Genetic engineering is one of the most revolutionary sciences. Scientists are still discussing its possible ban. And while they are arguing, the cloning process is successfully underway in scientific laboratories. Everyone is interested in knowing how things are going with dinosaur cloning.
There is a dubious theory according to which the DNA of a dinosaur can be isolated from the blood of a female mosquito that bit it. This insect is supposedly preserved in amber. This dinosaur clone successfully appeared in the film Jurassic Park.
Of course, it is unlikely to find such a mosquito that bit a pangolin a second ago and immediately fell into a drop of pine resin. It is also highly doubtful that dinosaur DNA in its pure form could be preserved in amber. The hypothesis itself leads to only one conclusion - DNA must be searched for or somehow recreated, but how exactly is still difficult to say.
Almost all Scientific minds are very skeptical about the possibility of finding dinosaur DNA. They give the following reasons: 1. Over the course of 500,000 years, any DNA structure can collapse if it is not exposed to low temperatures. 2.no one has yet managed to find whole DNA; these are always short pieces of a chain that cannot be connected. 3. The most difficult thing is to sift out the pieces of genetic material we need from foreign DNA that was introduced by chance later or simply belongs to bacteria from the era of life of a given dinosaur.
But when a person has a dream, then “the fairy tale becomes reality.” And the impossible becomes possible.
2010 can be called a breakthrough year in the history of DNA reconstruction. 50-75 thousand years ago, extinct ancient people, the Denisovans, lived on Earth together with the Neanderthals. Paleontologists managed to find the remains of a Denisovan girl. Experts were able to decipher the child’s genetic code, since know-how had been developed before this
— reconstruction of fragments of a DNA molecule consisting of a single chain. This discovery became the basis for further clues to evolutionary development on Earth.
year 2013. another breakthrough! The remains of an ancient horse were found in permafrost. They are 550 - 780 thousand years old. Scientists manage to read this genome.
Then another sensation - specialists manage to decipher mitochondrial DNA Heidelberg man. This type of Neanderthal lived approximately 400 thousand years ago. In parallel with this, work is being successfully carried out on the genetic structure of the remains of a bear that lived at the same time. The most surprising thing is that the remains of both man and bear were found not in permafrost, but in a warmer climate. What does this mean? It is possible to clone ancient animals not only from frozen remains, but to expand the area of searching for DNA fragments using a new technique.
This technique, like all ingenious things, is simple. To purify the desired DNA from the presence of foreign DNA, Scientists created a so-called DNA template: gene sequences of 45 nucleotides were taken (longer chains are unlikely to be preserved) with existing mutations that occurred after the death of an individual (certain nucleotide substitutions appear after the death of a cell). Then, after analyzing this piece of genetic material, they found the closest DNA, which made it possible to build the correct chain of genes. This is reminiscent of working on puzzles - the overall picture is there, you just need to put it together correctly in small pieces. The Denisovan genome was best suited for this purpose.
This method only works when there is the following base:
1.successful template for genome reconstruction
2. a sufficient number of DNA chain fragments.
We gain new knowledge and a new template with each new transcript. And we delve into the study of more accurate historical events. But so far all these discoveries are limited by a period of no more than 800,000 years. So what about the dinosaurs that lived on Earth from 225 to 65 million years ago? Over such a long period of time, not a single intact DNA molecule would have been preserved, but even here science does not stop at one place.
In the Chernyshevsky region, scientists discovered fragments of fossilized skin of a dinosaur that lived in the Jurassic Period. Scientists have raised the question of real cloning of dinosaurs. Dozens of news agencies showed interest in Transbaikalia in connection with this discovery. Foreign and Russian Scientists came to the institute and admitted that they had never seen anything like this in their lives.
Cloning, of course, has not yet been put on the conveyor belt, and experiments are still being conducted in private or departmental university laboratories. Russian researchers are now hard at work cloning a mammoth. The mammoth genetic material itself is not very difficult to obtain. Let us remember the baby mammoth Dima, who was found whole. Actually, mammoths lived only a few thousand years ago, so their frozen remains have been found more than once in Siberia. There is evidence that back in the 19th century, Siberian hunters fed their dogs mammoth meat. Of course, making a clone of a mammoth from an entire preserved chain of DNA and good quality protein is not very difficult for specialists.
