It’s quite simple to forget that the ideas that seem obvious to us today have been honed for centuries by a team of smart people, and not just come about. The fact that we take them for granted is just the tip of the iceberg of an interesting story. Let's dig a little deeper.

The realization that animals can disappear

If you walk along the beach and find an interesting pebble-fossil, you immediately realize that it may belong to a long-extinct species. The idea that species is becoming extinct 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 have to create something that could not survive?

George Cuvier was the first person to ask such a question. In 1796, he wrote an article on elephants in which he described African and Asian species. He also mentioned the third type of elephants, known to science only by its bones. Cuvier noted the key differences in the jaw shape of the third elephant and suggested that this species should be completely separate. The scientist called him 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 precedes ours and was destroyed as a result of a kind of catastrophe." He did not stop only on this revolutionary idea. Cuvier studied the fossils of other ancient animals - by simultaneously introducing the term "pterodactyl" - and found that once reptiles were the dominant species.

The first cells grown outside the body

If a biologist wants to study the internal workings of animal cells, it is much simpler if these cells are not part of the animal at this time. Currently, biologists cultivate wide strips of cells in vitro, which greatly facilitates the task. The first person to try to keep the cells alive outside the host’s body was Wilhelm Ru, 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 frog embryo tissues and was able to grow new nerve fibers on their basis, which he then kept alive for a month. Today, cell samples can be kept alive almost indefinitely - scientists are still experimenting with the cell tissues of 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 most important principles of modern biology, along with evolution, genetics, and cell theory. The basic idea fits into a short phrase: organisms regulate their internal environment. But, as in the case of other important concepts that can be put into a short and concise phrase - objects with masses 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.

For the first time, the idea of \u200b\u200bhomeostasis was put forward by Claude Bernard, a prolific scientist of the mid-19th century, who was not allowed to sleep by the glory 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 the death of Bernard.

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

Scientists who are ahead of their time often remain unrecognized, but Bernard's other work was enough to strengthen his reputation. Nevertheless, science took almost 50 years to verify, confirm and evaluate its most important idea. The record of him 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 enzyme isolation

As a rule, they learn about enzymes for the first time at school, but if you skipped classes, we’ll explain: these are large proteins that help chemical reactions. In addition, they are used to make effective washing powder. They also provide tens of thousands of chemical reactions in living organisms. Enzymes (enzymes) are just as important for life as DNA is - our genetic material cannot copy itself without them.

The first enzyme discovered was amylase, which is also called diastasis, and it is in your mouth right now. It breaks down starch into sugar and was discovered by French industrial chemist Anselm Payen in 1833. He isolated the enzyme, but the mixture was not very clean. For a long time, biologists have believed that extracting a pure enzyme may not be possible.

It took almost 100 years for the American chemist James Butcher Sumner to prove them wrong. In the early 1920s, Sumner began to isolate the enzyme. His goals were so daring that they actually cost him friendship with many leading experts in this field who thought his plan would fail. Sumner continued and in 1926 isolated urease, an enzyme that breaks down urea into chemical components. Some of his colleagues doubted the results for years, but in the end they had to give up. Sumner's work brought 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 one creature? You 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 this view of such a life, with its various manifestations, which was originally embodied in several forms or in one.” However, although we are not at all belittling Darwin's accomplishments, the idea of \u200b\u200ba common ancestor was voiced decades earlier.

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

The 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. Staining 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 of different methods for staining cells, and this is one of the most fundamental techniques in microbiology.

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

Unfortunately, this text has not been published for at least another 50 years, and by the time it was published, Jan was already dead. At the same time, his fellow countryman and naturalist Anthony van Levenguk independently of Swammerdam came to the same idea. In 1719, Levenguk used saffron for dyeing muscle fibers for further examination and is considered the father of this technique.

The development of cell theory

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

Besides the fact that the cell is the basic unit of life, the cellular theory also implies that new cells are formed by dividing another cell into two. Duroce skipped this part (in his opinion, new cells form inside his parent). The final understanding that cells divide for reproduction belongs to another Frenchman, Barthelemy Dumortier, but there were also other people who made a significant contribution to the development of ideas about cells (Darwin, Galileo, Newton, Einstein). Cellular theory was created in small amounts, roughly the same as modern science today.

DNA sequencing

Until the recent demise, the British scientist Frederick Sanger was the only living person who received two Nobel Prizes. It was work for the second prize that led to his being on the list. In 1980, he received a major science prize with Walter Gilbert, an American biochemist. In 1977, they published a method that allows you to find out the sequence of building blocks in a DNA strand.

