New data has made it possible to clarify the pedigree of the animal kingdom. New data has made it possible to clarify the pedigree of the animal kingdom Genetic closeness of people
The diagram is compiled according to the latest scientific data from the Anthropogenesis.ru portal (Compiled by Georgy Popov, k-ya.rf)
“Our ancestors went through a long and amazing path of development. They changed themselves and changed the world around them. Some groups fell into evolutionary dead ends and died out, but the remaining groups repopulated the planet. They invented tools, tamed fire, discovered continents and created the first art. Anthropogenesis is the study of all this - an interesting and rapidly developing scientific discipline” - Scientific editor of the portal Anthropogenesis.ru - Candidate of Biological Sciences, Associate Professor of the Department of Anthropology, Faculty of Biology, Moscow State University. Lomonosov Stanislav Drobyshevsky.
Purgatorius.
These possible ancestors of all primates appeared about 65 million years ago. They were in many ways similar to rodents: the size of a mouse or rat, an elongated muzzle, a small, simply structured brain, eyes located on the sides of the head, short massive paws, a long tail. They lived in trees, caught insects and ate plants. Even in the early stages of evolution, primates were extremely diverse.
1) Humanoids.
Proconsul.
In the structure of representatives of this family there are still numerous features characteristic of lower apes. Some species may have had a tail. Arms and legs are approximately the same length. However, the structural features of the skull (a flatter face, smaller fangs, a brain enlarged to 300 g) indicate that these creatures belong to apes. Their food was soft fruits and fruits.
Nakalipithecus.
Nakalipithecus, who lived about 10 million years ago, is the most likely last common ancestor of gorillas, chimpanzees and humans. This is one of the “missing links” facing early australopithecus, so the discovery of Nakalipithecus is one of the most important in paleoanthropology. Most likely, he was still four-legged. The fossil's teeth are covered with a thick layer of enamel, indicating a diet of solid food, probably seeds and nuts.
Horatpithecus.
Horatpithecus - the most likely ancestor of orangutans - lived from 14 to 7 million years ago in tropical forests. Two fossil species have been discovered in Southeast Asia (Thailand). Analysis of the structure of their teeth showed that these apes preferred soft fruits and seeds. Apparently, they were not adapted to life in trees and moved on the ground.
Gigantopithecus.
Gigantopithecus is the largest primate in history. They separated from the “human” branch about nine million years ago, and became extinct only about 100 thousand years ago, having existed side by side with our ancestors for almost a million years. The jaws and teeth of Gigantopithecus were sometimes twice as large as those of modern gorillas, so the size of the skull and body must have been simply enormous. A height of three or even four meters is quite a reliable value for them.
Orangutan.
Orangutans live in the forests of Southeast Asia: on the islands of Kalimantan and Sumatra. These are large monkeys, reaching a height of up to 160 cm. The physique is clumsy: long arms - their span reaches three meters - powerful, thick, with a short first finger, large belly. The hair is sparse but long. The coat color is reddish-red. The hands and feet of orangutans are adapted exclusively to an arboreal lifestyle. These monkeys do not “fly” like gibbons, but climb and walk along branches, and do this slowly and carefully. They live in tall trees, where they place their nest-beds at night. They rarely descend to the ground; they walk on all fours, supporting themselves on the phalanges of their fingers. The word "orangutan" is of Malay origin, made up of two words meaning "man of the forest". Adding the letter “g” at the end sharply distorts the meaning, meaning “a person is in debt.” This wonderful anthropoid owes nothing to anyone.
Gorilla.
The gorilla lives exclusively in Equatorial Africa. There is evidence that the growth of gorillas exceeded two meters. The body is heavy, barrel-shaped, with a wide chest (up to 175 cm in girth), a thick belly, a short neck, broad shoulders, and a large head. The forelimbs are longer than the hind limbs. The brain is large, up to 600 cm3. Over the years, incredible accounts of the extraordinary ferocity of gorillas have been reported. However, the “bloodthirsty giant” is a rather good-natured vegetarian, leading a leisurely, quiet life in groups where relations are very peaceful. Gorillas are characterized by a terrestrial lifestyle, although their limbs are also adapted for climbing trees. The gorilla can freely stand on its feet, freeing its hands not only for thunderclaps on its own chest, but also for very subtle food manipulation. Natural gorilla populations are in dangerous decline.
