Commemorate the 200th anniversary of Darwin's Teachers

 Darwin in the twenty-first century
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Photo: Lynn. Johnson LYNN JOHNSON
translation: Wang Xiaobo
two mice, one gray, one dark brown, the same species. they are Discover the breakthrough, and gradually reveal genetic control of natural selection, creation of the mysteries of the world lives in Vientiane.
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to two weeks before his death, Charles. Darwin also wrote a short paper, described the discovery in central England, and clamp the legs in a little water clam worm. This is his last post. sent to the Darwin water bug who is a young shoemaker, amateur naturalist named Walter. Delaunay Bridge. Creek. Then the shoemaker married, had a son named Harry; Harry grew up, he called his son in Francis .1953 , Francis. Crick and James Young Americans. Watson made a joint found evidence for the theory of evolution has brought indisputable, so that Darwin made in this area almost all the inferences are given the final victory. This evidence is neither
from fossils, specimens or living organisms, not from organ anatomy, but from a cells carrying a chemical code, recording the life of their own information. This record is used in biosphere mm simple common language, constituted by the four-letter DNA code. Charles Darwin wrote: in all organic life on earth the body, are from the original form of a single pass from Yan. Darwin's successors do not need to guess. They go directly to access to genetic Some very long, others short and small. After he concluded that, despite these differences, but all are close relatives of the Galapagos finch. class insight into the structure of living organisms and the diversity gradient, Later, toward the direction of the evolution of different. breeding species from (bird exist in the world, and the ancestor species genetic color from the latest of which was blunt finches).
as subjects of guppies are constantly close to the glass cylinder wall, after which they will be set free Trinidad streams, ponds scattered in the river cruise.
DNA not only used to confirm the authenticity of biological evolution, but also from the most basic level, it demonstrated biological remodeling of the way. Recently, Al Hart of Harvard University. 阿布扎诺夫 and Harvard Medical School, Cliff. Tabin locked responsible for some of the aforementioned genes beak shape. the so-called genes, that is, a string of DNA letters in the sequence, activated by the cell after that they can guide the synthesis of a particular protein. 阿布扎诺夫 and Tabin found in bird embryos gradually formed in the jaw, when BMP4 protein that is responsible for synthesis of genes is activated (scientists the term expression Sparrow, a calmodulin gene expression make to become thin and long beak. The large cactus finch gene (Gconirostris) the most active, so that they can be stuck with a long beak for seeds cactus fruit eat.
offshore in the Gulf Coast, Florida, a group of islands, the beach mouse's coat color of mice than the continental United States to light. This gives them access to the beach in a better light camouflage mm grown too high-profile mice more likely to be owls, eagles and herons caught, the survivors to reproduce. also worked at Harvard Phi Huo. Hoekstra and colleagues, the source of this difference comes down coat to a gene in a letters change. a mere reduction of the mouse DNA letters to Mao Zhongsheng into pigment. the gene mutation from the beach island 5,000 years ago during the formation of the group is created. Darwin's greatest idea is that a variety of species, between close relatives Most feature a variety of differences caused by natural selection. Now, we finch beaks and fur mice into, you can literally see that natural selection at work, it changes the shape and the DNA sequences of various genes and its expression, so that organisms adapt to specific environments.
Darwin originally conceived, the pace of biological evolution as slow flow of glaciers, and only in the fossil record can get a glimpse of clues. Today, a discovery will make him happy . Among those Galapagos finch Darwin's modern followers see the evolution occurring in real time In 1973, Peter, Rose Mary. Grant, his wife (now at Princeton University) began to observe the annual Dove over the island (of the Galapagos) land birds group. They soon found that with the island back and forth between wet and dry climate change, to the evolution of birds from year to year in the rapidly advancing. For example, the first island only two long-term in this breeding ground finch, one of which is the medium ground finch (G. fortis), with small seeds for food .1977 severe drought in coming years, the island, the little seeds become scarce, medium to bird pecking forced to turn to larger, more hard seeds, which birds an advantage that the larger bill, can survive having children, the mouth pass along genes.
biologists wear dimension. Rizzi Nick regulation of guppies here the level of threat by predators, and then tracking the changes in fish stocks.