The significance of this breakthrough is reflected in how quickly the Nobel Committee awarded scientists. Ultimately, the Sanger method became cheaper and simpler, became the standard for a whole quarter century. Sanger paved the way for revolutions in the areas of criminal justice, evolutionary biology, medicine, and many others.

Virus discovery

In the 1860s, Louis Pasteur became famous for his microbial theory of disease. But Pasteur's germs were only half the battle. Early advocates of microbial 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 Beyerink was the first to realize that not only bacteria are to blame for everything. In 1898, he took juice from tobacco plants, patients with the so-called mosaic disease. Then he filtered the juice through a sieve so small that it was supposed to filter out all the bacteria. When Beyerink anointed healthy plants with juice, they still got sick. He repeated the experiment - and still got sick. Beyerink concluded that there is something else, possibly a liquid, that causes problems. He called the infection vivum fluidum, or soluble living bacteria.

Beyerink also picked up the old English word "virus" and endowed them with a mysterious agent. The discovery that viruses were not liquid belongs to the American Wendell Stanley. He was born six years after the discovery of Beyerink and, apparently, immediately realized what to do. For work on viruses, Stanley shared the 1946 Nobel Prize in Chemistry. Remember who you shared with? Yes, with James Sumner for working on enzymes.

Rejection of Preformism

One of the most unusual ideas in history was preformism, once the leading theory of creating a 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 in search of 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 that we talked about above. The idea has been popular for hundreds of years, from the mid-17th century to 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 amid a love of preformism was Caspar Friedrich Wolf. 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 extremely controversial at that time, but the development of microscopes put everything in its place. Embryonic preformism did not die in the bud, but died, sorry for the pun.

Top Ten Achievements of the Decade in Biology and Medicine Independent Expert Version

New high-performance DNA sequencing methods - genome “price” falls

MicroRNA - what the gene was silent about

New high-performance DNA sequencing methods - genome “price” falls

G. Moore, one of the founders of the famous Intel company, once formulated an empirical law that is still being implemented: computer performance will double every two years. The performance of DNA sequencers, with the help of which the decoding of nucleotide sequences of DNA and RNA, is growing even faster than according to the "Moore's law". Accordingly, the cost of reading genomes falls.

Thus, the cost of carrying out work on the Human Genome project, which ended in 2000, amounted to $ 13 billion. 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 droplets). As a result, for example, the decoding of the genome of the famous biologist D. Watson, one of the authors of the discovery of the DNA structure, which cost $ 2 million in 2007, after only two years “cost” $ 100 thousand.

In 2011, Ion torrent, which proposed a new sequencing method based on measuring the concentration of hydrogen ions released during the work of DNA polymerase enzymes, read the genome of Moore himself. And although the cost of this work was not announced, 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, DNA sequencing in nanopores, already this year presented a prototype device on which, after spending several thousand dollars, you can sequence the human genome in 15 minutes.

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

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

Today in the United States there is even a special iGEM (International Genetically Engineered Machine) contest in which student teams compete on who can come up with the most interesting modification of ordinary bacterial strains using a set of standard genes. For example, transplanting into a well-known E. coli ( Escherichia coli) a set of eleven specific genes, it is possible to force the colonies of these bacteria, which grow evenly on the Petri dish, to stably change color where the light falls on them. As a result, you can get their kind of "photos" with a resolution equal to the size of the bacteria, that is, about 1 micron. The creators of this system gave it the name “Coliroid”, crossing the species name of the bacterium and the name of the famous company “Polaroid”.

There are also megaprojects in this area. So, in the company of one of the fathers of genomics, K. Venter was synthesized from individual nucleotides by the gene of the bacterium-mycoplasma, which is not similar to any of the existing mycoplasma genomes. This DNA was enclosed in a “prepared” bacterial membrane of the killed mycoplasma and got working, i.e. living organism with a fully synthetic genome.

Cures for aging - the path to "chemical" immortality?

No matter how many thousands of years they tried to create a panacea for aging, the legendary remedy of Makropoulos remained unattainable. But even in this seemingly fantastic direction, shifts are appearing.