Chimpanzee.
The common chimpanzee lives in Equatorial Africa and surrounding areas. The pygmy chimpanzee, or bonobo, is found in the tropical forests of Central Africa between the Congo and Lualaba rivers. Chimpanzees are smaller than orangutans and gorilla. The fingers are long, with nails. The arms are much longer than the legs. Chimpanzees' limbs are adapted for walking on the ground, as well as for climbing trees, where the monkeys build nests at night. Chimpanzees can make enormous journeys, sometimes walking more than 50 km a day. Mainly herbivores. Bonobos also eat insects, honey, many cultivated plants, and even fish. Common chimpanzees eat fruits, leaves, stem cores, buds and buds of plants, and often hunt mammals. Chimpanzees have the richest means of communication. They are in danger of extinction.
The description of modern monkeys is based on material from the book: Friedman E.P. Primates. – M.: Nauka, 1979. – 208 p.
2. Australopithecus early.
Sahelanthropus.
Sahelanthropus, who lived 7.2–6.8 million years ago, is the oldest known human ancestor that was no longer also the ancestor of chimpanzees. He was also the oldest upright walking primate. Its upright posture is evidenced by the structure of the skull: the spine was attached to the skull not from the back, like in quadrupeds, but from below. The “monkey” features are: lack of a forehead, a powerful eyebrow, impressive jaws and a small brain (about 350 g, like that of modern chimpanzees). The habitat of Sahelanthropus could be the shores of lakes covered with sparse forests.
Ororin.
Orrorin's femurs have many features that distinguish him from apes, and clearly indicate a bipedal mode of locomotion. At the same time, the structure of the upper limbs indicates that their owner sometimes moved through trees (as did later australopithecines). Orrorin was approximately 1.1–1.2 meters tall or slightly taller. In popular literature, this Australopithecus is known as the "Millennium Man".
Ardipithecus.
Ardipithecus, although they lived two million years later than Sahelanthropus, was not so close to Homo sapiens. For example, the foot, despite being adapted to walking upright, was more like a palm with a fully abductible, grasping thumb. In its appearance, Ardipithecus ideally combined the characteristics of a monkey and a human. These creatures, just over a meter tall, could live in trees and on the ground, climb branches and walk on two legs, and sometimes go down on all fours. They apparently ate a very varied diet, which became the key to future human omnivory. A number of signs (for example, a slight difference between females and males and very small fangs) indicate that in the Ardipithecus “society” it was customary to “negotiate” with each other rather than sort things out with brute force. This quality gradually led our ancestors to the ability to unite into groups, carry out work activities harmoniously, and coordinate their actions with other members of the group. It is these inclinations that distinguish man from ape.
Australopithecus anamensis.
This Australopithecus is a descendant of Ardipithecus and the ancestor of later Australopithecus. The structure of its skeleton combines the characteristics of humans and monkeys in approximately equal proportions. With developed upright walking, Australopithecus anamensis sometimes probably walked on all fours, supported by bent fingers (as evidenced by the structure of the radius). Like its ancestors and unlike its descendants, Australopithecus anamensis fed mainly on forest vegetation.
3. Australopithecus gracile.
Australopithecus afarensis.
Australopithecines, who lived 4–2.5 million years ago, were called “gracile” (from the Latin “gracio” - “graceful”). All skeletal parts from many individuals have been found from these amazing creatures, so reconstructions of their appearance and way of life are very reliable. Gracile australopithecines were upright creatures up to 1.5 m tall and 50 kg in weight. Their gait was somewhat different from the gait of a person. Apparently, Australopithecus walked with shorter steps, and the hip joint did not fully extend when walking. The arms were somewhat elongated, and the hands were still adapted for climbing trees. During the day, Australopithecines roamed the savanna or forests, along the banks of rivers and lakes, and in the evening they climbed trees. Australopithecines may have used sticks and rough stones as tools. Australopithecus afarensis is the most likely ancestor of the human line of evolution.
Australopithecus africanus.
