Where does an elephant's trunk come from and how does DNA work? History of proboscideans Formation of a long trunk in the ancestors of the modern elephant.
Oddities of Evolution 2 [Mistakes and Failures in Nature] Zittlau Jörg
Without a trunk: elephants without control
Actually, the evolution of the elephant was nothing more than a constant desire for new achievements and subsequent attempts to cope with the consequences of these achievements - until, in the end, what happened was achieved. To some extent, the elephant is living and grotesque proof that evolution quite often corrects its own mistakes.
At the beginning of elephant evolution there was probably a "decision" to be larger than all other land animals on this planet. An adult elephant weighs up to 7 tons and is twice the size of a rhinoceros or hippopotamus with its wide mouth. The advantage of this huge size is energy savings. This corresponds to the laws of physics: if the radius of a ball doubles, its volume increases eight times, but its surface area increases only four times. The disadvantage of such a huge size is that these 7 tons, even if they actually serve to save energy, need to be “powered”. Since the elephant is also a herbivore - with its slowness, it would not have the slightest chance of killing any animal during the hunt and getting protein - it must eat a lot. A male elephant sometimes destroys up to 300 kilograms of plant food per day! This requires a strong jaw. Each of the four molars of an elephant is 35 centimeters long and can weigh several kilograms, and the tusks sometimes reach a length of three meters. In the exhibition of the Natural History Museum in London you can see the tusks of a male elephant that was killed in 1897 on the top of Kilimanjaro: their total weight reaches 200 kilograms!
It is clear that the already massive head of an elephant with a set of teeth weighing a hundredweight would be too heavy for the ordinary neck of a vegetarian like a horse or gazelle. And then evolution came to the rescue again, giving the elephant a short and thick neck. However, this again brought problems, since with such a neck it is impossible to tilt his head to the ground to pluck herbs. A creative solution was required. Then evolution created an extremely mobile trunk three meters long. At the end of its development, the animal began to resemble a creature from another planet. Having introduced elephants into his army, Hannibal easily horrified the brave Romans: huge, short-necked, with a long nose and tusks with which they could scratch the heels of their thick legs.
Even the sail-like ears are the result of another attempt at evolutionary correction. Obviously, the elephant's body has become too large, and he lives not in cold Central Europe, but near the equator. Therefore, evolution had to create an additional surface for heat removal, namely huge ears.
The logical result: the modern appearance of the elephant familiar to us is the result of a series of endless mistakes and attempts to correct them. It's very difficult! On the other hand, it should be noted that the costs were worth it: elephants not only look unique, they are also uniquely smart. It is no coincidence that the “colossal memory of elephants” has become a proverb. They are sometimes called "sound machines" and "communication geniuses." A female elephant in Kenya's Tsavo National Park spends hours imitating the rumble of trucks passing on the highway between Nairobi and Mombasa, three kilometers away. She probably invented a hobby for herself so as not to suffer from loneliness. Her brother Calimero, a 23-year-old male from the Basel Zoo, also practices imitation: he chirps. He has been living with two Asian elephants for 18 years now and has adapted to the “dialect” of his cohabitants. The elephant has mastered the “chirping” language of its females so much that it rarely uses the sounds inherent to its own species to communicate.
Elephants also have a sense of humor. Zookeepers say that the elephant’s trunk can push them into the pool or into the feeder with food. Many visitors return home soaking wet, as the thick-skinned pranksters like to spray them with water from their trunks. Visitors swear that they saw a pleased gleam in the elephant's eyes. However, as often happens, intelligence is a double-edged sword, and advantages are just a continuation of shortcomings. Not only for the elephants, but also for the world around us.
Thus, intelligent animals are distinguished by the fact that they are very sensitive and susceptible to frustration, which can cause aggressive behavior - which is why good-natured giants often turn into frantic monsters. Researcher Heini Hediger, who died in 1992, wrote: “For every male elephant kept in a zoo, there is one dead zookeeper.” Hediger knew what he was talking about, since he directed zoos in Bern, Basel and Zurich. The statement still holds true because time and time again zookeepers have died in elephant cages. The European Elephant Society warns: “Elephants are the most dangerous wild animal in captivity,” as no other animal has claimed so many human victims to date.
In India, incidents often occur with working elephants freed from their chains. A good-natured giant who voluntarily agrees to become a slave and work for the good of man is nothing more than a legend: the situation significantly depends on how well the animal feels in its captivity. Elephants also show aggressiveness in the wild. So, in 2005, Bunyaruguru, a village in Western Uganda, received a not at all friendly visit from a herd of enraged elephants. The residents looked at the ruins of their home village in confusion - they had never had problems with gray giants before. However, this was not the worst thing; the worst thing happened later: elephants began to block the streets and hunt people. The reason for this inexplicable “madness” is frustration. Young males who were driven out by adult elephants were “bullying.”