So, at the beginning of the last decade, resveratrol, a substance isolated from the peel of red grapes, made a big boom in society. First, with its help, it was possible to significantly extend the life of yeast cells, and then multicellular animals, microscopic nematode worms, fruit flies, Drosophila and even aquarium fish. Then, the attention of specialists was attracted by rapamycin, an antibiotic first isolated from soil bacteria-streptomycetes from Fr. Easter. With its help, it was possible to extend the life not only of 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 of infectious diseases. However, active research is underway on the mechanisms of action of these and similar substances. And if this succeeds, then the dream of safe medicines for prolonging life may well come true.

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

Today, the database of clinical trials of the National Institutes of Health of the USA lists almost five hundred works using stem cells at different stages of the study

However, it is alarming that the first of them, concerning the use of cells of the nervous system (oligodendrocytes) for the treatment of spinal cord injuries, 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 that conducted this study, announced the complete curtailment of its work in this area.

Nevertheless, I want to believe that the medical use of stem cells with all their magical possibilities is just around the corner.

Ancient DNA - From Neanderthal to Plague Bacteria

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

Today, the genomes of the Neanderthal man, the recently discovered Denisovan and many fossil remains are fully or partially read. Homo sapiensas well as a mammoth, mastodon, cave bear ... As for the more distant past, we studied DNA from plant chloroplasts, whose age dates from 300-400 thousand years, and bacterial DNA from 400-600 thousand years old.

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

Neuro prosthetics - a person or a cyborg?

These achievements belong to engineering rather than biological thought, but from this they do not look less fantastic.

In general, the simplest type of neuro prosthesis - the electronic hearing aid - was invented even more than half a century ago. The microphone of this device picks up sound and transmits electrical impulses directly to the auditory nerve or to the brain stem - this way you can return the 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 neuro prostheses that it is just right to talk about the possibility of a person soon becoming 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 that can not only perceive the control impulses of the brain and perform actions, but also transmit sensations back to the brain; and electromagnetic stimulants of brain zones 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 it’s far from the full realization of this idea, video clips showing people with with artificial handsconfidently using a knife and fork and playing table football, are amazing.

Nonlinear optics in microscopy - see the invisible

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

Therefore, in recent years, methods of nonlinear and fluorescence optics, for which the concept of the diffraction limit is not applicable, have been widely developed in biological microscopy. Now, using such methods, it is possible to investigate in detail the internal structure of cells.

Designer proteins - in vitro evolution

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. One can wish for this with the help of both advanced computer simulation methods and “in vitro evolution” - for example, the selection of artificial proteins on the surface of bacteriophages specially created for this purpose.

In 2003, scientists from the University of Washington, using computer-assisted structural prediction methods, created the Top7 protein, the first protein in the world whose structure has no analogues in living nature. And on the basis of the well-known structures of the so-called “zinc fingers” - elements of proteins that recognize DNA fragments with different sequences, it was possible to create artificial enzymes that break down DNA in any place that is known to be. 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 human cell’s genome and force the cell to replace it with a normal copy.

Personalized medicine - get gene passports

The idea that different people get sick and should be treated differently is far from new. Even if you forget about different sex, age and lifestyle and do not take into account genetically determined hereditary diseases, still our individual set of genes in a unique way can affect both the risk of developing many diseases and the nature of the effect of drugs on the body.

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

With the development of DNA sequence determination methods, it became possible to compile individual genetic health maps: it is possible to establish what known variants of genes associated with diseases or with the response to drugs exist in the genome of a particular person. Based on this analysis, you can make recommendations about the most suitable diet, about the necessary preventive examinations, and about precautions when using certain drugs.

MicroRNA - what the gene was silent about

In the 1990s the phenomenon of RNA interference was discovered - the ability of small double-stranded deoxyribonucleic acids to reduce gene activity due to the degradation of matrix RNAs read from them, on which proteins are synthesized. It turned out that the cells actively use this way of regulation, synthesizing microRNAs, which are then cut into fragments of the desired length.

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

It turned out that miRNAs are involved 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 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 genes encoding proteins, actually serves as a matrix 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 by which it is possible to construct pro- and eukaryotic cells with a new genetic program. On this basis, the industrial production of antibiotics, hormones (insulin), interferon, vitamins, enzymes and other biologically active drugs has been established.
Among the achievements of biology, one can note a description of a large number of species of living organisms that exist on Earth, the creation of a cellular, evolutionary, chromosome theory, decoding of the structure of protein 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 basics of environmental management.

Those who follow advances in molecular biologyThey must have gotten used to the fact that in this young science, which entered only the third decade of its existence, major discoveries are made often, even very often. Only 17 years ago, American James Watson and the Englishman Francis Crick proposed a hypothesis about the structure of a DNA molecule, which, in their opinion, was not shared, however, at that time by most biologists, was the keeper of genetic information. Very soon, right in a fantastically short time, the opinion of Watson and Crick that DNA really carries a record of all the genes of the body was experimentally proved. By the beginning of the sixties, it became clear that genetic information from DNA molecules was transferred to RNA molecules similar in structure to them. The latter combine with special cell structures - ribosomes, in which protein synthesis takes place. A little earlier G. Gamow (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 needed genetic information (the synthesis of specific proteins, which determine the quality of life and the possibility of implementing diverse life functions). It was also shown how individual elements of a DNA molecule (according to Gamow, with which everyone agreed, the triplets of nucleotides located along the DNA chain) encode the structure of the proteins synthesized in ribosomes.
  Few expected - even among the very perceptive 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 triples encoding amino acids was discovered by the work of M. Nirenberg and D. Mattei, reported in Moscow in the summer of the same 2000. And it was very difficult to suppose that in just two and a half years, the Americans M. Nirenberg and F. Leder would propose a way to find out the exact structure of all 64 codewords of genes. A year later, geneticists knew the hereditary alphabet of nature.

But the solution of these problems did not increase our knowledge about the exact structure of the gene, the exact structure of the molecules of individual information and transport RNAs. In 1964-1965, Holly in the USA and A. Bayev in the Russian Federation deciphered the first, smallest of the molecules serving the genetic sacraments - transport RNA molecules. In 1967, in the laboratory of A. Kornberg in the USA, after many years of unsuccessful attempts, it was possible to synthesize a workable DNA molecule of phage 0X174. A year later, G. Koran (an Indian who moved to the USA) in a cunning experiment was able to synthesize the first gene for yeast transport RNA. And now, just a year later, a pure gene from living dNA molecules!
  Paradoxically, this grandiose experiment was not a goal in its design, implementation, and consequences for science. Beckwith, a well-known specialist in the field of molecular fundamentals of the realization of genetic information, in his introduction points to the main goal that he and his colleagues pursued when starting work. It was important for them to find the keys to resolving a long-standing debate about when the regulation of gene activity occurs. There were two. According to the first, the ten itself (that is, a DNA site with a strictly defined nucleotide sequence) may be the arena of regulation. In this case, informational RNA will be deducted from activated genes, and such deduction will not occur from repressed genes.

Thus, biology is quite young, but rather progressive science, quite useful for humans.

MEDICINE IN THE XX CENTURY

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

v 1904 - Ivan Petrovich Pavlov was awarded the Nobel Prize in the field of physiology and medicine for the discovery of conditioned reflexes.

v 1906 - the first transplant of a cadaverous cornea.

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

v 1912- Bunting 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 obtained in a crystalline state.

v 1944 - Oswald Avery and Maclean McCarthy proved that isolated DNA integrates into the bacterial genome, changing their phenotype.

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

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

v 1955 - the 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 transplant to rescue doomed patients.

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

v 1967 - the 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 a frog gene into a bacterial cell. The beginning of genetic engineering.

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

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

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

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

v 1985 - DNA genetic fingerprinting techniques began to be used in world forensics.

v 1985 - the first transplantation of fetal nerve tissue for the treatment of Parkinson's disease.

v 1988 - the first patent for a genetically modified animal was granted.

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

v 1997 - the first mammal was cloned - a sheep named Dolly; then successful experiments on the cloning of mice and other mammals followed.

v 1997-1998 - isolation of human embryonic stem cells in the form of immortal lines.

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

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

v 2001 - complete decoding of the human genome

CLONING CHRONOLOGY

v 1883 - the discovery of an egg by the German cytologist Oscar Gerwig (Herwig, 1849-1922).

v 1943 - Science magazine reported successful in vitro fertilization of an egg.

v 1953 - R. Briggs and T. King reported the successful development of the “nucleotransfer” method - transfer of the cell nucleus to the giant eggs of the African xenopus frog.

v 1973 - Professor L. Shetles of Columbia University in New York stated that he was ready to give birth to the first “baby tube”, followed by categorical prohibitions of the Vatican and the Presbyterian Church of the United States.

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

v 1978 - the birth in England of Louise Brown, the first “test tube” child.