Australopithecus africanus had a more advanced skull structure than Australopithecus afarensis, but overall a more archaic skeleton. The body proportions appear to have been intermediate between chimpanzees and modern humans. The height was from one to one and a half meters, weight - from 20 to 40 kg. The big toe probably had considerable mobility. The pelvic bones, in the vast majority of features, are closer to the human version than to the pelvis of great apes. It is the shape of the pelvis that is the most powerful argument confirming the bipedal mode of movement of Australopithecus. The structure of the teeth (the inclination of the incisors and canines and their small size) also distinguishes Australopithecus africanus from the great apes, making it more human-like. The structure of the brain, judging by its imprints on the inside of the skull, is close to that of chimpanzees and quite far from modern humans.
Australopithecus sediba.
This creature, which lived about two million years ago, although it is considered an australopithecus, “accumulated” quite a few human features: slightly protruding cheekbones, the shape of the nasal bones, small molars, some structural features of the brain, hands, and pelvis. In terms of the totality of its characteristics, Australopithecus sediba occupies a strictly intermediate place between Australopithecus and early representatives of the genus Homo (humans). In fact, it is not even clear to which genus it should be classified - the australopithecine and human features are so evenly distributed in its structure. Interestingly, the discovery of the remains of Australopithecus sediba was made using the popular Google Earth service, which made it possible to identify numerous caves in one of the regions of South Africa, in one of which the first finds were made.
Australopithecus gari.
"Gari" means "amazing" or "surprise" in Afar. Along with the remains, primitive tools dating back to 2.5 million years ago were found. This means that Australopithecus gari began to use stone tools almost before Homo habilis. Also, antelope bones with incisions were found, which suggests that Australopithecus hunted. He could well have developed into his intelligent form. We don’t know what prevented him. Judging by the dating and specialized features, it was not our direct ancestor. The height of the gary is 1.2–1.5 m, the brain volume is about 440 cm3. The size of its front teeth exceeds those of any other Australopithecus species.
Kenyanthropus flat-faced.
A specialized species of hominid. It existed 3.5–3.2 million years ago in parallel with Australopithecus afarensis and was generally similar to them, differing, however, in its significant width and flattened face. In some layers with the bones of Kenyanthropus, large and extremely primitive tools were discovered. Thus, Kenyanthropus was the first creature to make stone tools. There are almost a million years between them and the tools of our direct ancestors. Judging by the size and shape, Kenyanthropus's tools were not used for cutting meat, but for splitting something hard.
5. Australopithecines are massive.
Paranthropus massive.
Paranthropus were large, weighing up to 70 kg, herbivorous creatures that lived along the banks of rivers and lakes in the dense thickets of South Africa 2.5–0.9 million years ago. A distinctive feature of Paranthropus is its very large jaws with huge chewing teeth. Their lifestyle was somewhat reminiscent of the lifestyle of modern gorillas. However, they retained their bipedal gait. These creatures may have used bone tools to fish for termites.
Paranthropus Ethiopian.
This is the oldest of the massive australopithecines and the only one among this group that had sharply protruding jaws. The skull of Paranthropus Ethiopian combines primitive features that bring it closer to early and gracile australopithecines, and specialized features of massive australopithecines. Paranthropus ethiopicus is the probable ancestor of the later East African massive australopithecus, Paranthropus boyce.
Beuys' paranthropus.
With a height of up to one and a half meters, Boyce's Paranthropus could weigh up to 90 kg. On its skull, huge jaws and large bone ridges, which served to attach chewing muscles, are striking. In these australopithecines, the jaw apparatus reached its maximum development. The first discovered skull of this species even received the nickname “Nutcracker” due to the size of the teeth. Its diet probably consisted of a huge amount of tough, coarse fibrous vegetation.
5. Early Homo.
Rudolf Man.
The oldest man who had a large (compared to Australopithecus) brain (more than 700 cm3), and at the same time more massive and large-toothed than Homo habilis. About two million years ago, both species lived together in East Africa. Findings made in Kenya in recent years have made it possible to identify Homo rudolphinus as an independent species and clarify its position on the ladder of human evolution. Some scientists consider him a descendant of Kenyanthropus, others suggest a close relationship with Paranthropus.