Sometimes the culprits of the “rabies” are poachers, since they shoot individuals with the largest tusks, and these are, as a rule, animals that play a leading role in the social association of elephants. After the death of the leaders, the herd remains confused for a long time and is capable of “rash” actions.
Frustration and sexual ignorance were the result of 42 rhinoceroses that were found dead in Pilanesberg National Park in South Africa a few years ago. They, as confirmed by random video recordings, became victims of young male elephants who were released into the park unattended. When they tried to mate with rhinoceroses, they rebuffed them (not to mention the fact that this “procedure” could not work in principle). And the rhinoceroses were beaten to death by stronger tusk owners.
Elephants can be so cruel, and their attitude towards their dead relatives is so touching, which is practically not typical for other species of animals. Elephants experience obvious excitement upon discovering the remains of their brothers, sniffing and feeling them with their trunks and touching them with their feet. Based on observations of such unusual behavior, the assumption arose that animals visit their deceased relatives, just as a person does when coming to a cemetery to remember his buried grandmother. A natural question arises: why? Since from the point of view of evolution, the cult of ancestors, in fact, does not give anything.
Biologists from Kenya and England decided to try to uncover this secret and conducted a series of experiments: they laid out various parts of the skeletons, among which, along with the remains of elephants, there were also the skulls of dead buffaloes and rhinoceroses, and the skull of their deceased leader (the life of an elephant family is organized by the “main” elephant) . The result of the study showed that elephants are mainly interested in the bones of their brothers; the skulls of dead rhinoceroses and buffaloes are less interesting to them. Before you hastily say, “Well, that’s clear,” think about whether you yourself could easily distinguish a human skull from a monkey’s skull. The elephant, in any case, manages to catch such subtle differences - and thereby emphasizes his intelligence once again.
What's even more remarkable, however, is which remains the elephants found most interesting. Tusks! "Perhaps it's because the tusks remind elephants of living animals," explains study leader Karen McComb from the University of Sussex. Touching each other's tusks with their trunks is one of the greeting rituals, because elephants are social animals. Thus, the elephants became interested not in the skull of their leader, but in the remains of other elephants. This means that elephants have no cult of ancestors! Research in recent years has proven that “elephant cemeteries” - places where elephants, sensing the approach of death, go to die, but which almost no one has ever seen - are also a myth. The accumulation of elephant skeletons can be explained more likely by periods of drought in these places or by the fact that the animals were killed by hunters.
But the question remains: why are elephants still not indifferent to the remains of their brothers? Maybe smart animals study comparative anatomy? Or is this simple entertainment for looters? Biologists from Karen McComb's group could not definitively answer this question. This is fair on their part, since they do not try to find an evolutionary explanation for unexplained behavior, as other biologists and researchers do. They state: “Even if the behavior of elephants differs significantly from human behavior in respect of veneration of the dead, it is still unusual and worthy of attention.” We must also look calmly and with respect at the fact that some “oddities” of certain species of animals remain incomprehensible to us.
From the book The Vanished World author Akimushkin Igor IvanovichElephants and mastodons In Egypt, in the oasis of the Fayoum province, not far from the city of Illahuna (about a hundred kilometers south of Cairo), Lake Birket-Karun glistens in the sun - all that has now survived from the once famous Lake Merida. Mer-ur is a great canal, it was called in
From the book Fundamentals of Neurophysiology author Shulgovsky Valery ViktorovichDESCENDING MOTOR CONTROL SYSTEMS Physiology of descending pathways from the cerebral cortex. In the evolution of the brain, the area of the cerebral cortex noticeably increases. As a result, higher mammals, including primates, develop a cloak that
From the book Seeds of Destruction. The secret behind genetic manipulation author Engdahl William Frederick“Second only to atomic weapons control...” John D.'s third forced sterilization program was by no means a radical departure from shared family interests. The Rockefellers had long regarded Puerto Rico as a convenient human laboratory. Back in 1931
From the book The Newest Book of Facts. Volume 1 [Astronomy and astrophysics. Geography and other earth sciences. Biology and Medicine] author From the book Anthropological Detective. Gods, people, monkeys... [with illustrations] author Belov Alexander IvanovichWHERE DID THE ELEPHANTS GO? If you can joke about a pig that it is a human ancestor, you can’t say the same about elephants. The entire elephant appearance is so unique that the similarity is difficult to discern at first. Only the Indian deity Ganesha has the head of an elephant and the body
From the book Fundamentals of Psychophysiology author Alexandrov Yuri4. INFLUENCE OF EMOTIONS ON ACTIVITY AND OBJECTIVE METHODS OF CONTROL OF A PERSON’S EMOTIONAL STATE The very fact of generating emotions in a situation of pragmatic uncertainty predetermines and explains their adaptive compensatory value. The point is that when
From the book The Newest Book of Facts. Volume 1. Astronomy and astrophysics. Geography and other earth sciences. Biology and medicine author Kondrashov Anatoly PavlovichWhy don't elephant seals suffer from decompression? Elephant seals are excellent divers. On average, this animal dives underwater for 20 minutes, diving to a depth of about 500 meters. Some “record holders” reach a depth of one and a half kilometers and can stay under water
From the book Stop, Who Leads? [Biology of behavior of humans and other animals] author Zhukov. Dmitry AnatolyevichWhims - the subjectivization of control Bruno Bettelheim, analyzing the existence in the labor camp of Nazi Germany, pointed out that in order to prevent learned helplessness, one must do everything that is not prohibited. For example, brush your teeth, do exercises. Others
From the book The Mystery of God and the Science of the Brain [Neurobiology of Faith and Religious Experience] by Andrew NewbergReligion and the Sense of Control It is quite obvious that the benefits of faith for body and soul are due to the values that religion supports. Perhaps most importantly, religion helps alleviate existential stress because it gives us a certain
From the book Amazing Paleontology [The History of the Earth and Life on It] author Eskov Kirill YurievichCHAPTER 6 Late Precambrian: the emergence of multicellularity. Oxygen control hypothesis. The Ediacaran experiment Before directly embarking on the study of the most ancient multicellular organisms, let's think: why, in fact, this
From the book Animal World author Sitnikov Vitaly Pavlovichmocking expression “Russia is the birthplace of elephants” arose back in Soviet times in the late 1940s. Then a whole campaign against pro-Western sentiments and “rootless cosmopolitans” unfolded in the country. One of the manifestations of this struggle was a fierce desire to attribute many scientific, technical and cultural priorities to either Russia or the USSR (they say that it was our people who were the first to invent the airplane and bicycle, the law of conservation of energy and even the theory of relativity). The storyteller E. Schwartz spoke well about the next unbridled surge of “patriotism”:
“Do you know why “Dragon” (his play - S.K.) was banned? The city is liberated by a certain Lancelot, who assures that he is a distant relative of the famous knight, beloved of Queen Guenievre. Now, if instead I had shown Titus Zyablik, a distant relative of Alyosha Popovich, everything would have been easier...”
It must be said that this trend was not original. The desire to spur one's exclusivity in similar ways can be observed in almost all countries (for example, in Turkey during the time of Ataturk). Moreover, after the collapse of the Soviet Union, the intensity of the nationalist “trash and frenzy” only intensified and acquired the character of complete anti-scientific nonsense. Suddenly it turned out that it is your nation that stands at the foundation of world civilization, has the most ancient and correct language and attitude to all great achievements.
A still from the film “The Koloboks Are Conducting the Investigation.”
Well, this is what we see every day. Another funny thing is that there really were elephants in Russia, and in huge numbers. However, they were found on almost all continents - with the exception of Australia and Antarctica, which broke away early. Modern elephants are just pitiful remnants of the former greatness of the proboscis order.
It started, as always, small. Somewhere 40 million years ago (during the late Eocene), the ancestors of proboscideans called Meriteria lived in Africa. They bore little resemblance to their descendants - they were no larger than a pig, instead of a trunk they had an elongated snout, and instead of luxurious tusks, they had only noticeably protruding incisors (and on both jaws at once). Apparently, the first proboscideans led an amphibious lifestyle, like hippopotamuses (perhaps these conditions stimulated the extension of the nose as a breathing tube).
Meriteria.
A later representative of proboscideans, the Oligocene Platybelodon (in our opinion, “shoveltooth”), also led a similar lifestyle. It had already reached a height of 3 meters, and the incisors on the lower jaw really resembled horizontal blades, with the help of which it apparently dug out and raked up aquatic vegetation.
Platybelodon.
At the same time, mastodons roamed the land, already reminiscent in their appearance of the usual elephants. They had a massive, highly elongated skull, an impressive trunk and protruding tusks, which were also preserved on the lower jaw (though they were smaller there).
Mastodons.
One of the most unusual proboscideans was Dinotherium (“terrible beast”), living in the Miocene and Pliocene eras. He looked quite elephantine, and the only “terrible” things about his appearance were his size (up to 4.5 m in height) and remarkable tusks. For some reason they grew only on the lower jaw and stuck out not forward, but downward - almost at a right angle. Scientists still don’t really know why Dinotherium needs such a “rake.”
Dinotherium.
The peak of the proboscis heyday occurred in the Pleistocene. During this era, the order reaches such a wide distribution and species diversity that it is not without reason that it is called the “age of elephants.” At the same time, proboscideans reach their maximum size. Today it is believed that the largest land mammal in the history of the Earth was not the hornless rhinoceros Indricotherium, as previously believed, but an elephant called Palaeoloxodon namadicus. Based on the found hip, scientists estimated the height of paleoxodon to be 5.2 m and its weight to be 22 tons (i.e., the same as 3-4 modern African elephants).
Palaeoloxodon namadicus.
However, the most famous and “promoted” prehistoric proboscis remains to this day woolly mammoths(it’s enough to remember the “Ice Age” cartoon series). Firstly, these elephants have been very well studied - their remains are found in abundance in Europe, North America and especially Siberia. Thanks to this, Russia even became one of the ivory exporting countries (especially after the ban on hunting African elephants). And the word “mammoth” itself passed into other languages from Russian. Linguists put forward different theories about its origin. For example, that at first it came from the Mansi “mang ont” (“earthen horn”), and then became closer in sound to the name of the Christian saint - Mamant.
Woolly mammoths.
No matter how they tried to explain the origin of these bones in ancient times! The indigenous peoples of Siberia considered them to be the remains of a giant deer, which fell into the ground up to its chest and, thus wandering, paved river beds. Those familiar with the Bible argued that this was a beast that did not fit into Noah's ark. Well, some Christians even passed off mammoth bones as the relics of saints - for example, the tooth of St. Christopher or the thigh of St. Vincent.
The permafrost perfectly preserved not only the bones of mammoths, but also entire carcasses. In the hall of the St. Petersburg Zoo Museum you can still see a stuffed so-called. “Beryozovsky” mammoth, discovered in Yakutia on the banks of the Berezovka River in 1900.
Stuffed Berezovsky mammoth.
And already in my childhood, the discovery of the Kirgilyakh mammoth, better known under the nickname “Baby Mammoth Dima,” created a lot of noise. The fact is that this unfortunate cub, discovered in 1977 in the Magadan region, preserved not only soft tissues, but even red blood cells and stomach contents.
Mammoth Dima.
Perhaps it was this find that served as a source of inspiration for the creators of the cartoon “Mother for the Baby Mammoth” (1981) with the well-known song by Vladimir Shainsky.
“Baby Mammoth Dima” was considered the best-preserved specimen of a mammoth until 2007, when “Baby Mammoth Lyuba” was found on the Yamal Peninsula. There were even a few strands of reddish fur left on her body.
Baby mammoth Lyuba.
Joke:
Three mammoths are grazing, and then a herd of elephants appears in the distance. One of the mammoths raises his head:
- Guys, atas are skinheads!!!
Yes, mammoths were very furry animals. Which is understandable if we remember that they lived in an era of sharp cooling, when the cap of polar glaciers began to advance on the continents. Amazingly, these large (up to 4 m in height and weighing 10-12 tons) creatures managed to adapt well to the “Great Winter”. Their ears became smaller, but thick hair grew on their body, a solid layer of fat formed under the skin, and a hump of fat appeared on their back. Another distinctive feature was the very high skull with a characteristic rounded top.
Mammoths lived in forest-tundra conditions, where they ate steppe grasses and tree branches. And the huge four-meter tusks apparently helped these animals tear off bark and tear apart snow in search of food.
Mammoths.
It is generally accepted that mammoths greatly helped our primitive ancestors in the harsh conditions of the so-called. "Ice Age". Few doubt that people hunted these giants. But we can only speculate about the methods and scope of this hunt. The popular belief about the massacre of mammoths, which led the species to extinction, is probably an exaggeration. Even armed with a “firearm,” hunters did not manage to “zero” African elephants in two centuries. What can we say about people whose most effective hunting trick could only be a dug hole.
Drawing of a Paleolithic mammoth (from the Rouffignac cave).
Among other reasons for the extinction of woolly mammoths, scientists name an epidemic, genetic degeneration, a sharp change in the food supply due to climate warming, and much more. One way or another, about 10 thousand years ago these northern giants almost completely disappeared. Although in some places (for example, on Wrangel Island) the species of dwarf mammoth still survived, which became extinct later - about 4 thousand years ago. Some even believe that it was the skulls of dwarf mammoths, which were once found in Sicily and Crete, that gave rise to legends about one-eyed giants - Cyclops (the large nasal cavity in the skull could be mistaken for an eye socket).
The “Age of Elephants” is over, and today only two species live on Earth - African and Asian (or Indian). Despite the general similarity, even a child can distinguish them.
Let's start with the fact that the African elephant is larger than the Asian one (the first has a maximum height of 4 meters and a weight of 7 tons, the second has a maximum height of 3 meters and a weight of 5 tons). This difference is due, first of all, to the fact that the first species lives mainly in the open areas of the savannah, while the second prefers to wander through the forests. However, African elephants also have a subspecies that prefers forest life. Therefore, it is also smaller than its steppe counterpart (up to 2.5 m at the shoulders).
Female African forest elephant with calf.
If we come across representatives of two species that are similar in size, then we need to look at the head. The African species is much more protruding, while the Asian one has smaller ears, more pointed in shape, and their ends never touch each other. Male Asian elephants have much shorter tusks (up to 1.5 m), while females, as a rule, have no tusks at all. The trunk has one growth at the end, while the African species has two. In addition, the Asian’s skull has a noticeable elevation, which makes him look “brow-browed and smarter” than the African.
Asian and African elephants.
Den Den (letter to the Editor): I would like to ask three questions that arose after visiting the Museum. Darwin in Moscow: 1) How do scientists determine whether the first creatures on earth are predators or non-predators, traces of which remain only in fossils (there is no way to determine by teeth, as I understand it)? and what evolutionary factors contributed to the emergence of predators or non-predators from simple single-celled organisms? 2) As I understand it, there were two large extinctions of creatures - and what was the reason for the first extinction? (by the second I mean the extinction of dinosaurs). 3) The ancestors of living animals were very surprised - what factors contributed to the growth of the elephant’s trunk? Need to water yourself in hot weather and get food from trees? Thanks in advance for your answers!
Stanislav Drobyshevsky:1) There are a huge number of modern creatures that eat in a variety of ways. By comparing ancient remains with modern known ones, one can learn about nutrition even from footprints, phalanges and ribs. Sometimes not so much is retained, and the oral apparatus is more or less established, so the type of nutrition can be determined. Factors in the occurrence of predation are the availability of a resource, that is, those who can be eaten. If there is food available, sooner or later there will be someone who will eat it. Being a predator is beneficial in its own way, because you can get a lot of calories at once.
2) As I understand it, you are talking about the Permian-Triassic extinction. You can read in detail about its reasons in Eskov’s book “Amazing Paleontology”. And the short gist is this: continents from a single Pangea began to spread out, the climate began to change, and besides, insects with aquatic larvae appeared, which carried phosphorus and other trace elements from the waters to watersheds. At the same time, plants emerged with normal roots that anchored the soils, preventing them from flowing back into the waters. In total, this led to a phytoplankton crisis (algae lacked microelements), hence the zooplankton crisis, hence the extinction of all higher trophic levels.
3) The ancestors of elephants looked like something like a tapir; with their lack of care, they raked aquatic plants into their mouths. Further - more, the trunk turned out to be a very useful multifunctional tool, and so it grew to its current splendor.
Vadim: Please explain/correct: the main (only?) carrier of hereditary information, the DNA chain (at least the genes in the coding part) can be associated with a description of a set of building blocks proteins (or instructions for their manufacture) from which an organism is built. Where and how in the zygote is the information about when, where and what proteins are required, i.e. architectural diagram of the future organism, program of gene expression (on/off), cell differentiation, etc.? In DNA? How is it possible to encrypt an insanely huge amount of information about the structure of an organism from trillions of complexly interacting cells in several billion virtually binary values? Thank you.
Svetlana Borinskaya: The body's development program, encoded in DNA, does not work by itself. To implement it, we need “triggering” signals that come from the cell and from the external environment (for mammals, signals from the outside go through the mother’s body). "Architecture" is determined by the sequence of gene activation. And this sequence, in turn, is determined by signals from other genes and from the cytoplasm of cells. Signals can come in the form of regulatory proteins that bind to DNA and turn genes on or off, or in the form of special small RNA molecules (microRNAs) that do not encode proteins but are involved in regulating the processes of their synthesis. The development process is not strictly determined, it is probabilistic and based on commands “if...” => “do this.” “If” means the concentrations of proteins, microRNAs and some important metabolites in cells, the presence of certain signaling molecules, and “do so” means turning on/off certain groups of genes. The operation of specific sets of genes leads to cell growth, differentiation and morphogenesis (the movement of cells, as well as the programmed death of desired groups of cells).
Consistent, more or less coordinated implementation of commands leads to the formation of a body diagram.
More details can be found in textbooks, for example Gilbert S. Developmental Biology in (3 volumes), his text is available on the Internet.
Letter to the editor: A short question to Alexander Markov - what, in his opinion, are the reasons why the human brain began to shrink over the last 20 thousand years, and most importantly, how, with the help of what selection mechanism, in his opinion, could this happen? Could this process be influenced by the difficult human birth compared to animals? And is childbirth really more difficult in humans and more dangerous for the mother’s life than in other mammals?
Alexander Markov: I can’t speak for all mammals, but it’s definitely more difficult and dangerous than other great apes (see, for example:
Karen Rosenberg, Wenda Trevathan, 1995. Bipedalism and human birth: The obstetrical dilemma revisited). Theoretically, this circumstance could favor selection for smaller brains, as well as selection for having children at earlier stages of development. In addition, a large brain requires large energy expenditures for its work, and most importantly, for its development. This leads to an increase in the burden on parents, and, accordingly, to a decrease in the average number of children that a pair of parents can raise. Therefore, we would expect that if for some reason the positive effect of a large brain on fitness (i.e., survival and reproductive efficiency) is reduced, then the brain will shrink.
I outlined my thoughts on the possible causes of brain shrinkage over the last 20-30 millennia in the book “Human Evolution” (volume 2, chapter 4). Here's a quote from there:
"...As long as there are not very many memes in the environment, intelligence sharply increases competitiveness. However, the advantages of high intelligence are smoothed out when the environment is saturated with easily accessible memes. An evolutionary reduction of intelligence can also occur in the case when the dependence of reproductive success on the number of acquired memes becomes weaker ... According to the authors, both are observed in modern humanity. Therefore, there is every reason to expect that if there is an evolution of the mind in the human population now, it is not directed towards becoming wiser, but just the opposite.
As sad as it may be, this model prediction is confirmed by anthropological data. Record average brain volumes were achieved by sapiens at the beginning of the Upper Paleolithic (about 40–25 thousand years ago). From then until today, the average volume of the human brain has changed, if at all, in the direction of decrease. According to S.V. Drobyshevsky, about 27–25 thousand years ago, the average volume of the human brain began to decrease. Starting 10 thousand years ago, this trend became especially noticeable. This may be partly due to climate change, since our species “has, although not strict, a clear pattern of increasing body length and brain mass during periods of glaciation and decreasing during periods of warming” (Drobyshevsky, 2010). 10–12 thousand years ago, the next interglacial period just began - a warm period between glaciations. But another interpretation is also possible. The Upper Paleolithic “cultural revolution” led to a dramatic increase in the amount of useful information passed down from generation to generation through cultural inheritance. In other words, people began to receive much more valuable knowledge and skills from their parents and fellow tribesmen. The cultural environment became so saturated with useful memes that in the future, people apparently no longer needed such high intelligence as before to survive and reproduce successfully. If you don’t need to figure out everything with your mind and adults spoon-feed you a huge amount of ready-made useful knowledge in childhood, then you can get by with a smaller brain, since it is such an expensive organ. The same thing can be formulated in a more optimistic manner: thanks to the development of culture, people began to use their brain more efficiently, and therefore its mass became less important than the “quality of content”. In addition, as labor specialization developed, knowledge and skills were distributed among community members. You don’t have to remember everything yourself if you can ask a “specialist” at any time. All this could lead to the fact that the evolutionary trend toward brain enlargement, which began over two million years ago, went into reverse with the rise of culture."
Vadim: Please tell me if there are articles, studies, scientific works or at least some reliable information about the connection between geography and blood groups of representatives of different countries / nations / archaeological finds of ancient people and an analysis of this connection.
Svetlana Borinskaya: Research into the geography of the distribution of blood groups was started by the Hirschfeld spouses during World War I. They determined the blood type of the soldiers and at the same time asked where they were from.
In the 1950s, the English researcher Arthur Mourant created an atlas of frequencies of different blood groups in the population of different countries, which is considered a classic work: Mourant A.E., Kopec A.C., Domaniewska-Sobczak K. (1976) The distribution of the human blood groups and other polymorphisms. London: Oxford University Press. 1055 p. (first edition in 1954)
L.L. Cavalli-Sforza, one of the most famous population geneticists in the world, used Murant’s data in his book “The History and Geography of Human Genes” (Cavalli-Sforza LL, Menozzi P, Piazza A (1992) The History and Geography of Human Genes. New Jersey: Princeton University Press. 413 p.)
Blood typing is now moving from serological methods to direct DNA analysis, so we can expect more detailed genetic data to become available. However, even without this, blood groups are among the most studied human characteristics at the population level.
For the population of the former USSR, information on the distribution of blood groups is summarized in the book “Gene pool and genogeography of population” (Edited by Yu.G. Rychkov). Volume 1. Gene pool of the population of Russia and neighboring countries. SPb.: Science. 2000. 611 p.
Examples of determining blood groups by DNA in ancient remains:
Halverson MS, Bolnick DA. An ancient DNA test of a founder effect in Native American ABO blood group frequencies.
Am J Phys Anthropol. 2008 Nov;137(3):342-7. ABO blood group Sato et al. Polymorphisms and allele frequencies of the ancient DNA gene among the Jomon, Epi-Jomon and Okhotsk people in Hokkaido, northern Japan, revealed by
analysis. J Hum Genet. 2010 Oct;55(10):691-6.
Ivan Grukhin: Modern measurement methods (such as an accelerator mass spectrometer, for example) make it possible to determine the radioactivity of a sample quite quickly, within hours. However, before the measurement itself, it is necessary to prepare the sample. In the case of radiocarbon dating, it is necessary to separate the carbon of the sample from foreign carbon that got into the sample while it was in the ground for thousands of years. And then this carbon should be converted into a form suitable for a measuring device (for example, graphite). For different materials, sample preparation methods are different, and the time that such preparation takes is also different. For bones, for example, it averages about a month. For luminescence dating methods, it is important to isolate a mineral with suitable properties, such as quartz. This allocation can also take weeks. Each dating method has its own characteristics, but the general rule is that the measurement itself takes place relatively quickly (hours to days), but sample preparation takes a much longer time (weeks).
Perhaps no animal in the world has been as offended as the elephant. These giant herbivores are the largest inhabitants of land, but? Almost nothing. Let's start with the fact that many mistakenly attribute the mammoth ancestor to elephants. But this is fundamentally wrong. Mammoths, mastodons and elephants are completely different families. And who is part of the elephant family? Let's figure it out.
1 Erytherium (60 million years ago)
The ancient ancestors of elephants were by no means such giants. And their trunk was only in outline. The very first pro-elephant that scientists discovered was erytherium. A completely small animal weighed up to 5 kilograms. It was possible to identify it only from individual fragments of the jaw, but this was enough, because it is the teeth that serve as a distinctive feature of proboscideans.
2 Phosphateria (57 million years ago)
Phosphateria is the next in line of the great-great-great of our gray giants. And it is already noticeably larger: from those fragments that have been preserved from the distant times of its existence, one can determine its height (no more than 30 cm) and weight (up to 17 kg). Scientists came to the conclusion that the animal was an omnivore.
3 Meriteria (35 million years ago)
A semi-aquatic animal that lived along the edges of reservoirs, Meriteria, which already had the beginnings of a trunk and long divided incisors, from which elephant tusks are then formed. And yes, they were larger - they weighed up to 250 kg, and reached 1.5 meters at the withers.
4 Bariteria (28 million years ago)
Up to three meters high, with a large skull and fairly developed fangs protruding from under the nose-trunk - if you met a barytherium, it would definitely scare you. Just look at the cost of the fangs, from which in the future tusks will develop, protruding from both the lower and upper jaws - obviously not only for obtaining food!
Around the same time, paleomastodons lived and died out. They were distinguished by obvious elephantine features: the structure of the body, skull, and the presence of tusks, which were no longer involved in chewing. On the lower jaw they were spade-shaped; scientists suspect that animals used them to obtain food in the upper layer of the earth.
6 Deinotherium (17 million years ago)
Strictly speaking, scientists are not sure whether Deinotherium was the ancestor of the elephant. It may well be that this is just a separate branch of evolution that has not survived to this day (but early people saw it, because Deinotherium disappeared 2 million years ago). Well, they were terrible animals: with tusks curved down, a huge trunk, a massive (up to 1.2 m) skull, up to 4.5 meters high!
7 Platybelodon (15 million years ago)
Another representative of the proboscis on the way to modernity acquired formidable tusks protruding forward and a powerful lower jaw with spade teeth. Platybelodons lived, as they now say, everywhere: in America, Eurasia and Africa.
8 Gomphotherium (3.6 million years ago)
Add sharp tusks on the lower jaw to the modern Indian cutie elephant, straighten those on the upper jaw, and you get a gomphotherium. And he won't look so friendly anymore. The tusks of gomphotheriums differed from modern elephants in that they had real tooth enamel!
9 Stegodons (2.6 million years ago)
Height 4 meters, length 8 meters + 3 meters of tusks make these extinct proboscis one of the largest ancestors of elephants. The last specimens were preserved on the island of Flores until 12 thousand years ago in a dwarf form, where hobbits (Homo Florentine) were discovered. The species is so close to modern ones that the elephants of Bardia Park still show features of Stegodons.