It's much more difficult to clone a dinosaur. According to Doctor of Geological and Mineralogical Sciences Sofia Sinitsa, the period of DNA decay depends on the conditions under which the remains are found and is 500 thousand years. And we must take into account that dinosaurs went extinct approximately 65 million years ago. But many of them lived 150 million years BC. WELL, HOW DO YOU FIND DINOSAUR DNA? The shelf life of DNA baffles researchers. After all, organic tissue is transformed into minerals over millions of years. In rocks that can be analyzed, it actually does not exist. Sofya Sinitsa places a special emphasis on the fact that nothing works with dinosaur skin, in which organic matter could be preserved, and therefore cloning of dinosaurs will have to be done only after geneticists have successfully cloned a mammoth. The scientist promises that in order to find the source material for cloning lizards, she will “dig up all of Siberia.”
Do you remember very well from school curriculum that DNA plays the function of transmitting hereditary information. If one of the researchers can find one single completely preserved cell with a complete set of DNA molecules, then further cloning exact copy It's just a matter of technique. For example, take the egg of a modern Komodo dragon, destroy the original DNA, and add DNA molecules from any species of dinosaur into the egg. Now you can put the egg in a special incubator and wait for the birth of the little dinosaur.
Julie Feinstein of the American Museum of Natural History retrieves a frozen tissue sample from an endangered animal.
Is it really necessary to resurrect dinosaurs from flesh and blood if computer technology will soon make them completely “alive”?
The stuffed sheep Dolly is preserved in the museum today
“Solve all your problems with simple freezing” - Applied Cryogenics slogan from the animated series “Futurama”
Science fiction writers and futurologists have more than once predicted that in the future extinct creatures will be “restored” again through cloning using preserved—say, frozen—DNA fragments. To what extent this is even possible is not yet entirely clear. However, a large-scale project has already been launched in the United States to preserve frozen tissue samples of rare and endangered animals.
In principle, such cloning has already taken place - Spanish scientists “revived” the Iberian goat, the last representative of which died in 2000. However, the cloned animal did not last even 7 minutes, dying from a pulmonary infection. However, many experts considered this a major success, which inspired the emergence of new collections of frozen specimens, including the project of the American Museum of Natural History (AMNH). And who knows whether such repositories will serve as truly invaluable " Noah's Ark", capable of saving many species from complete extinction.
The AMNH repository has space for approximately 1 million samples, although it is still a long way from reaching that number. Butterflies, frog legs, a fragment of whale skin and crocodile skin - such samples are preserved in containers cooled with liquid nitrogen. And according to a recently concluded agreement with the American National Park Service, the collection will be replenished with new exhibits. For example, already in August, scientists are preparing to accept blood samples from the island fox, which is on the verge of extinction. In theory, such frozen cells could one day be used for cloning and the complete “resurrection” of an extinct species. But so far no scientific group has been able to do this.
For example, the Spaniards, who cloned the Iberian goat, almost literally followed the method of the British Ian Wilmut - the same one who literally shocked the whole world in 1997 by introducing the cloned sheep Dolly. This showed the fundamental possibility of cloning mammals - moreover, the sheep lived for more than 6 years and died in 2003. However, both Dolly and the Spanish goat were cloned with nuclear transfer: scientists took the egg of one animal and removed the nucleus from it, and instead introduced a nucleus from cells from the animal you wanted to clone. This “hybrid” cell was then placed into the surrogate mother’s body.
This method requires the ideal state of the animal cell that scientists intend to clone. This might still work for sheep and goats, but what about the many extinct or endangered species that have no horns or legs left? Even in cryogenic storage, DNA slowly degrades over the years, and samples preserved under “natural” conditions contain only a small part of their genome.
However, modern computer technologies make it possible to meticulously reconstruct the complete genome of an extinct species by combining data from several samples. In this way, work is being done to genetically map ancient mammoths and even Neanderthals. Quite significant fragments of the genome of other extinct species have already been obtained - for example, the cave bear or the moa, a giant bird that reigned in New Zealand before the Maori aborigines arrived here.
