It's easy enough to forget that the ideas that seem obvious to us today were honed over the centuries by a group of smart people, and didn't just happen. The fact that we take them for granted is just the tip of the iceberg. interesting history. Let's dig deeper.

Realization that animals may disappear

If you walk along the beach and find an interesting fossil stone, you immediately understand that it may belong to a long-extinct species. The idea that species are dying out is so familiar to us that it's hard to even imagine a time when people thought that every single type of creature still lives anywhere. People believed that God created everything - why would he create something that could not survive?

George Cuvier was the first person to ask this question. In 1796 he wrote an article on elephants in which he described African and Asian varieties. He also mentioned a third type of elephant known to science only from its bones. Cuvier noted key differences in the third elephant's jaw shape and suggested that the species must be entirely separate. The scientist called it a mastodon, but then where are the living individuals?

According to Cuvier, "all these facts are consistent with each other and do not contradict any other message, so it seems to me possible to prove the existence of a world that preceded ours and was destroyed due to a kind of catastrophe." He did not stop at this revolutionary idea alone. Cuvier studied the fossils of other ancient animals - coining the term "pterodactyl" along the way - and found that reptiles were once the dominant species.

First cells grown outside the body

If a biologist wants to do research inner work animal cells are much easier if those cells are not part of the animal at the time. Currently, biologists are cultivating wide strips of cells in a test tube, which greatly simplifies the task. The first person to try to keep cells alive outside the host body was Wilhelm Roux, a German zoologist. In 1885, he placed part of a chicken embryo in saline and kept it alive for several days.

For several decades, research continued using this particular method, but in 1907 someone suddenly decided to grow new cells in solution. Ross Harrison took tissues from a frog embryo and was able to grow new nerve fibers from them, which he then kept alive for a month. Today, cell samples can be kept alive almost indefinitely - scientists are still experimenting with cell tissues from a woman who died 50 years ago.

Discovery of homeostasis

You have probably heard something about homeostasis, but in general it is very easy to forget how important it is. Homeostasis is one of the four essential principles of modern biology, along with evolution, genetics and cell theory. The main idea fits into a short phrase: organisms regulate their internal environment. But as with other important concepts that can be squeezed into a short and succinct phrase - objects with mass are attracted to each other, the Earth revolves around the Sun, there is no catch - this is a really important understanding of the nature of our world.

The idea of ​​homeostasis was first put forward by Claude Bernard, a prolific mid-19th century scientist who was kept awake by the fame of Louis Pasteur (although they were friends). Bernard made serious progress in understanding physiology, despite the fact that his love of vivisection destroyed his first marriage - his wife rebelled. But the true importance of homeostasis - which he called milleu interieur - was recognized decades after Bernard's death.

In a lecture in 1887, Bernard explained his theory thus: “A living body, though in need of environment, relatively independent of it. This independence from the external environment stems from the fact that in a living being, the tissues are essentially separated from direct external influences and protected by a true internal environment, which consists, in particular, of the fluids circulating in the body.

Scholars who are ahead of their time often go unrecognized, but Bernard's other work was enough to bolster his reputation. Nevertheless, it took nearly 50 years for science to test, validate, and evaluate his most important idea. An entry about it in the Encyclopedia Britannica for 1911 says nothing at all about homeostasis. Six years later, the same article on Bernard calls homeostasis "the most important achievement of the era."

First isolation of the enzyme

Enzymes are usually first learned in school, but if you've been skipping classes, let's explain: they are large proteins that help the flow chemical reactions. In addition, they make an effective washing powder based on them. They also provide tens of thousands of chemical reactions in living organisms. Enzymes (enzymes) are just as important to life as DNA - our genetic material cannot replicate itself without them.

The first enzyme discovered was amylase, also called diastase, and it's in your mouth right now. It breaks down starch into sugar and was discovered by the French industrial chemist Anselme Payen in 1833. He isolated the enzyme, but the mixture was not very pure. Long time biologists thought that extracting the pure enzyme might not be possible.

It took almost 100 years for the American chemist James Batchler Sumner to prove them wrong. In the early 1920s, Sumner began isolating the enzyme. His goals were so audacious that they actually cost him the friendship of many of the leading experts in the field, who thought his plan would fail. Sumner continued and in 1926 isolated urease, an enzyme that breaks down urea into its chemical components. Some of his colleagues doubted the results for years, but in the end they, too, had to give up. Sumner's work won him the Nobel Prize in 1946.

The assumption that all life has a common ancestor

Who was the first to suggest that all life evolved from a single creature? You will say: of course, Charles Darwin. Yes, Darwin developed this idea - in his "Origin of Species" he wrote the following: "There is a certain greatness in such a view of such a life, with its various manifestations, which was originally embodied in several forms or in one." However, while we are in no way minimizing Darwin's accomplishments, the idea of ​​a common ancestor was put forward decades earlier.