A man from Dmanisi.
This is a species of early man described from remains found in Georgia. Hominids from Dmanisi are the oldest people to leave Africa (1.8–1.9 million years ago). In terms of brain volume, Man from Dmanisi is not much larger than gracile australopithecines. His “primitive” appearance is emphasized by a flat forehead, a huge eyebrow, and gigantic jaws protruding forward. One of the skulls found (an elderly man) was completely missing teeth (apparently, he was cared for and fed soft food; in this case, we are dealing with the oldest evidence of care for old and sick fellow tribesmen).
A skillful man.
Homo habilis (2.3–1.5 million years ago) was the first of our ancestors who began to regularly make stone tools and switched to omnivory. This is where the rapid growth of brain size begins. His skull became more rounded and high, the brain cavity became larger, the frontal bone became more convex, although tilted back. The jaws and teeth became smaller than those of Australopithecines, but were still larger than the teeth of later representatives of the genus Homo. Thus, an evolutionary tendency towards a general gradual reduction in the size of teeth is clearly manifested. The foot of a skilled person is almost indistinguishable from a modern one: the big toe is completely adducted to the rest. The foramen magnum is elongated, shifted forward at the base of the skull, which indicates upright posture. Homo habilis was the creator of the early pebble (so-called “Olduvai”) culture. It is sometimes identified as a late gracile australopithecus, but a number of progressive features in the structure bring it closer to later hominids. Habilis is the most likely ancestor of all later humans.
Naledi man.
Numerous bones of these ancient people were discovered by speleologists in a South African cave in 2013. A group of anthropologists who examined these remains described a new species of ancient people - Homo naledi. These people were small in stature (about one and a half meters) and had a rather large, albeit primitive in structure, brain (460–560 cm3). Also characteristic are very small teeth, a progressive structure of the hand and an almost human foot. The main problem is that it has not yet been possible to determine the age of this unique find, so the main discoveries related to Homo naledi are still ahead.
6. Archanthropes.
A working man.
Working man (1.8-1.4 million years ago) stood out among the early representatives of the genus Homo. Judging by the proportions of the skeleton (tall, long legs and narrow shoulders), he mastered a new ecological niche - savannas. The volume of the brain often reached the values of modern humans. The areas of the brain responsible for vision, memory, and coordination of movements developed rapidly. Speech abilities developed rapidly. They used fire and hunted.
Homo erectus (Africa).
Homo erectus (Homo erectus) is the most massive representative of ancient people. Although already undeniably human, Homo erectus was still very different from modern humans, so many anthropologists are inclined to identify a special kind of Pithecanthropus for them. Erectus appeared in East Africa and spread widely across Eurasia through the Middle East, reaching Indonesia in the east and Spain in the west. At the same time, the population, apparently, was concentrated in the southern regions and did not go beyond the subtropical zone. Apparently, there were at least two main geographical branches of these hominids - Western or Afro-European and Eastern or Asian. Homo erectus differed from later hominids mainly by a noticeably lower skull and details of the facial structure. Creators of the early and middle Acheulean culture of stone tools.
Sinanthropus.
This is the Asian form of Homo erectus, numerous finds of which have been made in the Zhoukoudian Cave near Beijing. Judging by the abundance of materials, ancient people lived in the cave for hundreds of thousands of years. It is interesting that the skulls in the upper layers of the cave are more progressive than in the lower ones: local evolution took place here. Sinanthropus is the probable ancestor of the Asian Heidelberg man.
Man of Flores.
The Flores Island people are perhaps the most intriguing paleontological discovery of the 21st century. Dwarf people with tiny brains amaze with their bizarre appearance - extremely short stature (just over a meter), small brain (smaller than that of a chimpanzee), and disproportionately large hands. For these features, journalists dubbed Man of Flores a “hobbit.”
7. Paleoanthropes.
Previous person.
This species is known so far from only one locality in Spain. Most likely, Homo Anterior is the ancestor of Heidelberg Homo, and possibly the common ancestor of Neanderthals and Homo sapiens. He had large brow ridges, a long and low skull, a massive lower jaw without a chin and large teeth, like a Neanderthal. The face, on the contrary, was relatively flat and did not protrude forward, that is, it was similar to the face of a modern person. Height is 1.6–1.8 m, weight of an adult male is approximately 90 kg, brain volume is about 1000 cm3.
