors of the original description emphasize the fact that Ardipithecus lived in fairly closed habitats, with a large number of trees and thickets. In their opinion, such biotopes exclude the classical theory of the formation of bipedal locomotion under conditions of climate cooling and the reduction of tropical forests. O. Lovejoy, based on the weak sexual dimorphism of Ardipithecus, develops his old hypothesis about the development of bipedality on the basis of social and sexual relationships, without direct connection with climatic and geographic conditions. However, the situation can be viewed differently, because approximately the same conditions that were reconstructed for Aramis were assumed by supporters of the hypothesis of the origin of bipedia in the conditions of displacement of forests by savannahs. It is clear that the tropical forests could not disappear instantly, and the monkeys could not master the savanna within one or two generations. It is remarkable that this stage has now been studied in such detail using the example of the Ardipithecus of Aramis.

These creatures could live both in trees and on the ground, climbing branches and walking on two legs, and sometimes, perhaps, even getting down on all fours. They apparently fed on a wide range of plants, both shoots with leaves and fruits, avoiding any specialization, which became the key to future human omnivorousness. It is clear that the social structure is unknown to us, but the small size of the fangs and weak sexual dimorphism indicate a low level of aggression and weak inter-male competition, apparently less excitability, which resulted after millions of years in the ability of a modern person to concentrate, learn, carefully, accurately and smoothly perform work activities, cooperate, coordinate and coordinate their actions with other members of the group. It is these parameters that distinguish a person from a monkey. It is curious that many morphological features of modern apes and humans are apparently based on behavioral features. This applies, for example, to the large size of the jaws of chimpanzees, which are caused not by some specific need for nutrition, but by increased inter-male and intra-group aggressiveness and excitability. It is noteworthy that bonobo pygmy chimpanzees, much friendlier than their common counterparts, have shortened jaws, relatively small fangs, and less pronounced sexual dimorphism.

Based on a comparative study of Ardipithecus, chimpanzees, gorillas and modern humans, it was concluded that many features of great apes arose independently.

This applies, for example, to such a specialized feature as moving on bent phalanges of fingers in chimpanzees and gorillas.

Until now, it was believed that a single line of great apes first separated from the line of hominids, which then split into gorillas and chimpanzees.

However, chimpanzees are more similar to Ardipithecus than to gorillas in a number of ways, so the separation of the gorilla lineage must have occurred before the specialization for walking on the phalanges appeared, which Ardipithecus does not have. However, this hypothesis has its weaknesses; if desired, the matter can be presented in another way.

Comparison of Ardipithecus with Sahelanthropus and later Australopithecus once again showed that the evolution of human ancestors was in some jerks.

The general level of development in Sahelanthropus 6-7 million years ago and Ardipithecus 4.4 million years ago is almost the same, while after only 200 thousand years (4.2 million years ago), the Anaman australopithecines developed many new features, which, in turn, , changed little until the time of the appearance of "early Homo" 2.3-2.6 million years ago. Such jumps or turns of evolution were known before, but now we have the opportunity to determine the exact time of one more of them; one can try to explain them by linking them, for example, with climate change.

One of the most surprising conclusions that can be drawn from the study of Ardipithecus is that man, in many ways, differs from the common ancestor with chimpanzees less than a chimpanzee or a gorilla. And this applies, first of all, to the size of the jaws and the structure of the hand and foot - parts of the body, the structural features of which in humans are most often paid attention to.

In Kenya, Tanzania and Ethiopia, fossils of gracile australopithecines called Australopithecus afarensis have been discovered in many locations. This species existed approximately 4 to 2.5 million years ago. The best-known finds are from the Hadar area in the Afar Desert, including a skeleton nicknamed Lucy. Also, in Tanzania, fossilized footprints of erect walking creatures were found in the same layers in which the remains of the Afar australopithecines were found.

In addition to the Afar australopithecines, other species probably lived in East and North Africa in the time interval of 3-3.5 million years ago. In Kenya, a skull and other fossils have been found at Lomekwi, described as Kenyanthropus platyops. In the Republic of Chad, in Koro Toro (East Africa), a single fragment of the jaw, described as Australopithecus bahrelghazali, was found. In South Africa, in a number of localities - Taung, Sterkfontein and Makapansgat - numerous fossils known as African Australopithecus (Australopithecus africanus) have been discovered. The first find of Australopithecus belonged to this species - the skull of a cub known as Baby from Taung (R. Dart, 1924). African Australopithecus lived from 3.5 to 2.4 million years ago. The latest gracile Australopithecus - dated to about 2.5 million years ago - was discovered in Ethiopia in Bowri and named Australopithecus gari (Australopithecus garhi).

From gracile australopithecines, all parts of the skeleton from many individuals are known, therefore, reconstructions of their appearance and lifestyle are very reliable. Gracil Australopithecus were upright creatures about 1-1.5 meters tall. Their gait was somewhat different from that of a human. Apparently, Australopithecus walked with shorter steps, and the hip joint did not fully extend when walking. Together with a fairly modern structure of the legs and pelvis, the arms of Australopithecus were somewhat elongated, and the fingers were adapted for climbing trees, but these signs can only be a legacy from ancient ancestors.