In 1740, the famous Frenchman Pierre Louis Moreau de Maupertuis suggested that "blind fate" produced a wide range of individuals, of whom only the most able survived. In the 1790s, Immanuel Kant noted that this could refer to the original ancestor of life. Five years later, Erasmus Darwin wrote: "Would it be too bold to assume that all warm-blooded animals are descended from a single living thread?". His grandson Charles decided that there was no "too much" and guessed.

Invention of cell staining

If you have ever seen photographs of cells taken with a microscope (or looked at them yourself), there is a very high chance that they were first stained. Coloring allows us to see those parts of the cell that are usually not visible, and generally increase the clarity of the picture. There are a bunch different methods cell staining, and this is one of the most fundamental techniques in microbiology.

The first person to color a specimen for examination under a microscope was Jan Swammerdam, a Dutch naturalist. Swammerdam is best known for his discovery of red blood cells, but he also made a career out of looking at everything under a microscope. In the 1680s, he wrote about the "colored liquor" of dissected worms, which "make it possible to better identify the internal parts, because they are of the same color."

To Swammerdam's regret, this text was not published for at least another 50 years, and by the time of publication Jan was already dead. At the same time, his fellow countryman and naturalist Anthony van Leeuwenhoek, independently of Swammerdam, came up with the same idea. In 1719 Leeuwenhoek used saffron to stain muscle fibers for further examination and is considered the father of this technique.

Development of cell theory

“Every living being is made up of cells” - this phrase is as familiar to us as “The Earth is not flat”. Today, cell theory is taken for granted, but in fact it was beyond our knowledge until the 19th century, 150 years after Robert Hooke first saw cells through a microscope. In 1824, Henri Duroche wrote of the cell: “It is evident that it is the basic unit of an ordered state; indeed, everything ultimately comes from the cell.”

In addition to being the basic unit of life, the cell theory also implies that new cells are formed when another cell divides into two. Duroce skipped this part (in his opinion, new cells form inside their parent). The final understanding that cells divide to reproduce is due to another Frenchman, Barthelemy Dumortier, but there were other people who made a significant contribution to the development of ideas about cells (Darwin, Galileo, Newton, Einstein). The cell theory was created in small bits, in much the same way as modern science is today.

DNA sequencing

Until his recent death, British scientist Frederick Sanger was the only living person to win two Nobel Prizes. It was the work for the second prize that led to the fact that he got on our list. In 1980 he received the top science prize along with Walter Gilbert, an American biochemist. In 1977, they published a method to figure out the sequence of the building blocks in a DNA strand.

The significance of this breakthrough is reflected in how quickly the Nobel Committee rewarded scientists. Eventually Sanger's method became cheaper and simpler, becoming the standard for a quarter of a century. Sanger paved the way for revolutions in the fields of criminal justice, evolutionary biology, medicine, and more.

Discovery of viruses

In the 1860s, Louis Pasteur became famous for his germ theory of disease. But Pasteur's microbes were only half the battle. Early proponents of the germ theory thought that all infectious diseases were caused by bacteria. But it turned out that colds, flu, HIV and other endless health problems are caused by something completely different - viruses.

Martinus Beijerinck was the first to realize that not only bacteria are to blame for everything. In 1898, he took juice from tobacco plants suffering from the so-called mosaic disease. Then I filtered the juice through a sieve so fine that it should have filtered out all the bacteria. When Beijerinck anointed healthy plants with juice, they got sick anyway. He repeated the experiment - and still got sick. Beijerink concluded that there was something else, perhaps a liquid, that was causing the problem. He called the infection vivum fluidum, or soluble living bacteria.

Beijerink also picked up the old English word "virus" and gave it to the mysterious agent. The discovery that viruses were not liquid belongs to the American Wendell Stanley. He was born six years after the discovery of Beijerinck and, apparently, immediately understood what needed to be done. Stanley shared the 1946 Nobel Prize in Chemistry for his work on viruses. Remember who you shared with? Yes, with James Sumner for work on enzymes.

Rejection of preformism

One of the most unusual ideas in history was preformism, once the leading theory about the creation of the baby. As the name implies, the theory suggested that all creatures were pre-created - that is, their form was already ready before they began to grow. Simply put, people believed that a miniature human body was inside every sperm or egg looking for a place to grow. This tiny little man was called a homunculus.

One of the key proponents of preformism was Jan Swammerdam, the inventor of the cell-staining technique discussed above. The idea was popular for hundreds of years, from the middle of the 17th century until the end of the 18th.