1982, a group of large ground finches mm competitors came to the island, they are also big and hard to seeds for food, and later on led to another turn of events. The two species coexisted for many years, the two groups in 2002 have become abnormal growth. Then, drought hit again, by 2005 only 13 of the island only the large land birds, 83 of the medium ground finch. rare is that birds do not survive the medium to longer follow the old path mm 28 years ago to eat larger seeds to adapt to drought, but produced a significantly smaller beak trend Lots of competition with the large ground finch in the process, by eating the seeds and trying to keep a very small chance of survival. beak narrowing of the medium ground finch still not a new species, but Peter. Grant that again as long as the natural evolution of this on several occasions, maybe there will be a new species of dreams of coming out.
Galapagos finch differences exist between starting a common ancestor, evolved their own unique technique for a particular food. Another famous case occurred in a species radiation into water bodies mm Great Rift Valley lakes and rivers have brought up about 2,000 species of cichlids, which are derived from just a few ancestral species, and its evolutionary and geological time span of only a few compared to the changes of this moment. For example, the largest of these lakes, Lake Victoria, also a drop of water in 1.5 million years ago did not, and now Lai lake no less than 500 species of fish, all during this time from several species of unknown origin evolved. and to birds, as cichlid species have adapted to their different foraging habitat, such as rocky or sandy lake bed. Some species eat algae, so the fine tooth mouth, scraping and tearing plant for foodstuffs, as well as post-eating snails, they have a thick powerful jaws that can crunch crustaceans. Guess what genes are responsible for thickening of their articulate? BMP4 protein gene is encoded, that is, that the Galapagos finch beak deepening widening of the gene. the same gene, in the distant mountains and seas of the two places, fish and birds, respectively, as the same duties. to prove that all the species of Darwin believe that common, there is better evidence than this you?
adult zebra finches (who left in the red beak) in the song to teach young birds.
in the . If we told him that there is a gene called FOXP2, the human language, the normal development of song birds are critical, he must be very happy to .2001, Simon. Fisher and colleagues at the University of Oxford found that mutations in this gene can cause defects in human language. Later, he also confirmed that the FOXP2 gene in mice to learn the essential combination of fast action, without it, the brain can not form a record of this learning process the neural network. basis of this speculation, FOXP2 gene is the human need, we should declare their own ideas of the mouth, we have to learn the delicate tongue rippling action.
Then, the Berlin Free University of Constance. Schaaf found young zebra finches learn song, when somewhere in the FOXP2 gene in the brain becomes more active. Schaaf's team to a devil's cutting-edge technology, with a special virus infected finch brain, the virus carrying part of the FOXP2 gene in the reverse sequence, inhibit the natural expression of the gene. The results, in a move called up to the bird off the mark, and in mimic birds will sing out of tune mm as FOXP2 mutations in children suffering from babbling aloud, not learn to speak.
competition and environmental changes to survive the pressure like the process of creating new species, Darwin's contemporary followers have observed a clear picture. But Darwin also proposed another evolutionary impetus mm sexual selection. vision of Lake Victoria cichlids compatible with the surrounding environment: in deep water, through the rays of the red end of spectrum bias, so the cichlid visual receptors more sensitive to red light; and near the surface where they blue things more clearly. Bern University Ole. Ze Stockhausen observed, male cichlids have evolved bright body colors to attract females favor, usually in the bottom of the lake area activities to turn red, while the shallow water in becomes blue. red and blue fish seems to occur from the genetic differentiation, suggesting the formation of two separate species is.
FOXP2 gene is the key to young birds learn voice, neurobiology Home Constance. Schaff (on), if that failure of this gene, the birds will sing aloud of Hu.
If natural selection is the survival of the fittest (those who create the word philosopher He is Bert. Spencer, not Darwin), then sexual selection is the decorative parts, such as the stag horns, is in the same-sex melee, fighting for females. Others, such as the peacock tail and the like, is used to The argument put forward as said: on one side, also led to a slight mocking: the natural world that is actually active female choice of spouse, and not shy to accept the male's a romance. even the biologists to reject this theory for almost a century because they were All thoughts are used to prove the biological characteristics obtained through the evolution for the entire species, rather than individual organisms. But now we know that Darwin's guess is always correct. from fish to birds, from insects to frogs in a variety of all sorts of species, females are close to the most blatantly male fancy, invite them to have sex.
As for why females choose males look more handsome, Darwin did not make too much thinking. biologists even today a great time on this issue, because they have two equally beautiful answer. One is a simple fashion: When the number of females selected Yingwei male, other females have to follow suit, or have to worry about their son will not move home girl welcome. some Another explanation is more subtle: to grow a gorgeous big tail, but one of the male peacock is both laborious and dangerous tasks, until only the most well mm healthy male parasites, starvation, or combing focus will be detrimental to the tail feathers not the CLS. Therefore, the bright tail feathers form the so-called evolutionary biologists Best opposite sex is even a female peacock, they unknowingly passed on to future generations the best genes.
Darwin also thought, maybe it is sexual selection created a racial distinction. individual species has its own beauty standard hh within a tribe, strong men choose attractive women, average level, the more children will be nurtured, handed down many generations, it will change the whole to some extent tribal face. University of Copenhagen Hans. Yibei Ge and his colleagues announced that it has found in common among all pure-bred blue-eyed gene mutations. this place is just a mutation change in mm from the letter A into G, at 15 the long arm of chromosome. its existence hinders OCA2 gene expression, and the genes involved in eye color to darken the pigment synthesis mechanism. Ai Beige to Danish DNA with the Turks and Jordanians of DNA compared This mutation is calculated in 6000 to 10,000 years ago occurred only much later in the invention of agriculture, and the first mutation is somewhere around the Black Sea people. Darwin was on the blue eyes, perhaps have since the Neolithic farm during the child's DNA in a mere letter of a misspelled.
why this mutation was so wide spread it? no evidence that blue eyes can help the survival of mankind. perhaps because human skin has blue eyes Comparison of white, and white skin absorbs more sunlight, the synthesis of vitamin D. This is not too much to enjoy the sun from the north is particularly important because grain in their diet increasing the proportion of vitamin D levels are very low. Another On the one hand, it may be that the geographical area of the opposite sex is just a soft spot for blue eyes, with this feature it easier to many children and grandchildren. no matter which one is true, the two are nothing more than Darwin's theory of natural mm selection and sexual selection.
Interestingly, this error makes blue eyes are not part of the letter pigment gene itself, but in the vicinity of the gene expression of a control DNA. This phenomenon supports the nowadays popular in genomics and a theory in evolutionary biology: the mechanism of evolution is not only to change the genes, gene activation and also to change the way off. University of Wisconsin, Sean. Carroll said: genetic changes, but to control developmental gene regulation by different. ; soul of the Most genes are related to them is no different. It is as if writers of different books, but it is used the same set of words, nature is also not necessarily need to create new genes, new species mm as long as the operation of changing the order of genes and pattern on the line.
stands to reason scientists should be aware of this earlier. After all, not the animal's body like a machine assembled, but to growth, development, so the evolution of the growth mechanism of the process is always changing, not required to be the result of growth. In other words, there is no specific length of a giraffe neck gene, growth of their neck and head of the same gene, and mice; Perhaps these genes is only open a long time to create a longer neck. < br> As Darwin's fossils from the armadillo, who the American ostrich and inspiration to birds, he inherited the mantle of scientists have a combination of genetic research and the study of fossils to understand the history of life .2004, Neil University of Chicago. Shubin and colleagues in the Canadian Arctic found a fossils 375 million years ago, this animal just right to make up the fish and terrestrial animals, the space between. They called it fins in the terrestrial animal bone and upper arm, forearm and even the wrist-one correspondence. escape predators can climb up the shore when the mudflats.
Shubin obtained in the genetics laboratory findings are also striking. But with fossils, scientists began to study its survival inspired the world the birds, mammals and other terrestrial animals, the limbs of embryos when building the model are similar. only difference is that gene expression in fish in the open time is short. The discovery broke a long-standing misconception that land animals limbs is a major evolutionary events experienced was obtained. occur during the development, but the original old tricks again with a new routine play. knowledge of the mechanisms of genetic mess. He first considered the characteristics of biological parents would mix inherited, and later came to believe that it will get its own new features of life to future generations. He has never been in this area did not reach Bangladesh Dell's high degree of awareness, is not biological parents do not understand the mix of the various features of its heritage, its parents, grandparents and even the ancestors of all of the above characteristics, in order to select the reorganization of certain laws result from generation to generation. Mendelian inheritance laws explained paper published in 1866 in Moravia, a membership journal unknown nationality, this time from the did not cause any concern. Mendel rough priest lives for the better, that the significance of the findings until many years after his death was only the world know. but his legacy as Darwin, as unprecedented in modern glow with vitality.