And German researchers managed to work well with the Neanderthal genome - however, only its mitochondria (special organelles, “power stations” of our cells, which have their own genetic material). And if the moa birds became extinct about a thousand years ago, then Neanderthals have not existed for about 40 thousand years - and the work of scientists from Germany is all the more valuable. However, all these approaches will never work with samples older than 100 thousand years: during this period the DNA completely degrades.
So, will we never see a “dinosaur park” in whose enclosures real cloned tyrannosaurs or giant diplodocus live? Who knows. For example, not long ago, a method of “reverse evolution” was proposed to restore the genome, which consists of working with the genotype of “living relatives” of an extinct species.
Californian scientist Benedict Paten and his colleagues are working on this approach. Their solution is to sequence the genomes of many individual members of related species, and then compare them so that, using special algorithms, they determine the “source code”. For example, by “calculating” the genomes of humans and chimpanzees, the authors were able to “arrive” at four of our common ancestors, which they reported in a publication last fall.
However, this method, of course, is not ideal and has its limitations. The revival of the dinosaurs is delayed again. And even if we manage to obtain data on the genomes of all living organisms on the planet, some of the extinct species simply did not leave any descendants. They have disappeared, and it is unlikely that information about their DNA can somehow be obtained.
But let’s say we managed to obtain a complete transcript of the genome of some extinct species. This is only part of the task, because we still need to get a living organism. And this is an almost divine task: to move from information encoded in DNA to a real being.
First, you will need to synthesize the DNA itself and somehow correctly divide its strands into the necessary chromosomes and fold them - also in exactly the unique way in which they were folded and ordered in a once living creature. Even at this stage today the task is insoluble. But let’s say we managed to do this, say, using a biologist robot who made hundreds of thousands of attempts and found the only correct option (we wrote about such robots in the article “The Beginning of a New Era”). You will need an "eviscerated" egg into which you can place the chromosomes into the nucleus before implanting it into the surrogate mother. And everything we know about the nature and nature of genetic diseases allows us to add: the slightest mistake will lead to complete collapse. In a word, all this looks too complicated and is unlikely to allow cloning even a mammoth in the foreseeable future. Perhaps it would be easier to invent a time machine.
Although the famous American geneticist George Church offers a completely original approach. It is not necessary, he believes, to clone a whole ancient animal. In the same mammoth, we are interested in a hairy elephant, so it is easier to take an ordinary elephant and turn off the genes that determine its lack of hair, and instead introduce into it those that are responsible for the hair of a mammoth. Step by step, we can add other characteristic elements of a mammoth to the elephant - say, change the shape of the tusks and so on - until we are more or less closer to the “original source”. The method is also more than controversial - after all, we, in fact, are not restoring extinct species, but creating new ones.
And is all this necessary? Many scientists are inclined to believe that the enormous challenges involved in “revitalizing” once-extinct species are not worth it. Imagine that we restore the same moa birds - their impact on the ecosystem of modern New Zealand will most likely be deeply destructive. And spending enormous amounts of effort and money just to get a few birds for a zoo seems like the height of wastefulness. It is difficult to talk about the ethical issues of cloning, say, Neanderthals. As some experts wisely note, rather than restoring what was lost, it is better to preserve what is still available. And we cannot disagree with them.
Probably every reader has seen the film by the famous director S. Spielberg about an island where cloned giant lizards roam in an amusement park. At one time, after watching the film, many wondered: is a dinosaur clone a myth or reality?
The most interesting thing is that this question interested not only idle onlookers. Genetic scientists, funded by very wealthy people, have taken up the problem of cloning in earnest.
Dinosaur DNA is gone
Australian billionaire Clive Palmer, who became famous for creating a copy of the infamous Titanic, was inspired by the idea of creating his own park with giant lizards. To do this, you just need to get a clone of these prehistoric creatures, but is such a task possible for a person, even if he has a tightly stuffed wallet (sorry, suitcase) of money? Unfortunately, no, the scientists answered.
For a long time, Australian researchers have been working on the problem of preserving DNA in the bones of ancient birds and the likelihood of obtaining it. The tests were carried out on the bones of ancient birds called moas.
These giants once inhabited New Zealand, but five hundred years ago they were practically destroyed by the local population. Genetic scientists studied bones whose age reached 8 thousand years or more. It turned out that DNA molecules disintegrated quite quickly in the bones. After one and a half million years, the genetic material cannot be used for reading, and after seven million years it completely disintegrates. And even ancient insects encased in amber do not possess any DNA.
The most famous dinosaurs
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Tyrannosaurus(aka Tyrannosaurus Rex). This is an unsurpassed predator, a real killing machine. Old Rex is familiar to anyone who has watched Jurassic Park. It is believed that, given its enormous dimensions, the lizard was capable of reaching speeds of up to 60 km/h. |
Diplodocus. This peaceful herbivorous lizard had an impressive size - its body length reached 40 meters! Diplodocus spent most of its life in water, and they came to land to eat or lay eggs. |
Triceratops. Characteristic feature This massive dinosaur features three horns and an openwork “collar” around its neck. The appearance of Triceratops bore some resemblance to the modern rhinoceros. This dinosaur weighed about 12 tons and was a herbivore. |
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Pterodactyl. Representative of Jurassic aviation. What can you say about this lizard? It had a rather large beak with teeth, and the wingspan of the “bird” reached 12 meters. Pterodactyl could snatch fish out of the water on the fly, thanks to its dexterous paws with “fingers.” |
Allosaurus. Another terrible predator that attacks its prey in a jump. The jaw of the Allosaurus had approximately 70 teeth, ranging from 10 to 15 cm in length. The long and muscular tail helped the predator maintain balance when walking and running. |
Plesiosaur. This is an aquatic lizard with incredible long neck. Some believe that the famous monster of Loch Ness may be a descendant of a plesiosaur. The main diet of this lizard was fish. The plesiosaur had large flippers, which allowed it to maneuver in the aquatic environment. |
Chicken ancestors could bite painfully
No one even doubts that Scientific research in the field of paleontology will continue, but the conclusion has already been made. He tells us that it is impossible to create an amusement park with giant lizards. But don't be upset! Extinct giants can be revived in another way.
How often do we eat chicken? But we don’t even think for a minute that this is the meat of a descendant of a prehistoric lizard. It's funny that our chicken and the ancient monster have similar DNA, and the chicken embryo is equipped with a large scaly tail and saber-toothed jaws. What is the task facing genetic scientists at the present time? They had the opportunity to study the genetic information of a bird to obtain a dinosaur.
Relatively recently, American researchers came to the conclusion that the composition of ostrich blood is very similar to the composition of the blood of giant lizards. And this discovery gives hope for obtaining the DNA of these extinct individuals. In all likelihood, a lot of interesting things await us. And maybe we will be able to see a real “dinosaur park” with our own eyes.
03/09/2016 at 01:28
The idea of cloning dinosaurs from fossil remains was especially relevant after the release of the film “Jurassic Park,” which tells how a scientist learned to clone dinosaurs and created an entire amusement park on a desert island, where you could see a living ancient animal with your own eyes.
But a few years ago, Australian scientists under the leadership of Morten Allentoft and Michael Bunce from Murdoch University (Western Australia) proved that it is impossible to “Recreate” a living dinosaur.
Researchers radiocarbon dated bone tissue taken from the fossilized bones of 158 extinct moa birds. These unique and huge birds lived in New Zealand, but 600 years ago they were completely destroyed by the Maori aborigines. As a result, scientists found that the amount of DNA in bone tissue decreases over time - every 521 years, the number of molecules is reduced by half.
The last DNA molecules disappear from bone tissue after about 6.8 million years. At the same time, the last dinosaurs disappeared from the face of the earth at the end of the Cretaceous period, that is, about 65 million years ago - long before the critical threshold for DNA of 6.8 million years, and there were no DNA molecules left in the bone tissue of the remains that paleontologists were able to find.
“As a result, we found out that the amount of DNA in Bone Tissue, if kept at a Temperature of 13.1 degrees Celsius, decreases by half every 521 years,” said the head of the research team, Mike Bunce.
“We Extrapolated this Data to Other, Higher and Lower Temperatures and Found that If Bone Tissue is Maintained at a Temperature of Minus 5 Degrees, the Last DNA Molecules Will Disappear in Approximately 6.8 Million Years,” he added.
Sufficiently long fragments of the genome can only be found in frozen bones no more than a million years old.
By the way, to date, the most ancient DNA samples have been isolated from the remains of animals and plants found in permafrost. The age of the found remains is about 500 thousand years.
It is worth noting that scientists will conduct further research in this area, since differences in the age of the remains are responsible for only 38.6% of the discrepancies in the degree of DNA destruction. The rate of DNA decay is influenced by many factors, including the conditions of storage of remains after excavations, chemical composition soil and even the time of year in which the animal died.
That is, there is a chance that in conditions eternal ice or underground caves, the half-life of genetic material will be longer than geneticists assume.
How about a mammoth?
Reports that scientists have found remains suitable for cloning appear regularly. Several years ago, scientists from the Yakut Northeastern Federal University and the Seoul Center for Stem Cell Research signed an agreement on working together over cloning a mammoth. Scientists planned to revive the ancient animal using biological material found in permafrost.
A modern Indian elephant was chosen for the experiment, since its genetic code is as similar as possible to the DNA of mammoths. Scientists predicted that the results of the experiment would be known no earlier than in 10-20 years.
This year, messages from scientists from the North-Eastern Federal University appeared again; they reported the discovery of a mammoth that lived in Yakutia 43 thousand years ago. The collected genetic material suggests that intact DNA has been preserved, but experts are skeptical - after all, cloning requires very long DNA chains.
Living clones.
The topic of human cloning is developing not so much in a scientific manner as in a social and ethical one, causing controversy on the topic of biological safety, self-identification of the “New Man”, the possibility of the emergence of defective people, and also giving rise to religious controversy. At the same time, animal cloning experiments are being carried out and have examples of successful completion.
The world's first clone, the tadpole, was created back in 1952. Soviet researchers were among the first to successfully clone a mammal (house mouse) back in 1987.
The most striking milestone in the history of cloning living beings was the birth of Dolly the sheep - this is the first cloned mammal obtained by transplanting the nucleus of a somatic cell into the cytoplasm of an egg devoid of its own nucleus. Dolly the sheep was a genetic copy of the cell donor sheep (that is, a genetic clone.
Only if, under natural conditions, each organism combines the genetic characteristics of its father and mother, then Dolly had only one genetic “Parent” - the prototype sheep. The experiment was carried out by Ian Wilmut and Keith Campbell at the Rosslyn Institute in Scotland in 1996 and was a breakthrough in technology.
Later, British and other scientists conducted experiments on cloning various mammals, including horses, bulls, cats and dogs.
Once upon a time, giant, majestic monsters roamed our planet - dinosaurs. They swam, flew, ate each other and plants, multiplied, evolved. We felt “at ease”. Until problems with volcanoes appeared, which smoothly turned into the fall of a powerful asteroid. Thus came the end of the dinosaurs. We know they existed because we find their remains buried millions of years underground. But what if you took the DNA of a dinosaur, pulled it out of the dust and tried to recreate the great lizard?
When paleontologists discovered a clutch of Jurassic dinosaur eggs in China in 2010, Steven Spielberg immediately protected the rights to his notorious film. But paleontologists rejoiced at a much less glamorous use for eggs: the ability to figure out how such large creatures grew from such small eggs.
Is it possible to resurrect dinosaurs and return them to this world? Paleontologist Jack Horner argues that we know very little about the issue of resuscitation. After studying the microscopic structures of several bones, Horner found that some dinosaurs, or rather their skeletons, developed similarly to some descendants of birds. And just as the cassowary doesn't grow its distinctive crest until late in life, some dinosaurs retained juvenile features well into adulthood. But paleontologists were wrong when they tried to analyze the bones: five key features from the Cretaceous period are believed to have belonged to juvenile versions of known dinosaurs. It seems that figuring out exactly how dinosaurs reproduced was much simpler.
After this, the question arose about the need for more information. In 2010, a breeding colony of lufengosaurus was discovered. It contained about 200 complete bones of long-necked dinosaurs, along with fragments of bones and eggshells - about 20 embryos at various stages of development. According to various estimates, the age of the find was 190-197 million years. These are the oldest dinosaur embryos ever found.
The find was enough to keep paleontologists and dinophiles excited for a couple of weeks, but there was more to it than that. In “marginal notes,” the scientists wrote that along with the bones they found “organic remains that are probably a direct product of the breakdown of complex proteins.” Hence the question: can we resurrect dinosaurs?
Now this question is no longer shocking, but the answer is still “no.” Despite the amazing leaps forward in genetics and genomic research, the practical problems of obtaining and cloning dinosaur DNA make Jurassic Park impossible even if society allowed it and the church agreed to the final test.
Dinosaur eggs
In the 1994 film Dumb and Dumber, Mary Swanson tells Lloyd that their chances of being together are about "one in a million," to which he replies "so you're saying there's a chance." Paleontologists probably feel the same way as Mary when they answer questions about dinosaur resuscitation. In addition, they are surprised that almost every one of the questioners watched “Jurassic Park” and did not understand the danger of the consequences.
Could the discovery of dinosaur eggs pave the way? new way reptiles on this planet? No. Dinosaur eggs lay for tens and hundreds of millions of years, their shelf life expired a long time ago, and they also became fossilized - this is not material for an incubator. Embryos are just a pile of bones. It won't help either.
Regarding organic material, can dinosaur DNA be extracted from it? Not really. Paleontologists constantly argue about the suitability of organic matter, but DNA has never been extracted (and, apparently, never will be able to).
Take, for example, the Tyrannosaurus rex (which is a rex). In 2005, scientists used weak acid to extract weak and pliable tissue from the remains, including bone cells, red blood cells and blood vessels. However, subsequent studies showed that the find was just an accident. People got really excited. Additional Analysis using radiocarbon dating and scanning electron microscopy showed that the material for the study was not dinosaur tissue, but bacterial biofilms - colonies of bacteria interconnected by polysaccharides, proteins and DNA. These two things look quite similar, but have more in common with dental plaque than with dinosaur cells.
In any case, these findings were very interesting. Perhaps the most interesting thing we haven't found yet. The scientists perfected their techniques and, when they got to the lufengosaurus nest, they braced themselves. Captivating? Absolutely. Organic? Yes. DNA? No.
But what if it's possible?
there is hope
Over the past ten years, advances in stem cells, ancient DNA resuscitation, and genome restoration have brought the concept of “reverse extinction” closer to reality. However, how close and what this might mean for the most ancient animals is still unclear.
Using frozen cells, scientists successfully cloned a Pyrenean ibex known as a bucardo in 2003, but it died within minutes. For years, Australian researchers have been trying to bring back to life a southern species of mouth-feeding frog, the last of which died decades ago, but their venture has so far been unsuccessful.
This is how, stumbling and cursing at every step, scientists give us hope for more ambitious resuscitations: mammoths, passenger pigeons and Yukon horses, which became extinct 70 thousand years ago. This age may be confusing at first, but just imagine: that's one-tenth of a percent of the time the last dinosaur died.
Even if dinosaur DNA were as old as yesterday's yogurt, numerous ethical and practical considerations would leave only the craziest of scientists among those who would support the idea of resurrecting dinosaurs. How are we going to regulate these processes? Who will do this? How will resurrecting dinosaurs affect the Endangered Species Act? What will failed attempts bring, besides pain and suffering? What if we resuscitate deadly diseases? What if invasive species grow on steroids?
Of course, there is growth potential. Like the representation of wolves in Yellowstone Park, a “rollback” of recently extinct species could restore balance to disturbed ecosystems. Some believe that humanity owes a debt to the animals it has destroyed.
The DNA problem, for now, is a purely academic issue. It is clear that resurrecting some frozen baby mammoth from a frozen cage may not arouse much suspicion, but what to do with dinosaurs? The discovery of a Lufengosaurus nest may be the closest we've ever gotten to Jurassic Park.
As an alternative, you can try to crossbreed an extinct animal with a living one. In 1945, some German breeders claimed that they were able to revive the aurochs, the long-extinct ancestor of modern cattle, but scientists still do not believe this event.
