2015 brought hope for the revival of disappeared monsters
At the end of the year, it is customary to take stock, remember important events and make plans for the future. Of course, paleontologists are accustomed to looking into the past much further than a year, but what we saw in the outgoing 2015 is enough to say: paleontology is rapidly developing, opening new horizons in front of itself and penetrating deeper and deeper as into the depths of the earth. and in the essence of evolutionary perturbations.
Project of the Year: Recreation of Mammoths
The idea of returning the mammoth from oblivion did not appear in 2015, but it was in the last 12 months that it moved from the category of fruitless theorizing to the category of promising scientific research. After analyzing mammoth tissues preserved in the permafrost, scientists not only declared their readiness to clone them, but also named very specific dates - seven years.
Skeptics, of course, will immediately recall all the speculation and outright fraud that has accumulated around the resurrection of mammoths and cloning as such in recent years. But now it is not a dubious-looking researcher from a semi-normal Asian university that promises to bring back to life the furry northern elephants, but rather a respectable Harvard professor, author of a unique and widely used method of genetic engineering, George Church.
In his laboratory, Church modified the Crispr / Cas9 mechanism, which protects bacteria from viral attacks, and now with its help he has the ability not only to rewrite defective DNA, replacing damaged genes with healthy ones, but also to insert the right genes in the right places - the way people do it with words in a text editor.
The basis for the return of the mammoth, Church chose the genome of the modern Asian elephant, which, according to the scientist, is such a close relative to mammoths that it could well produce viable offspring from them. With the help of Crispr, Church is going to insert genes responsible for shaggy warm hair and the production of subcutaneous fat in the right places in elephant DNA, thus creating an elephant-mammoth hybrid.
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Image: Scherl / Global Look
Then, herds of genetically modified mammoth elephants will go to the taiga and tundra of Siberia and Canada to return to the tundra-steppe landscape that disappeared thousands of years ago, which protects the permafrost and protects the Earth from climate change.
On the Lyakhovsky Islands in the Arctic Ocean, mammoth tissue was found, potentially suitable for cloning. And although these materials were collected for the Russian-Korean project "Mammoth Revival", Church may be able to get some for his laboratory.
Victory of the Year: Kurosaurus is Coming
While some paleontologists are trying to resurrect the mammoth, others are busy inventing the dinosaur. More precisely, the kurosaurus, since the genetic material of the chicken became the starting material for it. As science enthusiasts believe, it is trivial layers that are genetically closest to the cruel ancient killers - theropods. Since the millions of years that have passed since their extinction, no DNA will survive, scientists had to resort to reverse evolution (or devolution), step by step canceling the evolutionary advances that led to the emergence of modern birds.
The pioneer of this project was Jack Horner, the author of the term "chikenosaur" and the prototype of Dr. Alan Grant from the movie "Jurassic Park". In 2014, he promised that the world would see a living dinosaur in five years. And his followers Arhat Abzhanov from Harvard and Bhart-Anjan Bhullar from Chicago in the spring of 2015 were able to grow chicken embryos with a reptile face instead of the usual bird's beak!
American biologists have created chicken embryos with dinosaur faces
Image: Bhart-Anjan Bhullar
This turned out to be difficult to achieve: the researchers had to selectively block the activity of two proteins responsible for the formation of the beak. As a result, the development of the head of the chicken embryo followed the dinosaur model and led to the formation of a wide, rounded muzzle. True, she is still covered with a horny sheath and is devoid of teeth, but the trouble is the beginning.
Chilean experts are approaching the reconstruction of dinosaurs from a completely different side. In a daring experiment back in 2014, they managed to get chickens to walk exactly like dinosaurs. To do this, Bruno Grossi and his colleagues attached heavy faux tails to the chickens. Immediately thereafter, the positioning of the paws and even the gait of the birds underwent noticeable changes, approaching those that should have been demonstrated by bipedal dinosaurs.
Modified tail chicken
Image: Grossi et al. 2014
Today it is still hard to believe, but it looks like in a few years or maybe decades, people will be able to witness battles between mammoths and dinosaurs in reality. It must be an amazing sight.
Person of the Year: Homo naledi
The past year has brought several new hominid species, but the most important finding has been the description of an early member of our own genus, Homo naledi. Outwardly, he was, of course, a crummy - one and a half meters tall, half a centner in weight and a brain the size of an orange. But appearances are known to be deceiving.
The most shocking thing in the life of this "transitional link" between normal modern man and prehistoric Australopithecus was the custom of burying their dead. This means that some rudiments of culture and even religion existed in Homo naledi. They did not just store the bodies of departed relatives, but placed them in an inaccessible cave, which protected them from destruction by scavengers.
So far, the remains of 15 individuals have been removed from the burial chamber of a folk who lived hundreds of thousands, if not millions of years ago. All bones are quite similar to each other, which gave reason to consider them the remains of not just individuals of the same species, but close relatives. But this cave has not yet revealed all of its secrets, says South African anthropologist Lee Berger. It is possible that even more interesting evidence of prehistoric civilization awaits its researchers.
Remains of Homo naledi
Photo: Themba Hadebe / AP
However, there are still more questions around Homo naledi than answers. For example, the passage leading to the burial chamber is 17.8 cm wide. It is not clear how the ancient people squeezed in there and how did their remains end up there? Versions about transportation by streams of water, predators and rodents do not stand up to criticism. The age of the fossils is also completely unclear. For some reason, South African scientists did not carry out radiocarbon analysis, and without it, it is impossible to date bones with any accuracy.
These inconsistencies were immediately taken advantage of by the critics of Berger, who vied with each other to doubt that this was really a new species, and not some of the human ancestors already known to science; they assured that funeral practices are not peculiar to primitive people - in a word, they attacked the scientist's work from literally all sides. But Berger is unshakable because the bones of Homo naledi are the most representative series of human fossils ever found in Africa.
Monster of the Year: Aegirocassis benmoulae
Choosing the main monster of 2015 proved to be a daunting task. Throughout the year, paleontologists tirelessly expanded the lists of long-extinct creatures, discovering several new species a week. There were predatory raptors, and powerful ceratopsians, and feathered, but not birds - amazing flying lizards. The most striking of all were the mysterious inhabitants of the Early Paleozoic seas, of which neither direct descendants nor even close analogues remained. We are talking about primitive arthropods - aegirocassis.
In their time, any organism that a person could see without a magnifying glass was considered large. The length of half a meter is a serious claim for the title of giant, and only a few species of cephalopods were even larger. Aegirocassis, somewhat reminiscent of a monstrous shrimp, grew up to two meters in length, and ate about like modern whales, straining a variety of living trifles from the water. But if a whale-shaped filter built into the mouth serves for this purpose for whales, the aegirocassis have grown a bulky chandelier-like structure from their own jaws on the outer contour of their body.
Aegirocassis benmoulae
Image: Spiridon Ion Cepleanu / Wikipedia
The discoverer of Aegirocassis benmoulae, Peter Van Roy, at first did not even understand what he was dealing with - so dirty and shapeless was the sample delivered to the laboratory of Yale University from Morocco. But as the preparators removed the waste rock, a three-dimensional fossil of a huge sea creature appeared before the researchers' eyes. Paleontologists were particularly struck by four rows of swimming limbs - two lower and two upper.
The "legs" of the aegirocassis did not at all resemble lobster claws or the long articulated stilts of crabs. They are most likely modified into fins. Yale paleontologists believe that both Aegirocassis and their relatives were great swimmers. True, if the predatory relatives of the Ordovician "whales" quickly swim and maneuver rapidly in the water column in order not to be left without lunch, then why the unique mobility was needed by a giant but completely peaceful plankton-feeding filter feeder is still unclear.
Triumph of the Year: Tyrannosaurus Rex's Blood Vessels Opened
The year round of paleontological news will end with a real Christmas story. It shows in the best way possible that the process of scientific knowledge of the world cannot be stopped, even if representatives of science itself try to do it. As it should be in a Christmas story, everything ends well.
In 2005, North Carolina State University paleontologist Mary Schweitzer reported that she was able to find remnants of soft tissue in the bones of a Tyrannosaurus. A couple of years later, Dr. Schweitzer confirmed this sensational statement in all respects with the publication of a scientific article on the successful isolation of collagen from the fossil femur of Tyrannosaurus rex, a protein that plays an important role in the formation of animal connective tissues.
But instead of the expected honor (and maybe the Nobel Prize), almost the entire scientific world fell on the woman scientist. She was accused of falsification, reproached for obscurantism and clericalism, she even remembered her work as a veterinarian … And all because from the point of view of science at the beginning of the 21st century proteins and cells of ancient animals could not survive for millions of years. Having literally trampled on Schweitzer's works and declared the organics she found to be bacterial biofilms of modern origin, the scientific world calmed down.
Tyrannosaurus rex blood vessels
Image: creationstudies.org
Fortunately, Mary Schweitzer turned out to be a tough nut to crack. She not only continued her research, but practically founded her own scientific school. And in 2015, a colleague of Schweitzer at the university, Tim Cleland, isolated from the thigh bone of a duck-billed dinosaur, which died out 80 million years ago, not proteins, but whole blood vessels, which included at least two laboratory proteins - collagen and myosin … And in the lumens of the vessels, red blood cells are visible 80 million years old!
Cleland's technique is flawless: samples taken from Cretaceous bones have been tested for antibodies and peptide sequence analysis. And both lines of evidence have convincingly demonstrated that it is not fungi or bacteria that are in the test tubes, but the tissues of the real archosaurs. The critics of these works have no arguments that deserve attention, which means that today humanity is holding in its hands the genuine soft tissues of dinosaurs - a scientific event unimaginable even ten years ago.
“This study is the first direct blood vessel analysis of an extinct organism. It gives us the opportunity to understand what types of proteins and tissues can be preserved and how they change during fossilization, says Cleland. "It also provides new opportunities for addressing the evolutionary relationships of extinct organisms, and can identify protein modifications and the timing of their appearance in different evolutionary lines."
So, quite in the spirit of Christmastide stories, this story ended. And the progressive scientific community can only express gratitude to Dr. Schweitzer, admire the firmness of her character and wish everyone a Happy New Year and Christmas.
Dmitry Samarin