An alternative to preformism was epigenesis, the idea that life arises in a series of processes. The first person to put forward this theory against the backdrop of a love of preformationism was Caspar Friedrich Wolff. In 1759, he wrote an article in which he described the development of an embryo from several layers of cells to a person. His work was highly controversial at the time, but the development of microscopes put everything in its place. Embryonic preformism died far from being in the bud, but it died, pardon the pun.

Ten Biggest Achievements of the Decade in Biology and Medicine Independent Expert's Version

New high-throughput DNA sequencing methods - the "price" of the genome is falling

MicroRNA - what the genome was silent about

New high-throughput DNA sequencing methods - the "price" of the genome is falling

One of the founders of the famous company "Intel" G. Moore at one time formulated an empirical law, which is still fulfilled: the performance of computers will double every two years. The performance of DNA sequencers, which are used to decipher the nucleotide sequences of DNA and RNA, is growing even faster than according to Moore's law. Accordingly, the cost of reading genomes is falling.

Thus, the cost of work on the project "Human Genome", which was completed in 2000, amounted to 13 billion dollars. New mass sequencing technologies that appeared later were based on the parallel analysis of many DNA fragments (first in microwells, and now in millions of microscopic drops). As a result, for example, deciphering the genome of the famous biologist D. Watson, one of the authors of the discovery of the DNA structure, which in 2007 cost $2 million, only two years later “cost” $100,000.

In 2011, Ion torrent, which offered new method sequencing based on measuring the concentration of hydrogen ions released during the operation of DNA polymerase enzymes, read the genome of Moore himself. And although the cost of this work was not disclosed, the creators of the new technology promise that the reading of any human genome should not exceed $1,000 in the future. And their competitors, the creators of another new technology, nanopore DNA sequencing, already this year presented a prototype of a device on which, by spending several thousand dollars, it is possible to sequence the human genome in 15 minutes.

Synthetic biology and synthetic genomics - how easy it is to become God

Information accumulated over half a century of development molecular biology, today allows scientists to create living systems that have never existed in nature. As it turns out, this is not difficult to do, especially if you start with something already known and limit your claims to such simple organisms as bacteria.

Nowadays, there is even a special iGEM (International Genetically Engineered Machine) competition in the USA, in which student teams compete to come up with the most interesting modification of common bacterial strains using a set of standard genes. For example, transplanted into the well-known Escherichia coli ( Escherichia coli) a set of eleven specific genes, it is possible to make colonies of these bacteria, growing in an even layer on a Petri dish, change color consistently where light falls on them. As a result, it is possible to obtain their original “photographs” with a resolution equal to the size of a bacterium, i.e., about 1 micron. The creators of this system gave it the name "Koliroid" by crossing the species name of the bacterium and the name of the famous Polaroid company.

This area also has its own megaprojects. So, in the company of one of the fathers of genomics, K. Venter, the genome of a mycoplasma bacterium was synthesized from individual nucleotides, which is not similar to any of the existing mycoplasmal genomes. This DNA was enclosed in a “ready-made” bacterial shell of a killed mycoplasma and a working one was obtained, i.e. a living organism with a completely synthetic genome.

Medicines for aging - the way to "chemical" immortality?

No matter how many people have tried for thousands of years to create a panacea for aging, the legendary remedy of Makropoulos has remained out of reach. But even in this seemingly fantastic direction, progress appears.

So, at the beginning of the last decade, resveratrol, a substance isolated from the skin of red grapes, produced a big boom in society. First, with its help, it was possible to significantly extend the life of yeast cells, and then to multicellular animals, microscopic nematode worms, fruit flies, fruit flies, and even aquarium fish. Then the attention of specialists was attracted by rapamycin, an antibiotic isolated for the first time from soil bacteria-streptomycetes from about. Easter. With its help, it was possible to extend the life of not only yeast cells, but even laboratory mice, which lived 10-15% longer.

By themselves, these drugs are unlikely to be widely used to prolong life: the same rapamycin, for example, suppresses the immune system and increases the risk infectious diseases. However, active research is now underway on the mechanisms of action of these and similar substances. And if it succeeds, then the dream of safe medicines ah for life extension may well come true.

The use of stem cells in medicine - we are waiting for a revolution

Today, the US National Institutes of Health Clinical Trials Database lists almost half a thousand studies using stem cells at various stages of research.

However, it is alarming that the first of them, concerning the use of cells nervous system(oligodendrocyte) for the treatment of spinal cord injury, was interrupted in November 2011 for an unknown reason. After that, the American company "Geron Corporation" - one of the pioneers in the field of "stem" biology, which conducted this study, announced the complete curtailment of its work in this area.