During the day, Australopithecus roamed the savannah or forests, along the banks of rivers and lakes, and in the evening they climbed trees, as modern chimpanzees do. Australopithecus lived in small herds or families and were able to travel quite long distances. They ate mainly plant food, and they usually did not make tools, although not far from the bones of Australopithecus gari, scientists found stone tools and antelope bones crushed by them. Also, for the South African australopithecines (Makapansgat cave), R. Dart put forward a hypothesis of osteodontokeratic (literally - “bone-dental-horn”) culture. It was assumed that Australopithecus used the bones, horns and teeth of animals as tools. Later studies have shown that most of the wear marks on these bones are the result of gnawing from hyenas and other predators.

Like the early members of the genus, the gracile australopithecines had an ape-like skull that matched the almost modern rest of the skeleton. The Australopithecus brain was similar to that of a monkey in both size and shape. However, the ratio of brain mass to body mass in these primates was intermediate between a small simian and a very large human.

Approximately 2.5-2.7 million years ago, new species of hominids arose, which had a large brain and were already attributed to the genus Homo. However, there was another group of late Australopithecus that deviated from the line leading to man - the massive Australopithecus.

The oldest massive australopithecines are known from Kenya and Ethiopia - Lokalei and Omo. They have dates about 2.5 million years ago and are called Ethiopian Paranthropus (Paranthropus aethiopicus). Later massive australopithecines from East Africa - Olduvai, Koobi-Fora - dating from 2.5 to 1 million years ago are described as Paranthropus Boys (Paranthropus boisei). In South Africa - Swartkrans, Kromdraai, Dreamolen Cave - massive Paranthropus (Paranthropus robustus) are known. The massive Paranthropus was the second species of Australopithecus to be discovered.

When examining the skull of Paranthropus, huge jaws and large bone ridges are striking, which served to attach the chewing muscles. The jaw apparatus reached its maximum development in East African Paranthropus. The first open skull of this species, due to the size of the teeth, even received the nickname "The Nutcracker".

Paranthropes were large - up to 70 kg in weight - specialized herbivorous creatures that lived along the banks of rivers and lakes in dense thickets. Their way of life was somewhat reminiscent of the way of life of modern gorillas. However, they retained their bipedal gait and may even have been able to make tools. In layers with paranthropes, stone tools and bone fragments were found, with which hominids tore up termite mounds. Also, the hand of these primates was adapted for the manufacture and use of tools.

The paranthropes "made a bet" on size and herbivory. This led them to ecological specialization and extinction. However, in the same layers with paranthropes, the remains of the first representatives of hominins - the so-called "early Homo" - more progressive hominids with a large brain, were found.


Conclusion

As studies of recent decades have shown, Australopithecus were the immediate evolutionary predecessors of man. It was from among the progressive representatives of these two-legged fossil primates that about three million years ago, creatures emerged in East Africa who made the first artificial tools, created the oldest Paleolithic culture - the Olduvai, and thereby laid the foundation for the human race.


Bibliography

1. Alekseev V.P. Man: evolution and taxonomy (some theoretical issues). Moscow: Nauka, 1985.

2. Human biology / ed. J.Harrison, J.Wiker, J.Tenner et al. M.: Mir, 1979.

3. Bogatenkov D.V., Drobyshevsky S.V. Anthropology / Ed. T.I. Alekseeva. - M., 2005.

4. Large illustrated atlas of primitive man. Prague: Artia, 1982.

5. Boriskovsky P.I. The emergence of human society / The emergence of human society. Paleolithic of Africa. - L .: Nauka, 1977.

6. Bunak V.V. Genus Homo, its origin and subsequent evolution. - M., 1980.

7. Gromova V.I. Hipparions. Proceedings of the Paleontological Institute of the Academy of Sciences of the USSR, 1952. V.36.

8. Johanson D. Go M. Lucy: the origins of the human race. M.: Mir, 1984.

9. Zhedenov V.N. Comparative anatomy of primates (including humans) / Ed. M.F. Nesturkha, M.: Higher school, 1969.

10. Zubov A.A. Dental system / Fossil hominids and the origin of man. Edited by V.V. Bunak. Proceedings of the Institute of Ethnography. N.S. 1966, Vol.92.

11. Zubov A.A. Odontology. Methods of anthropological research. M: Nauka, 1968.

12. Zubov A.A. On the systematics of Australopithecus. Questions of Anthropology, 1964.

14. Reshetov V.Yu. Tertiary history of higher primates//Itogi nauki i tekhniki. Series Stratigraphy. Paleontology M., VINITI, 1986, V.13.