Heidelberg Man.
Between about 500 and 130 thousand years ago, different parts of the world were inhabited by people who were very different from each other. However, their special intermediate appearance allows them to be united under the general name Heidelberg Man. The shape of the brain of Homo Heidelberg speaks of dramatic progress in various areas (especially in the use of speech). He populated not only warm, but also regions with a temperate climate in Europe and Asia, which required a new level of adaptability, more active use of fire, the construction of dwellings, and the manufacture of new types of tools.
Helmei man.
Helmei man, who lived in Africa 500–130 thousand years ago, is an African form of paleoanthropes that does not have the specialized characteristics of European Neanderthals. They are often referred to as “archaic Homo sapiens.” Our direct ancestors. The structure of the skull of Helmei Man mosaically combines archaic and “sapient” features. Individual representatives of this species were no longer different from us, but on average they still had a more sloping forehead, a protruding eyebrow and large jaws. The first people to develop a mental protuberance. The Helmei people made real points and began making tools from bone.
Neanderthal man.
The most studied species of fossil people, described 150 years ago. They had many completely human features of structure and behavior, but were still noticeably different from us - including the significant massiveness of the skeleton and skull. Probably, many of their features were formed under the influence of the harsh conditions of the Ice Age about 70-60 thousand years ago. In some representatives, the brain volume exceeded the values typical for modern humans. Neanderthals may have interbred with modern humans, and modern non-African populations of Homo sapiens have between 1 and 4% Neanderthal genes.
Denisovan man.
A mysterious species, described based on DNA analysis from the phalanx of the little finger, found in Denisova Cave in Altai. It turned out that the lines of sapiens and the common ancestors of Neanderthals and Denisovans diverged first, and somewhat later the lines of Neanderthals and Denisovans diverged. In the period 20–40 thousand years ago, three “variants” of people lived in Altai and nearby regions: Denisovans, Neanderthals and typical sapiens. A study of the genome of ancient people from Denisova Cave showed that they (like Neanderthals) contributed to the gene pool of some populations of modern people.
8. Neoanthropes.
A reasonable man.
Homo sapiens (Homo sapiens) is the only living species of hominid. Time of existence of this species: 45 thousand years ago - modern times (sometimes the lower limit is pushed back to 160 thousand years ago or more). Since about 40-45 thousand years ago, people of modern appearance (except perhaps somewhat more massive than us) - neoanthropes - have been known almost throughout the entire planet: in Africa, Europe, Asia and Australia. Only America was settled later - according to the latest data, about 15 thousand years ago. The population of Europe, belonging to the modern species of people, who lived in the Late Paleolithic era (40-10 thousand years ago), is called Cro-Magnons (after the name of the Cro-Magnon cave in France, where important finds of human skeletons and tools were made in 1868). Cro-Magnons lived side by side with Neanderthals for 5 thousand years in a row. The process of the emergence of the modern human species (sapientation) consists of both biological restructuring (enlargement of the brain, rounding of the skull, reduction in the size of the face, the appearance of a chin protuberance) and sociocultural innovations - the emergence of art, symbolic behavior, technical progress, and the development of languages.
Markov A.V. "Human Evolution"
Sokolov A.B. "Myths about Human Evolution"
A huge achievement of the theory of anthropogenesis is the knowledge of the time of the appearance of the first human population - 2.5 million years ago. This happened in large areas of Africa: South Africa, Kenya, Tanzania, Ethiopia.
In general, now there is such an expression among specialists in anthropogenesis: everything is “out of Africa” - “everything is from Africa”. Whatever you take, each new stage appeared in Africa: apes, Homo habilis, and Homo ergaster.
For a long time, scientists believed that human evolution was more or less linear: one form replaced another, and each new one was more progressive, closer to modern man, than the previous one. It is now clear that everything was much more complicated. The evolutionary tree of hominids turned out to be very branched. The time intervals of existence of many species overlap greatly. Sometimes several different species of hominids, at different “levels” of proximity to humans, coexisted simultaneously. For example, in the relatively recent past - just 50 thousand years ago - there were at least 4 species of hominids on Earth: Homo sapiens, Homo neandertalensis, Homo erectus and Homo floresiensis.
Recent paleontological discoveries indicate that throughout human evolution, in all its periods, from the time of our common ancestor with primates to the most recent times, in each individual era coexisted simultaneously at least two or three very different species and even different families of hominids (“bush”), and it is still too early to draw a straight line through any of them to humans: it is not known through which points to draw it.
You cannot imagine evolution as a trunk, indomitably reaching towards some peak. Evolution is more like a giant bush.
The current picture of the development of the species Homo Sapiens is developed on the basis of paleontological data using modern molecular genetic methods. Careful analysis shows that several tens of thousands of years ago the size of the original population Homo Sapiens there were no more than 5000 breeding pairs. Then, apparently, this population divided into several groups, and each of the newly formed populations at one time passed through the so-called « bottleneck"- a period of exceptionally small numbers, when the number of breeding pairs could number only a few dozen.
Biological evolution of modern humanity
For a long time it was assumed that human evolution had stopped biologically, it did not go any further, and humanity was evolving further only in historical terms. Now it has been discovered that even such a system as the brain has continued to evolve, at least during the last century, and obviously continues to evolve and will continue to evolve. Moreover, this was done by our compatriot, Professor Savelyev, a famous brain specialist. The dental system is also evolving.
Genetic affinity of people
You can compare different people, for example, a native of America or Oceania and a person from Europe. They seem to be very different. DNA analysis can provide an objective characterization, an outside perspective. If you compare the DNA of different people, it turns out that they differ from each other by only one tenth of a percent, that is, only every thousandth of a nucleotide is different, and 999, on average, are the same. And moreover, if you look at the DNA of all the genetic diversity in people, in the most diverse representatives, it turns out that these differences are much smaller than the differences between chimpanzees in the same herd.
All people are genetic brothers and sisters. Such closeness and at the same time some difference is possible because our DNA contains approximately three billion nucleotides. Every thousandth makes a difference, so it turns out that three million of our nucleotides are different. True, most of them most likely fall on silent sections of DNA, and our genes, in principle, are largely the same.
A new refined evolutionary tree of the animal kingdom, based on the analysis of a record number of genes and types of animals, has made it possible to resolve many controversial issues of evolution and systematics. The theory was confirmed that the division into protostomes and deuterostomes occurred even before animals had formed a whole O m (secondary body cavity). Protostomes are divided into two distinct evolutionary lineages: Lophotrochozoa (flatworms, annelids, molluscs, brachiopods, nemerteans) and Ecdysozoa (roundworms and cephalopods, arthropods, onychophorans, tardigrades).
Until the last quarter of the 20th century, biologists reconstructed the evolutionary history of animals mainly on the basis of data from comparative anatomy, embryology and paleontology. Molecular data were then added to this list, the most important of which were DNA nucleotide sequences. Evolutionary reconstructions (“trees”) based on molecular data did not always match the old “classical” trees. This led to heated debate among zoologists.
At first, many were of the opinion that the old proven methods were more reliable than the newfangled molecular ones. But gradually the scales tipped the other way, and today most experts believe that molecular data in principle allow us to reconstruct the evolutionary paths of animals much more accurately than morphological and embryological characters. In Russia, however, many still do not agree with this, but in the West there are very few such “retrogrades” who do not trust molecular reconstructions.
Molecular “characters” (nucleotide sequences) have two important advantages over morphological ones. Firstly, there are simply many more of them. In fact, each nucleotide in a chromosome can be considered as a separate character - and thus obtain trees based on many hundreds and thousands of characters, while the number of morphological characters suitable for phylogenetic (evolutionary) analysis is usually limited to several dozen. Secondly, most morphological characters directly affect the viability of the organism, while substitutions of many nucleotides are neutral (indifferent). Morphological similarity does not necessarily indicate kinship - it can also develop in unrelated organisms under the influence of natural selection in similar living conditions (this phenomenon is called convergence). The convergent occurrence of similar nucleotide sequences is much less likely.
The problem, however, is that the reliability of any evolutionary reconstructions, including molecular ones, very much depends on the volume and completeness of the original data.
The main criterion for the reliability of molecular trees is their stability or repeatability. There are several different algorithms for constructing a tree based on the same array of initial data (for example, nucleotide sequences of a gene in several different organisms). If the use of different algorithms gives the same result, this indicates its reliability. Special procedures have also been developed for assessing the reliability of the “nodes” (branch points) of the resulting trees (see: bootstrapping).
The first molecular trees of the animal kingdom, based on single genes and a very small number of species, were characterized by low stability and therefore aroused little confidence. It quickly became clear that the more genes and groups of animals involved in the analysis, the more consistent and reliable the results became. Scientists, of course, began to scramble to increase the amount of data they use. Gradually, a picture began to emerge that was quite different from the “classical” one, based on morphology and embryology.
The most important of the identified differences concerned the related relationships between the main types of bilaterally symmetrical animals (bilateria). According to classical concepts, all bilateria that have a coelom (secondary body cavity) descend from a common ancestor and are contrasted with “pre-coelomic” bilateria, such as flatworms and roundworms. Coelomates are divided into protostomes (annelids, mollusks, arthropods, etc.) and deuterostomes (chordates, hemichordates, echinoderms). Annelids were considered the ancestors of arthropods.
Molecular data, on the contrary, showed that the division into two lineages corresponding to protostomes and deuterostomes occurred earlier, even before the development of coelom in bilaterians. O m. From this it followed that it was intact O m, which specialists in comparative anatomy considered the most reliable taxonomic character (the basis for natural classification), in fact developed independently in protostomes and deuterostomes. Roundworms that do not have a coelom, according to molecular data, turned out to be close relatives of arthropods (they were united in the group of “molding animals” - Ecdysozoa), and flatworms are related to mollusks, as well as annelids, the relationship of which with arthropods was not confirmed by molecular data. Flatworms (without coelom), as well as those with coelom O m mollusks, annelids and a number of other types were combined into the group Lophotrochozoa.
All these conclusions, however, could not be considered final until very recently. Molecular trees remained unstable. Some of them seemed to confirm the “old” version of animal evolution, in which the whole appeared only once (this version was called the “coelomate theory”). To resolve this controversy, the researchers gradually increased the volume and representativeness of the molecular data used in the hope that the resulting trees would eventually become stable.
A group of scientists from the USA, Denmark, Germany and Great Britain published in the latest issue of the journal Nature the latest version of the molecular evolutionary tree of animals, based on a record number of genes (150) and animal groups. The analysis included 77 species belonging to 21 animal phyla, with genomic data still missing for 11 of these phyla. Many parts (nodes) of the resulting tree actually turned out to be much more stable than in earlier studies of this kind.
The results obtained provide convincing evidence against the classical “coelomate theory.” The most “primitive” of the groups included in the analysis turned out to be ctenophores. Bilateria are first divided into lineages of protostomes and deuterostomes, and only then a whole is formed independently in each of these lines. O m. Protostomes are divided into Lophotrochozoa and Ecdysozoa. The closest relatives of arthropods turned out to be onychophorans and tardigrades (which corresponds to classical ideas), as well as roundworms (which does not correspond to them at all). The closest relatives of annelids turned out to be not arthropods, as previously thought, but brachiopods and nemerteans.
Much has become clearer, but the family ties of some groups remain unclear (their position on the new tree turned out to be unstable). These groups are not shown in the above figure (with the exception of sponges). The authors see the reasons for the instability in the fact that for some groups they were unable to collect a sufficient amount of molecular data (sponges, intestinal turbellaria, mysostomids), while others were represented by an insufficient number of species (bryozoans, rotifers). In addition, the authors were unable to include in the analysis Trichoplax, which, judging by the results of mitochondrial DNA analysis, is the most primitive of modern animals.