Nevertheless, I would like to believe that the medical application of stem cells with all their magical possibilities is not far off.

Ancient DNA - From Neanderthal Man to Plague Bacteria

In 1993, the film "Jurassic Park" was released, in which monsters walked on the screen, recreated from the remnants of DNA from the blood of dinosaurs, preserved in the stomach of a mosquito immured in amber. In the same year, one of the greatest authorities in the field of paleogenetics, the English biochemist T. Lindahl, stated that even under the most favorable conditions, DNA older than 1 million years cannot be extracted from fossil remains. The skeptic turned out to be right - dinosaur DNA remained inaccessible, but the advances in the technical improvement of methods for extracting, amplifying and sequencing younger DNA made over the past decade are impressive.

To date, the genomes of the Neanderthal man, the recently discovered Denisovan and many fossil remains have been completely or partially read. Homo sapiens, as well as mammoth, mastodon, cave bear ... As for the more distant past, DNA was studied from plant chloroplasts, whose age dates back to 300-400 thousand years, and DNA of bacteria 400-600 thousand years old.

Of the studies of more “young” DNA, it is worth noting the decoding of the genome of the strain of the influenza virus that caused the 1918 epidemic of the famous “Spanish flu”, and the genome of the strain of the plague bacterium that devastated Europe in the 14th century; in both cases, the materials for analysis were isolated from the buried remains of those who died from the disease.

Neuroprosthetics - human or cyborg?

These achievements belong more to engineering than to biological thought, but this does not make them look less fantastic.

In general, the simplest type of neuroprosthesis - an electronic hearing aid - was invented more than half a century ago. The microphone of this device picks up sound and transmits electrical impulses directly to the auditory nerve or the brainstem - thus it is possible to restore hearing even to patients with completely destroyed structures of the middle and inner ear.

The explosive development of microelectronics over the past ten years has made it possible to create such types of neuroprostheses that it is time to talk about the possibility of a quick transformation of a person into a cyborg. This is an artificial eye, acting on the same principle as a hearing aid; and electronic suppressors of pain impulses through the spinal cord; and automatic artificial limbs capable of not only receiving control impulses from the brain and performing actions, but also transmitting sensations back to the brain; and electromagnetic stimulators of brain areas affected by Parkinson's disease.

Today, research is already underway regarding the possibility of integrating different parts of the brain with computer chips to improve mental abilities. And although this idea is far from being fully implemented, the video clips showing people with artificial hands, confidently using a knife and fork and playing table football, are amazing.

Nonlinear optics in microscopy - see the invisible

From the physics course, students firmly grasp the concept of the diffraction limit: in the best optical microscope it is impossible to see an object whose dimensions are less than half the wavelength divided by the refractive index of the medium. At a wavelength of 400 nm (violet region of the visible spectrum) and a refractive index of about unity (like air), objects smaller than 200 nm are indistinguishable. Namely, this size range includes, for example, viruses and many interesting intracellular structures.

Therefore, in recent years, methods of nonlinear and fluorescent optics have been widely developed in biological microscopy, for which the concept of the diffraction limit is inapplicable. Now, using these methods, it is possible to study in detail the internal structure of cells.

Designer proteins - evolution in vitro

As in synthetic biology, we are talking about creating something unprecedented in nature, only this time not new organisms, but individual proteins with unusual properties. This can be achieved with the help of both advanced computer simulation methods and “in vitro evolution”, for example, by selecting artificial proteins on the surface of bacteriophages specially designed for this purpose.

In 2003, scientists from the University of Washington, using computer structure prediction methods, created the Top7 protein - the world's first protein, the structure of which has no analogues in nature. And on the basis of the known structures of the so-called "zinc fingers" - elements of proteins that recognize DNA sections with different sequences, it was possible to create artificial enzymes that cleave DNA in any known place. Such enzymes are now widely used as tools for manipulating the genome: for example, they can be used to remove a defective gene from the genome of a human cell and force the cell to replace it with a normal copy.

Personalized medicine - we get gene passports

The idea that different people and get sick, and must be treated differently, is far from new. Even if we forget about different sex, age and lifestyle and do not take into account genetically determined hereditary diseases, still our individual set of genes can uniquely influence both the risk of developing many diseases and the nature of the effects of drugs on the body.

Many have heard about genes, defects in which increase the risk of developing cancer. Another example concerns the use of hormonal contraceptives: if a woman carries the “Leiden” factor V gene (one of the proteins of the blood coagulation system), which is not uncommon for Europeans, she has a sharp increase in the risk of thrombosis, since both hormones and this gene variant increase blood clotting .

