The nine most important biological discoveries so far
Jul 17, 2018
1. can't see
Before 1675, people thought that the only living thing was what they could see. That year, a Holland businessman named Anthony van lvin van (Antony van Leeuwenhoek) discovered the microbiological world through self made microscope. Van Leeuwenhoek is the first person to see bacteria. Bacteria are described as small animals that move everywhere and everywhere. He discovered that a previously invisible universe not only brought people's world view into it, but also laid a foundation for understanding diseases caused by microbes.
2. the discovery of penicillin, the first antibiotic
Alexander Fleming (Alexander Fleming) discovered the antibacterial properties of penicillin in 1928, and there are few tools for preventing and treating bacterial infection. Fleming is working on some staphylococcal strains, when some of his dishes are contaminated by Penicillium. For Fleming's surprise, no matter where Penicillium grows on Petri dishes, mold can inhibit the growth of Staphylococcus.
The compound penicillin was purified from the mold for the first time to treat soldiers infected during World War II. Shortly after the war, miracle drugs were used to treat the general public, and some other antibiotics were also found.
3. protect people from smallpox
Is the idea of smallpox, measles, mumps and other diseases originated in ancient China? Chinese therapists will smash the scar removed from the smallpox survivor into powder and blow the dust into the nostril of the patient. Overall, these ancient healers are actually vaccinated to prevent the spread of the disease.
This practice laid the foundation for the late work of Edward Jenner, the first vaccine developed against smallpox in 1796. Smallpox vaccine is very effective, and doctors can eradicate the disease completely. Imagine: a disease that killed millions of people has disappeared completely. (now, using the same strategy can be very close to eradicating poliomyelitis!)
4. define the DNA structure
James Watson (James Watson) and Francis Click (Francis Crick) know how to capture code in the structure of DNA molecules and open up an understanding of how DNA carries a protein blueprint. They propose that DNA is composed of two nucleotides running in opposite directions and linked by hydrogen bonds between nitrogen groups. Using metal plates to represent bases, they built giant models that were almost immediately accepted as the right DNA.
5. looking for and combating defective genes
In August 24, 1989, scientists announced the first known cause of their discovery of hereditary diseases: they found a tiny deletion from a gene on chromosome 7, leading to fatal genetic disease cystic fibrosis. Identification of genetic defects, recognizing that this defect causes disease, opens the gate for genetic research.
Since then, other diseases such as Huntington's disease, hereditary breast cancer, sickle cell anemia, Down's syndrome, sicky disease, hemophilia, and muscular dystrophy have been found. Genetic tests of these diseases can be used to detect whether unborn babies have defective genes, or whether two potential parents are likely to produce affected infants. And knowing the causes of these diseases enable researchers to focus on possible ways to cure diseases.
6. the discovery of the principles of modern genetics
In the middle of nineteenth Century, Gregor Mendell, a Austria monk, used Gregor Mendel as a genetic basis for pea plants as a basis for genetic concepts. Because pea plants have many observable features - smooth peas and wrinkled peas, tall plants and short plants, and so on - Mendel can observe the results of mating pollen and planting a variety of pea plants.
Through his experiments, Mendel could be sure that hereditary factors were transferred from parents to offspring and remained unchanged in the offspring, so that they could be passed on to the next generation again. Although his work is done before the discovery of DNA and chromosomes, Mendel's first defined advantages, isolation and independent classification of genetic principles are still used today.
7.The theory of evolution of natural selection
Charles Darwin's study of giant tortoises and finches in Galapagos Islands led to his famous theory of natural selection, also known as the "survival of the fittest", published in a book entitled "origin of species" published in 1859. The main point of Darwin's theory is that organisms with better adaptability to their living conditions are more likely to survive and reproduce and transmit their characteristics to future generations.
These more suitable variants tend to thrive in a given area, while the inappropriate changes of the same species will not be good or just died. Therefore, as time goes on, the characteristics seen in the biological group in a given area may change. The importance of Darwin's natural selection theory can be seen today in the evolution of antibiotic resistant bacterial strains.
8. the formulation of cell theory
In 1839, zoologist Theodore Schwan (Sodor Schwann) and botanist Mathias Schleiden (Matthias Schleiden) were speaking at a dinner on their research. Theodore and Schwann were shocked by the fact that he had described the plant cells that he had been studying, and their resemblance to animal cells. The similarity between the two cells leads to the formation of cell theory, which includes three main ideas:
All creatures are made from cells.
Cells are the smallest units in biology.
All cells come from the preexisting cells.
9. amplification of DNA with PCR
In 1983, Kary Mullis discovered polymerase chain reaction (PCR).