Tree of Life:
The very fact of the existence of the Tree of Life is surrounded by various conjectures: some believe that the tree is living, others that it is inanimate. In remote corners of the Internet, there is even a widespread version that the tree grows in India, and animal forms appeared on it miraculously without human intervention. To clear things up, let's look at Disney's press release:
The Tree of Life, designed to personify the interconnection of all life on the planet, is the result of the work of more than 12 craftsmen who created 325 carved animal figures. The tree is entirely artificial. The tree-supporting steel structure was designed using the same principle used to build offshore oil rigs. "The hardest part of creating the pieces was finding the balance between the animal shape and the tree shape," says Zsolt Hormay, chief sculptor and designer from Budapest, whose team included three Native American craftsmen, craftsmen from France, Ireland, Indianapolis and Central Florida. To achieve the effect of a smooth flow of one figure into another, the outer part of the trunk from which the figures were made was processed outside the park. Next, the entire trunk was divided into 10 huge segments and transported to the construction site in front of the park. There, the segments were paired together and transported by crane to the tree's current location, where all the pieces were reunited into one piece like a puzzle.
Construction of the Tree of Life:
The secret to the illusion of “woodiness” of the trunk and bark is the talented coloring of the outer part of the tree using many shades of brown and green. Each leaf was attached to the branches by hand, resulting in more than 103 thousand leaves of different shades, as well as four shapes and sizes.
In total, the tree took over 18 months to complete and required a team of a thousand people to complete the exterior of the tree.
Walking along a path around the tree's tangled roots, visitors can discover the entrance to the massive trunk and discover a 430-seat 3D cinema. The entrance between the roots can be seen by watching a video tour around the Tree of Life:
"The Tree of Life is a technological marvel, but it is also a symbol of the beauty, diversity and splendor of the animal world on earth," said Joe Rhode, vice president of simulation and chief designer of the park. “We want you to experience wonder and awe when you look at it, and then transfer this feeling to the real world of animals.”
Night view of the Tree of Life:
The animal kingdom is divided into two subkingdoms: unicellular and multicellular.
Single-celled organisms (eukaryotes) evolved from heterotrophic prokaryotes. In modern fauna these include rhizomes, flagellates, sporozoans, and ciliates.
Further development occurs from primitive turbellaria with the formation of annelids (oligochaetes, leeches, polychaetes). Primitive polychaete worms determine the emergence of four branches in the tree of animals.
The first branch is mollusks (gastropods, bivalves, cephalopods).
The second branch is arthropods (crustaceans, arachnids, insects).
The third branch is echinoderms (starfish, sea urchins and sea cucumbers).
The fourth branch is the chordates, which arise at the beginning of the Paleozoic, when all types of invertebrate animals (discussed above) already existed. Chordates evolved from a deuterostome, bilaterally symmetrical, free-swimming ancestor common with echinoderms.
The phylum chordates unites 3 large groups of animals: the subphyla of skullless, larval chordates and cranial, or vertebrates. The skullless subtype consists of one class of animals - cephalochordates, with a total of 30 species, for example, the lancelet. The subphylum larvalochordates (or tunicates) descended from primitive free-swimming skullless animals that switched to a sessile lifestyle. Tunicates are all marine organisms, with sea squirts among the best known.
The highest subphylum of chordates are vertebrates. Among the vertebrates, cyclostomes (jawless) are distinguished - these are lampreys and hagfish. From primitive cyclostomes evolved fish that are divided into cartilaginous, bony, lobe-finned, and lungfish. Lobe-finned fish gave rise to amphibians, or amphibians. Amphibians include tailed, tailless, and legless. For example, proteas, newts, salamanders and sirens; toads and frogs; fish snakes and caecilians. Reptiles, or reptiles, evolved from amphibians. The modern fauna includes orders of squamates (snakes, lizards, moths, chameleons), crocodiles, turtles and beaked animals (tutteria).
Birds evolved from unspecialized, climbing reptiles. Modern birds include groups of keeled, or flyers; swimming, or penguins; ratites, or running (ostriches, kiwi, cassowaries).
The ancestors of mammals are unspecialized Paleozoic reptiles with the structural features of amphibians, or animal-toothed reptiles. The first mammals diverged into two branches. The first branch is the proto-beasts (monotremes), for example, the echidna, the platypus. The second branch is marsupials (koalas, kangaroos, opossums), as well as placentals (shrews, bats, rodents, carnivores, pinnipeds, artiodactyls, equids, elephants, primates, humans). The human line begins to develop from the ancestral forms of insectivorous prosimians.
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