With the development of DNA sequencing methods, it has become possible to draw up individual genetic health maps: it is possible to determine which known variants of genes associated with diseases or with a response to medications, are present in the genome of a particular person. Based on this analysis, recommendations can be made on the most appropriate diet, on the necessary preventive examinations and on precautions when using certain drugs.

MicroRNA - what the genome was silent about

In the 1990s The phenomenon of RNA interference was discovered - the ability of small double-stranded deoxyribonucleic acids to reduce the activity of genes due to the degradation of messenger RNAs read from them, on which proteins are synthesized. It turned out that cells actively use this regulatory pathway, synthesizing miRNAs, which are then cut into fragments of the required length.

The first microRNA was discovered in 1993, the second one only seven years later, and both studies used a nematode Caenorhabditis elegans, which now serves as one of the main experimental objects in developmental biology. But then the discoveries rained down, as if from a cornucopia.

It turned out that miRNAs are involved both in human embryonic development and in the pathogenesis of oncological, cardiovascular, and nervous diseases. And when it became possible to simultaneously read the sequences of all the RNAs in a human cell, it turned out that a huge part of our genome, which was previously considered “silent” because it does not contain protein-coding genes, actually serves as a template for reading microRNAs and other non-coding RNAs.

D. b. n. D. O. Zharkov (Institute of Chemical
biology and fundamental medicine
SB RAS, Novosibirsk)­

Recent advances in biology have led to the emergence of completely new directions in science. Thus, the establishment of the molecular nature of the gene served as the basis for genetic engineering - a set of methods that make it possible to construct pro- and eukaryotic cells with a new genetic program. On this basis, industrial production of antibiotics, hormones (insulin), interferon, vitamins, enzymes and other biologically active drugs has been established.
Among the achievements of biology can be noted the description a large number species of living organisms that exist on Earth, the creation of cellular, evolutionary, chromosome theory, deciphering the structure of proteins and nucleic acids, etc. In practice, this contributed to an increase in the efficiency of agricultural production, the development of medicine, biotechnology, and the creation of the foundations for rational environmental management.

Those who follow advances in molecular biology You must have gotten used to the fact that in this young science, which has entered only the third decade of its existence, major discoveries are made often, even very often. Just 17 years ago, the American James Watson and the Englishman Francis Crick proposed a hypothesis about the structure of the DNA molecule, which, in their opinion, which was not shared, however, by the majority of biologists at that time, was the custodian of genetic information. Very soon, in a fantastically short time, the opinion of Watson and Crick that DNA does indeed carry a record of all the genes of an organism was experimentally proven. By the beginning of the sixties, it became clear that genetic information from DNA molecules is transferred to RNA molecules similar in structure to them. The latter are connected to special cell structures - ribosomes, in which protein synthesis occurs. A little earlier, G. Gamov (USA), F. Crick and others created a logically complete model of the genetic code. The most important thing was that it was strictly indicated why the cell needs genetic information (the synthesis of specific proteins, which determine the property of life and the possibility of carrying out diverse life functions). It was also shown how individual elements of the DNA molecule (according to Gamow, with which everyone agreed, triples of nucleotides located along the DNA chain) encode the structure of proteins synthesized in ribosomes.
Few people expected - even among very astute geneticists - that already in 1961 Crick and his three assistants would "deal with" the problem of the general nature of the genetic code. True, the path to deciphering the composition of individual triplets encoding amino acids was opened by the work of M. Nirenberg and D. Mattei, reported in Moscow in the summer of the same 2000. And it was absolutely difficult to assume that in just two and a half years the Americans M. Nirenberg and F. Leder would offer a method that would allow us to find out the exact structure of all 64 code words of genes. A year later, geneticists knew the hereditary alphabet of nature.

But the solution of these problems did not increase our knowledge of the exact structure of the gene, the exact structure of the molecules of individual messenger and transport RNAs. In 1964-1965, Holly in the USA and A. Baev in the Russian Federation deciphered the first, smallest of the molecules that serve the genetic mysteries - the molecules of transport RNA. In 1967, in the laboratory of A. Kornberg in the USA, after many years of unsuccessful attempts, it was possible to synthesize an efficient DNA molecule of the 0X174 phage. A year later, G. Korana (an Indian who moved to the United States) in an ingenious experiment managed to synthesize the first gene for yeast transfer RNA. And now, just a year later, a pure gene has been isolated from the living DNA molecules!
Paradoxically, this experiment, grandiose in its design, implementation and consequences for science, was not an end in itself. Beckwith, a well-known specialist in the field of the molecular basis of the realization of genetic information, in the preface indicates the main goal that he and his colleagues pursued when starting work. It was important for them to find the keys to resolving the long-standing dispute about when the regulation of gene activity occurs. There were two propositions. According to the first, the ten itself (that is, a segment of DNA with a strictly defined sequence of nucleotides) can be the arena of regulation. In this case, messenger RNA will be written off from the activated genes, and such writing off will not occur from the repressed genes.

Thus, Biology is a rather young, but rather progressive science, quite useful for a person.

MEDICINE IN THE XX CENTURY

v 1901- Landsteiner discovered blood groups, the beginning of blood transfusion.

v 1904 - The Nobel Prize in Physiology or Medicine was awarded to Ivan Petrovich Pavlov for his discovery of conditioned reflexes.

v 1906 - the first cadaveric cornea transplant.

v 1910 - Thomas Morgan discovered chromosomes - the organelles of heredity.

v 1912- Banting and Best discovered insulin and the cause of diabetes.

v 1926 - Meller discovered the mutagenic effects of radiation and chemicals.

v 1936 - the first enzymes were obtained in a crystalline state.

v 1944 - Oswald Avery and McLean McCarthy proved that isolated DNA is integrated into the genome of bacteria, changing their phenotype.

v 1951 - the first coronary bypass surgery (coronary bypass).

v 1953 - James Watson and Francis Crick discovered the DNA double helix.

v 1955 - first kidney transplant.

v 1956 - the first coronary angioplasty.

v 1961 - Marshall Nirenberg deciphered the genetic code (dictionary) of DNA. The first hematogenous stem cell transplants to save doomed patients.

v 1964 - Charles Janowski confirmed the linear correspondence of genes and proteins of bacteria.

v 1967 - first heart and liver transplant.

v 1969 - A group of researchers from Harvard Medical School isolated the first human gene.

v 1974 - Stanley Cohen and Herbert Boyer transplanted the frog gene into a bacterial cell. The beginning of genetic engineering.

v 1976 - the first biotechnology company Genentech is created; transplantation of human genes into microorganism cells for the industrial production of insulin, interferon and other useful proteins began.

v 1980 - Martin Klein created the first transgenic mouse by transplanting a human gene into a fertilized mouse egg.

v 1982 - genetically engineered insulin produced by bacteria is approved for use in medicine.

v 1983 - polymerase chain reaction (a technique for multiple cloning of short DNA chains) was discovered - it became possible to simultaneously study the work of many genes.

v 1985 - the technique of "genetic fingerprinting" of DNA began to be used in world forensics.

v 1985 - the first transplants of fetal nervous tissue for the treatment of Parkinson's disease.

v 1988 - the first patent for a genetically modified animal is issued.

v 1990 - the beginning of work on the international project of the Human Genome.

v 1997 - cloned the first mammal - a sheep named Dolly; followed by successful cloning experiments in mice and other mammals.

v 1997-1998 - isolation of human embryonic stem cells as immortal lines.

v 1998 - creation of methods for simultaneous registration of the activity of 1000-2000 genes in the genome of humans and mammals.

v 1999-2000 - full transcript genome of 10 bacteria, yeast. Identification and location of half of the genes in human chromosomes.

v 2001 - complete transcription of the human genome

CLONING CHRONOLOGY

v 1883 - the discovery of the egg by the German cytologist Oskar Hertwig (Hertwig, 1849-1922).

v 1943 - The magazine "Science" reported on the successful fertilization of the egg "in vitro".

v 1953 - R. Briggs and T. King reported on the successful development of the "nucleotransfer" method - the transfer of the cell nucleus into giant eggs of the African clawed frog "xenopus".

v 1973 - Professor L. Shetles from Columbia University in New York announced that he was ready to give birth to the first "test tube baby", followed by categorical prohibitions from the Vatican and the Presbyterian Church of the USA.

v 1977 - the publication of a series of articles on the work of Oxford University Zoology Professor J. Gurdon ended, during which more than fifty frogs were cloned. Nuclei were removed from their eggs, after which the nucleus of a somatic cell was transplanted into the remaining "cytoplasmic sac". For the first time in the history of science, a diploid nucleus of a somatic cell with a double number of carriers of genetic information was introduced in place of the haploid nucleus of an egg cell with a single set of chromosomes.

v 1978 - the birth in England of Louise Brown, the first child "from a test tube".

v 1981 - Shetles receives three cloned human embryos (fetus), but stops their development.

v 1982 - Karl Ilmensee of the University of Geneva and his colleague Peter Hoppe of Jackson's laboratory in Bar Harbor, Maine, which has been breeding mice since 1925, obtained gray mice by transferring the nuclei of cells from a gray embryo into the cytoplasm of an egg cell obtained from a black female , after which the embryos were transferred to white females, which carried offspring. The results were not replicated in other laboratories, leading to Ilmensee's accusation of falsification.

v 1985 - January 4, in one of the clinics in North London, a girl was born to Mrs. Cotton - the world's first surrogate mother who is not a biological mother (that is, "baby Cotton", as the girl was called, was not conceived from Mrs. Cotton's egg). A parliamentary ban was issued on experiments with human embryos older than fourteen days.

v 1987 - specialists from the University of George Washington, using a special enzyme, managed to divide the cells of the human embryo and clone them to the stage of thirty-two cells (blasts, blastomeres), after which the embryos were destroyed. The American administration threatened to deprive laboratories of subsidies from federal funds if such experiments were carried out in them.

v 1996 - March 7, Nature magazine publishes the first article by a team of authors from the Roslin Institute in Edinburgh, who reported the birth of five lambs obtained without the participation of a ram: nuclei of a culture of embryonic cells obtained from another embryo were transferred into the cytoplasmic egg sacs. The Bill Clinton administration reaffirms its intention to withhold federal funds from anyone who intends to experiment with human embryos; thus, a researcher at the University of Washington was deprived of subsidies, who carried out the analysis of the sex of the embryo and the analysis of defective genes at the eight-cell stage.

v 1997 - On February 27, Nature featured on its cover - against a micrograph of an ovum - the famous sheep Dolly, born at the same Roslin Institute in Edinburgh. At the end of June, Clinton submitted a bill to Congress prohibiting "the creation of a human being by cloning and nuclear transfer of somatic cells."

v 1997 - at the very end of December, Science magazine reported the birth of six sheep obtained by the Roslin method. Three of them, including Polly the sheep, carried the human gene for “factor IX” (“factor 9”), or a hemostatic protein, which is necessary for people suffering from hemophilia, that is, blood incoagulability.

v 1997 - Michael Smith's book "Clones" is published in the USA, which tells about the cloning of people in underground tunnels around Los Angeles (see "Knowledge is Power", 1998, No. 4).

v 1998 - Chicago physicist Sid announces the creation of a laboratory for human cloning: he claims that he will not end up with clients.

v 1998, early March - French scientists announced the birth of a cloned heifer.

v 1999. Dutch scientists intend to clone the mammoth. To do this, they use the genetic material of a prehistoric mammal recently found in Siberia that died 20,380 years ago.

v 2000. In the laboratory of the Kagoshima Prefectural Institute of Agriculture, a cloned calf was born from the cell of an already cloned bull. This calf thus became the first animal of the second generation of clones of relatively large mammals.

v 2000. British scientists who cloned Dolly the sheep created five piglets using the same method.

v 2001. American scientists declare the fundamental possibility of human cloning. The House of Lords of the British Parliament, after many hours of debate, approved a bill allowing the cloning of human embryos

CHRONICLE OF DISCOVERIES IN CHEMISTRY

v 2500 - 2000 BC e. Penetration of copper from the East to Europe. Scales were invented in Babylon - a tool for measuring the amount of gold and other materials. The yoke of a weight-bearer served as a prototype for them.

v 2000 - 1500 BC e. AT Egyptian pyramids samples of glass and malleable iron were found.

v 1300 - 1000 BC e. AT Ancient Greece copper, iron, tin, lead, hardening of steel and the effect of manure as fertilizers are known.

v 1 in. BC e. In the poem "On the Nature of Things" by Lucretius Cara, invisible atoms are opposed to non-existent gods, with the help of which the whole variety of phenomena of the surrounding world is explained, including winds and storms, the spread of odors, evaporation and condensation of water.

v 700 - 1000 The Arab alchemist Jabir ibn Hayyan and his followers, as a result of unsuccessful attempts to turn base metals into gold, applied crystallization and filtration in the purification of chemicals; described the production of sulfuric, nitric, acetic acid and aqua regia (pointed to its ability to dissolve gold); prepared silver nitrate, sublimate, ammonia and white arsenic (arsenic acid).

v 1000 - 1200 In The Book of the Scales of Wisdom, the Arab scholar Al-Kazini cites specific gravity 50 different substances. In the "Book of Secrets" Abu-ar-Razi for the first time all substances are classified into earthy (mineral), vegetable and animal; calcination (roasting) of metals and other substances, dissolution, sublimation, melting, distillation, algamation, thickening, etc. are described.

v 1280. Arnaldo Villanovansky described the preparation of essential oils.

v 1300 - 1400 monk Berthold Schwarz is credited with the invention of gunpowder (in Europe). (In China, gunpowder was known at the beginning of our era).

v 1452 - 1519 The great Italian artist Leonardo da Vinci, by burning a candle under a vessel overturned over water, proves that air is consumed during combustion, but not all.

v 16th century The alchemist Vasily Valentin in the treatise "The Triumphal Chariot of Antimony" describes hydrochloric acid, antimony, bismuth (obtaining and properties); developed ideas that metals consist of three "beginnings": mercury, sulfur and salt.

v 1493 - 1541 Paracelsus transforms alchemy into iatrochemistry, believing that the main task of chemistry is to serve medicine as the manufacture of medicines. From him comes the first, repeatedly repeated observation that air is needed for combustion, and metals, when turned into scales, increase their weight.

v 1556. The work of G. Agricola "12 books on metals" summarizes information about ores, minerals and metals; metallurgical processes and subtleties of mining are described in detail; the systematics of metals according to external features is given.

v 1586 - 1592 G. Galileo designed a hydrostatic balance to determine the density of solids (1586), invented a thermometer (1592).

THE BIRTH OF SCIENTIFIC CHEMISTRY

v 1660 - 65 years. R. Boyle in the book "Skeptic Chemist" formulated the main task of chemistry (the study of the composition of various bodies, the search for new elements), developed an understanding of the concept of " chemical element and emphasized the importance of the experimental method in chemistry. He introduced the term "analysis" in relation to chemical research, established the inverse proportion of air volume to pressure, and applied indicators to determine acids and bases.

v 1668. O. Takheny introduced the concept of salt as a product of the interaction of an acid with an alkali.

v 1669. H. Brandt isolated phosphorus as a product of the distillation of urine (the first dated discovery of the element).

v 1675. N. Lemery defined chemistry as the art of "separating various substances contained in mixed bodies" (mineral, vegetable and animal).

v 1676. E. Mariotte expressed the dependence of air volume on pressure.

v 1707. I. Betger received white phosphorus.

v 1721. I. Genkel received metallic zinc.

v 1722. F. Hoffman described the production of hydrogen sulfide.

v 1723. G. Stahl proposed the theory of phlogiston as the material principle of combustibility.

v 1724. D. Fahrenheit discovered the dependence of the boiling point of water on pressure and the phenomenon of supercooling of water.

v 1730 - 33 years. R. Reaumur invented an alcohol thermometer (1730). He showed that solutions of different composition have different densities (1733).

v 1735. G. Brandt discovered cobalt.

v 1741 - 50 years. M. V. Lomonosov defined the element (atom), corpuscle (molecule), simple and mixed substances, and began developing his corpuscular theory (1741). He formulated the main provisions of the molecular-kinetic theory of heat (1744). He discovered the law of conservation of the mass of substances (1745). Observed the phenomenon of passivation of metals in conc. HNO3

v 1751. A. Cronstedt discovered nickel.

v 1757. D. Blake showed that carbon dioxide is released during fermentation.

v 1763. M. V. Lomonosov outlined the basics of mining and assay art, described methods for obtaining metals from ores.

v 1766. G. Cavendish discovered hydrogen.

v 1768. A. Baume invented a device for determining the density of liquids - a hydrometer.

v 1772. D. Rutherford discovered nitrogen.

v 1772 - 73 years. J. Priestley discovered hydrogen chloride, "laughing gas" (N 2 O) (1772), oxygen ("dephlogisticated air"), described the properties of ammonia (1773).

v 1774. A. Lavoisier suggested that atmospheric air has a complex composition. K. Scheele discovered manganese, barium, described the properties of chlorine.

v 1775 - 77 years. A. Lavoisier (independently of J. Priestley) discovered oxygen, described its properties, and formulated the foundations of the oxygen theory of combustion.

v 1778 - 81 years. K. Scheele discovered molybdenum, tungsten; received glycerin, lactic acid, hydrocyanic acid and acetaldehyde.

v 1781. G. Cavendish showed that water is formed during the combustion of hydrogen.

v 1782. J. Müller von Reichenstein discovered tellurium.

v 1785. T. E. Lovitz discovered the phenomenon of adsorption by charcoal from solutions.

v 1787. A. Crawford and W. Cruikshank discovered strontium. J. Charles established the equation for the dependence of gas pressure on temperature.

v 1789. M. Klaproth discovered zirconium and uranium.I. Richter formulated the law of equivalents.

v 1794. Yu. Gadolin discovered yttrium, which marked the beginning of the chemistry of rare earth elements.

v 1796. S. Tennart and W. Wollaston proved that diamond consists of carbon.

v 1797. L. Vauquelin discovered chromium.

v 1798. T. E. Lovitz introduced the concept of a supersaturated solution.

v 1800. W. Nicholson and A. Carlyle carried out the electrolysis of water.