15. Roginsky Ya.Ya., Levin M.G. Anthropology. M.: Higher school, 1978.

16. Roginsky Ya.Ya. Problems of anthropogenesis. M.: Higher school, 1977.

17. Sinitsyn V.M. Ancient climates of Eurasia. L .: Publishing house of Leningrad State University, 1965 Part 1.

18. Khomutov A.E. Anthropology. - Rostov n / D .: Phoenix, 2002.

19. Khrisanfova E.N. The oldest stages of hominization//Itogi nauki i tekhniki. Series Anthropology. M.: VINITI, 1987, V.2.

20. Yakimov V.P. Australopithecus. / Fossil hominids and the origin of man / Under the editorship of V.V. Bunak / / Proceedings of the Institute of Ethnography, 1966. V.92.


Bogatenkov D.V., Drobyshevsky S.V. Anthropology / Ed. T.I. Alekseeva. - M., 2005.

Khomutov A.E. Anthropology. - Rostov n / a.: Phoenix, 2002

Bunak V.V. Genus Homo, its origin and subsequent evolution. - M., 1980.


Australopithecus - bipedal apes.

First finds. For the first time, the name Australopithecus appeared in the scientific literature in connection with the fossil finds of Raymond Dart, in 1924 he discovered in the dolomite deposits of the South-Eastern Transvaal, near the town of Taung, the skull of a 3-5-year-old hominoid cub (“Taung baby”). The bones of the skull had a greater degree of "monkey" features with very slight manifestations of "human" features in the structure of the jaws. The internal capacity of the skull was also more in line with the average for most fossil and modern great apes - 380-450 cm 3 .

African Australopithecus (Australopithecus afarensis) - this is how R. Dart called his find, determining the age of Australopithecus at 1.7-2.0 million years. Later, in a number of places in South Africa, in addition to the bones of the skull, the remains of the postcranial skeleton of Australopithecus were found, according to which it was possible to establish the ability for bipedal locomotion. Systematics of Australopithecus. Sometimes australopithecines are isolated in a separate family or referred to as pongids. In this case, they will be considered as real hominids. Among anthropologists, there are different ideas about the number of species within the genus Homo. The position of Australopithecus in the family of hominids can be considered quite reasonable: firstly, some species of Australopithecus probably participated in the origin of later human ancestors; secondly, it is rather difficult to draw a line separating Australopithecus from the first "true" Homo.

Variety of Australopithecus. To determine the physical type of Australopithecus, the main features can be distinguished: bipedalism, small brain, large teeth with thick enamel (megadontia), small fangs, the absence of a pronounced set of features in the structure of the upper limbs associated with the production of artificial stone tools. At the same time, depending on antiquity and biological specialization, morphological characteristics can vary quite significantly. The most recent finds have determined the chronological framework for the existence of all known types of Australopithecus from 1 to 7 million years.
In general, Australopithecus can be conditionally divided into three main groups, different in morphology and comparatively successive in time:

a) early australopithecines;

b) gracile australopithecines;

c) massive australopithecines.

Morphology of Australopithecus

A detailed study of the morphology of all currently known species of australopithecines makes it possible to understand the most complex problems of the formation of bipedal locomotion, the enhanced development of the brain, and the appearance of culture in subsequent hominids. Bipedal locomotion, as the most ancient system of hominization, began to form, apparently, already in pre-Australopithecines and is quite well traced in the earliest Australopithecus about 7 million years ago. To the greatest extent, bipedal locomotion affects the structure of the pelvic girdle:

There is an expansion of the ilium anteriorly, its middle part is strengthened;
The sacroiliac and hip joints are strengthened and their convergence occurs;
Elements of the muscular-ligamentous apparatus develop, fixing the extension of the leg in the hip and knee joints;
In Australopithecus, the shape of the pelvis and the hip joint as a whole were similar to those of a human, they possessed a constant bipedal gait, which fundamentally distinguished them from all known fossils and modern apes.

The brain of Australopithecus corresponded in absolute size to variations in its mass in modern great apes. Individual values ​​of brain volume ranged from 300 to 570 cm 3 . There is no clear idea about changes in the structure of the brain (for this, endocranes are used - internal casts of the brain). There is an opinion about the pongid type of brain structure of Australopithecus.

At the same time, progressive reorganizations are noted while maintaining a small volume of the brain itself: an increase in the parietal and temporal associative zones. The structure of the skull and dental system of Australopithecus also has many simian features. The face was large, pronounced prognathism, the chin was absent, the nose was flat and wide, the base of the skull was slightly curved, which testified to the primitiveness of the vocal apparatus. The stages of development of permanent teeth in Australopithecus were more similar to those in modern apes than in humans.

1. Gorilla; 2. Australopithecus; 3. Pithecanthropus; 4. Neanderthal; 5. Modern man.

Habitat of australopithecines. The ecological conditions against which the evolution of Australopithecus proceeded for more than 6 million years changed quite significantly. In Africa, the general cooling of that time affected the gradual decrease in humidity and changes in the landscape to more open and dry ones. The driest conditions of all known in Africa characterize the location of the massive Australopithecus in Peninga (Tanzania), where the landscape was an open grassy savannah.


Have questions?

Report a typo

Text to be sent to our editors: