American writer, screenwriter and producer Michael Crichton published his bestselling book Jurassic Park in 1990. Three years later, his compatriot filmmaker Steven Spielberg made a sci-fi thriller based on the novel, in which a handful of tourists escape from hordes of angry prehistoric reptiles cloned by scientists. The film is spectacular, breathtaking. However, the main merit of its authors is that they told the world about the amazing possibilities of genetic engineering.
Genetic Engineering
The history of genetics begins with the Austrian biologist and botanist Gregor Johann Mendel, the author of the famous laws that have become the cornerstone of the modern science of heredity. Today, the horizons of genetics are extremely wide - from the creation of new types of food to the cloning of living things. Such a section of it as genetic engineering allows you to take genes from the cell of one organism and place them in the cell of another.
The first successful experiment in this direction was made in 1972 in the laboratory of Stanford University (USA). Scientists have combined the DNA of two different viruses and one bacterium, creating a completely new organism. Nowadays, by extracting genes and proteins from any organism, researchers have learned not only to control its activity, but also to create new genotypes, types of living beings that are resistant to radiation, capable of dwelling under water, regenerating damaged organs and even … living forever.
Cloning is one of the biotechnologies of the future. At first, clones (from the Greek - "twig", "shoot") were called plants obtained from one producer in a vegetative way. But later this term acquired a broader meaning. In fact, cloning is either the replication of the same biological species, or the recreation of a particular living creature from its DNA. Scientists are conducting successful experiments to artificially produce identical molecules, cells and whole organisms. For example, in 1977, the first cloned animals appeared in Oxford - frogs, and in 1988 - rabbits.
Ian Wilmot and Keith Campbell, biologists at the Rosslyn Institute in Scotland, have experimented with cloning sheep since the end of the last century. First, they placed genetic material from the embryonic cell of a donor sheep into the germ cell of a living sheep. As a result, two healthy lambs were born - Megan and Morag. The researchers went further - and in 1996 they repeated the experiment, in which they used a previously frozen cage of the udder of a dead sheep. The famous Dolly the sheep was born, which became a sensation in the scientific world. Dolly lived happily for six and a half years and was put to sleep in 2003.
Resurrection candidates
With the birth of Dolly, wonderful prospects opened up for biologists. It became clear that any deceased creature could be cloned if there was genetic material left of it. A series of brilliant experiments followed. In 2008, a clone of a mouse was obtained using frozen cells at the Japanese Institute of Physical and Chemical Research. Interestingly, back in 2000, scientists figured out how to freeze a piece of tissue from the last wild Pyrenean goat. As if they knew that he could be resurrected. And after nine years it really happened. Unfortunately, the clone survived for only a few minutes and died due to respiratory failure. But now it became clear to everyone that such experiments can and should be carried out. There are many candidates for "resurrection" in the world. Although scientists understand that they are taking on a huge responsibility. Firstly, they have the right to clone,first of all, those species of animals that have disappeared through the fault of man. Secondly, you need to know for sure that the revived species will be able to adapt to modern living conditions - ecology and temperature on the planet. There is also an ethical aspect of the problem. If, say, a tyrannosaur is cloned, then it will have few competitors among the predators, which means that the fauna of entire regions will undergo significant changes.
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So who's on the list?
Dodos and smilodons.
The dodo bird is a good option. Dodo, or dodo, are large flightless birds that lived on the Mascarene Islands in the Indian Ocean. In addition, they did not swim well and ran slowly. But they had nothing to fear - there were no large predators on the islands. Until European sailors got there. The Portuguese and then the Dutch hunted dodos to replenish the ship's food supplies. In addition, they brought rats, cats and dogs to the islands, which ate the eggs of helpless birds. In general, the dodo had no chance of survival. True, now it is hardly possible to find in the hot climate of the islands the remains of a dodo with the necessary amount of DNA.
The next candidate for resurrection is the saber-toothed tiger, or smilodon, which became extinct about 10,000 years ago. These cats weighing up to 400 kilograms lived in South and North America. Not far from Los Angeles are the La Brea tar pits. So, in these pits, archaeologists have discovered thousands of remains of ancient animals of the Pleistocene period (2.5 million - 10 thousand years BC). Nine out of ten remains of mammals extracted from these pits belong to predators. The pits became a real trap for them. As soon as it got there, the animal began to roar, all the predators of the area came running to the noise and pounced on the victim. At the same time, they themselves were drowning in a viscous quagmire.
To date, scientists have removed the remains of two thousand smilodons from the pits. There is enough material for cloning. But there are problems. The first is that the resin could damage the DNA. The second is that smilodon in the modern animal world is no better than a tyrannosaurus.
But we are not talking about dinosaurs yet: DNA can be stored for thousands, but by no means millions of years.
Mammoths and neanderthals
Today, scientists have settled on the candidacy of the woolly mammoth. It is not a predator, it died out recently, just some ten thousand years ago. And on Wrangel Island, cut off from the mainland by the sea, the giants, in the absence of man, held out for a long time and became extinct about 4000 years ago. Their remains are perfectly preserved in permafrost conditions. In addition, scientists have long been able to decipher the genome of the woolly mammoth. At the same time, interesting details emerged. It turned out that the hemoglobin in the blood of mammoths, which is responsible for delivering oxygen to tissues, was adapted to cold temperatures, which is why climate warming could be the cause of the extinction of these animals. In the north-east of Yakutia, in the lower reaches of the Kolyma, there is a nature reserve called the Pleistocene Park. Under the leadership of the Russian ecologist Sergei Zimov, work is underway here to recreate the ecosystem of the Pleistocene tundra. The scientist believes that the Siberian tundra-steppes were once much more fertile, and their flora and fauna are much richer than they are now. But as a result, the saber-toothed tiger died out large - it degraded to its present state. The ancestor of modern man, a Neanderthal, had a hand in the disappearance of these animals.
The idea of the park is to relocate herbivores from their habitats to the Siberian tundra. Small herds of Yakut horses, reindeer, elk, musk ox, bison and maral are already grazing on the territory of the reserve. It is planned to bring here bactrian camels, yaks and saigas. And so that the herbivores do not relax, lions and Amur tigers will accompany them.
The woolly mammoth would become a real decoration of the reserve. There is even a museum of mammoth remains - pieces of skin, muscles and bones. This is a real treasure for a scientist. Zimin sent samples to Japan's Kinki University in Osaka, and in 2009, genetics Akira Iritani managed to put mammoth DNA into a mouse egg. The Japanese said that cloning a mammoth was a matter of several years. The same is stated by the Korean geneticist Hwang Wu Suk, who, in collaboration with Russian scientists, plans to clone the mammoth in the near future. And there it is a stone's throw to the resurrection of the first Neanderthal. True, it won't be easy. First of all, for ethical reasons - a person after all. In a number of states such as France. Germany and Japan, this is generally prohibited by law. However, in some countries the ban does not apply to the so-called therapeutic cloning,when a person is grown to the level of an embryo - to obtain stem cells.
Be that as it may, this issue is being actively discussed today, because humanity has approached a very dangerous line. Wouldn't be mistaken!
Magazine: Secrets of the 20th century №29. Author: Sergey Goncharenko