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

v 1982 - Carl Ilmensee of the University of Geneva and his colleague Peter Hoppe of the Jackson Laboratory in Bar Harbor, Maine, in which mice have been bred since 1925, obtained gray mice by transferring the nuclei of gray embryonic cells to 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 reproduced in other laboratories, which led to the accusation of Ilmensee falsification.

v 1985 - January 4, in a clinic in northern 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 on experiments with human embryos older than fourteen days was passed.

v 1987 - Specialists at George Washington University, using a special enzyme, were able to separate 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 the laboratory of subsidies from federal funds if such experiments were conducted in them.

v 1996 - March 7, the journal Natural published the first article of a team of authors from the Roslyn Institute in Edinburgh, who reported the birth of five lambs obtained without the participation of a ram: the nuclei of the culture of embryonic cells received from another embryo were transferred to the cytoplasmic bags of the eggs. The Clinton administration once again reaffirms its intention to deprive federal funds of support to all who intend to experiment with human embryos; Thus, a researcher from the University of Washington, who analyzed the sex of the embryo and the analysis of defective genes at the stage of eight cells, was deprived of subsidies.

v 1997 - February 27, "Natural" placed on its cover - against the background of a micrograph of an egg - the famous sheep Dolly, born at the same Roslin Institute in Edinburgh. In late June, Clinton sent a bill to Congress prohibiting "creating a human being by cloning and nuclear transfer of somatic cells."

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

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 cloning people: he claims that he will have no end to customers.

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

v 1999 year. Dutch scientists intend to clone a mammoth. To do this, they use the genetic material of a prehistoric mammal recently discovered in Siberia, who died 20380 years ago.

v 2000 year. In the laboratory of the Agricultural Institute of Kagoshima Prefecture, a calf was cloned from the cage of an already cloned bull. This calf, thus, became the first animal of the second generation of clones of relatively large mammals.

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

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

CHRONICLES OF DISCOVERY IN CHEMISTRY

v 2500 - 2000 BC e. Penetration of copper from the East to Europe. In Babylon, scales were invented - a tool for measuring the amount of gold and other materials. The prototype of them was the rocker of the porter.

v 2000 - 1500 BC e. In the Egyptian pyramids found samples of glass and ductile iron.

v 1300 - 1000 years BC e. In 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 of Lucretius Cara "On the nature of things," invisible atoms are contrasted with non-existent gods, with the help of which the whole variety of phenomena of the world, including winds and storms, the spread of odors, evaporation and condensation of water, is explained.

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

v 1000 - 1200 years. In the "Book of the scales of wisdom," the Arab scholar Al-Qazini cites specific gravities   50 different substances. In the "Book of Secrets" Abu-ar-Razi for the first time all substances are classified into earthy (mineral), plant and animal; calcination (firing) 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 the monk Bertold Schwartz 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 tilted over water, proves that when burned, air is consumed, but not all.

v XVI century Alchemist Vasily Valentin in the treatise "Triumphal Antimony Chariot" describes hydrochloric acid, antimony, bismuth (production and properties); The idea that metals consist of three “principles”: mercury, sulfur, and salt is developed.

v 1493 - 1541 years. 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 combustion needs air, and metals when converted to scale increase their weight.

v 1556. In 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 taxonomy of metals by external features is given.

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

THE ORIGIN 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 the idea of \u200b\u200bthe 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 proportionality 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 acid with alkali.

v 1669. H. Brandt identified 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 the various substances contained in mixed bodies" (mineral, plant and animal).

v 1676. E. Marriott 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 the alcohol thermometer (1730). He showed that solutions of different composition have different densities (1733).

v 1735. G. Brandt discovered cobalt.

v 1741 - 50 years. MV Lomonosov gave a definition of an element (atom), corpuscle (molecule), simple and mixed substances and began the development of his corpuscular theory (1741). He formulated the basic principles of the molecular-kinetic theory of heat (1744) and discovered the law of conservation of mass of substances (1745). I observed the phenomenon of passivation of metals in conc. HNO 3

v 1751. A. Kronstedt discovered nickel.

v 1757. D. Blake showed that fermentation emits carbon dioxide.

v 1763. MV Lomonosov outlined the fundamentals of mining and assay art, described methods for producing 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, the “laughing gas” (N 2 O) (1772), oxygen (“de-logged 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, formulated the foundations of the oxygen theory of combustion.

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

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

v 1782. I. Muller von Reichenstein discovered tellurium.

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

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

v 1789. M. Klaprot 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. Vauclin discovered chrome.

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

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