10 Primelphas (2.6 million years ago)
And now, finally, we come to the closest relative of elephants - in fact, this is its ancestor, primelfas, or “the first elephant.” It was he who gave rise to the branches of elephants, mammoths and mastodons. Meanwhile, it didn’t look much like a modern elephant, since it had four tusks, but what can you do, it’s still related.
Among the land animals of the Earth, one creature stands out in every way - size, impressive body, huge ears and a strange nose, very similar to the sleeve of a fire hydrant. If among the zoo's living creatures there is at least one creature of the elephant family (and we are talking about them, as you already guessed), then this enclosure is especially popular with visitors, young and old. I decided to understand the genealogy of elephants, calculate their most distant ancestor, and, in general, understand “who is who” among the long-eared and trunk-equipped. And this is what happened to me...
It turns out that elephants, mastodons and mammoths, as well as pinnipeds dugongs and manatees, had a common ancestor - moeritherium (lat. Moeritherium). Externally, the moriteriums that inhabited the Earth approximately 55 million years ago were not even close to their modern descendants - short, no higher than 60 cm at the withers, they lived in shallow water bodies of Asia of the late Eocene and were something between a pygmy hippopotamus and a pig, with a narrow and elongated muzzle.
Now about the direct ancestor of elephants, mastodons and mammoths. Their common ancestor was the paleomastodon (lat. Palaeomastodontidae), which inhabited Africa about 36 million years ago, in the Eocene. The paleomastodon had a double set of tusks in its mouth, but they were short - it probably ate tubers and roots.
No less interesting, in my opinion, a relative of modern long-eared and proboscideans was a funny animal, nicknamed by scientists Platibelodon danovi. This creature inhabited Asia in the Miocene, about 20 million years ago, and had one set of tusks and strange spade-shaped incisors on its lower jaw. Platybelodon actually did not have a trunk, but its upper lip was wide and “corrugated” - somewhat similar to the trunk of modern elephants.
It's time to deal with more or less widely known representatives of the proboscis family - mastodons, mammoths and elephants. First of all, they are distant relatives, i.e. The two modern species of elephants - African and Indian - did not descend from mammoths or mastodons. The body of mastodons (lat. Mammutidae) was covered with thick and short hair, they ate mostly grass and foliage of shrubs, and spread to Africa during the Oligocene period - about 35 million years ago.
Contrary to feature films, where the mastodon is usually depicted as an aggressive giant elephant with huge tusks, they were not larger than the modern African elephant: their height at the withers was no more than 3 meters; There were two sets of tusks - a pair of long ones on the upper jaw and short ones, practically not protruding from the mouth, on the lower jaw. Subsequently, mastodons completely got rid of a pair of lower tusks, leaving only the upper ones. Mastodons became completely extinct not so long ago, if you look from an anthropological point of view - only 10,000 years ago, i.e. our distant ancestors were well acquainted with this species of proboscis.
Mammoths (lat. Mammuthus) - those same shaggy, proboscis and with giant tusks, the remains of which are often found in Yakutia - inhabited the Earth on several continents at once, and their large family lived happily for as long as 5 million years, disappearing about 12-10,000 years ago . They were much larger than modern elephants - 5 meters tall at the withers, huge, 5-meter tusks, slightly twisted in a spiral. Mammoths lived everywhere - in South and North America, in Europe and Asia, they easily endured ice ages and protected themselves from predators, but could not cope with the bipedal ancestors of humans, who diligently reduced their population throughout the globe. Although scientists still consider the main reason for their complete and widespread extinction to be the last ice age, caused by the fall of a huge meteorite in South America.
Today, two species of elephants exist and are relatively healthy - African and Indian. African elephants (lat. Loxodonta africana) with a maximum weight of 7.5 tons and a height of 4 meters at the withers, live south of the African Sahara Desert. Just one representative of this family is in the first image of this article.
Indian elephants (lat. Elephas maximus) with a weight of 5 tons and a height of 3 meters at the withers, are common in India, Pakistan, Burma, Thailand, Cambodia, Nepal, Laos and Sumatra. Indian elephants have much shorter tusks than their African relatives, with females having no tusks at all.
Elephant skull (varnished, sort of)
By the way, it was the skulls of mammoths, regularly discovered by ancient Greek researchers, that formed the basis of the legends about giant Cyclops - most often there were no tusks on these skulls (nimble Africans stole them for construction purposes), and the skull itself was very similar to the remains of a colossal Cyclops. Note the hole in the frontal part of the skull, to which the trunk is connected in living elephants.
Modern species of elephants are only the remnants of the great family of proboscis, which in the distant past inhabited planet Earth...