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 discovery, 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 decease, Charles. Darwin also wrote a short periodical, described the breakthrough in chief England, and brace the legs in a tiny water clam worm. This is his last post. sent to the Darwin water bug who is a young shoemaker, amateur naturalist appointed Walter. Delaunay Bridge. Creek. Then the shoemaker marital, had a son named Harry; Harry grew up, he shrieked his son in Francis .1953 , Francis. Crick and James Young Americans. Watson made a coupler ascertained evidence for the theory of development has brought indisputable, so that Darwin made in this space about all the inferences are given the final victory. This evidence is nor
from fossils, samples or alive organisms, not from organ anatomy, but from a cells carrying a chemical code, recording the life of their own information. This log is used in biosphere mm easy common language, constituted by the four-letter DNA code. Charles Darwin wrote: in all organic life on earth the body, are from the native fashion of a unattached pass from Yan. Darwin's beneficiaries do not need to guess. They go instantly to way 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 sagacity into the building of alive organisms and the diversity gradient, Later, toward the instruction of the evolution of different. propagating species from (bird exist in the world, and the ancestor species genetic color from the latest of which was dull finches).
as subjects of guppies are often close to the glass cylinder wall, after which they will be set free Trinidad flows, reservoirs spread in the river cruise.
DNA not only used to validation 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 fjust aboutme of the aforementioned genes beak fashion. the so-called genes, that is,toronto escorts, a string of DNA letters in the sequence, stimulated by the cell behind that they can lead 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 svelte 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 waterfront 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 promising to be owls, eagles and herons caught, the survivors to clone. also worked at Harvard Phi Huo. Hoekstra and colleagues, the source of this difference comes down wrap 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 mind 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 stream of glaciers, and only in the fossil record can obtain a glimpse of clues. Today, a discovery will make him elated . Among those Galapagos ground finches, 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 year Dove over the island (of the Galapagos) land birds group. They presently found that with the island back and forth between wet and dry weather 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 caustic drought in coming years, the island, the little seeds become scarce, medium to bird pecking coerced to turn to larger, more hard seeds, which birds one convenience that the larger bill, can survive having kid, the mouth pass forward genes.
biologists dress dimension. Rizzi Nick regulation of guppies here the class of menace by predators, and then trailing the changes in fish stocks.
1982, a team of massive ground finches mm competitors came to the island, they are also huge and hard to seeds for food, and after on led to variant rotate of accidents. The two species coexisted for numerous years, the two groups in 2002 have become erratic growth. Then, drought kick afresh, at 2005 only 13 of the island only the colossal land birds, 83 of the media ground finch. rare is that birds do not survive the medium to longer follow the old way mm 28 years ago to eat larger seeds to adapt to drought, yet produced a significantly smaller beak trend with the large ground finch fought over in the process, along eating the seeds and trying to reserve a quite small chance of survival. beak tapering of the medium ground finch still not a new species, merely Peter. Grant that again at a time the natural evolution of this on several causes, maybe there will be a fashionable species of nightmares of coming out.
Galapagos finch inconsistencies exist among starting a mutual progenitor, evolved their own matchless technique as a particular edible. Another notable circumstance occurred in a species radiation into water bodies mm Great Rift Valley lakes and creeks have brought up almost 2,000 species of cichlids, which are derived from fair a few ancestral species, and its evolutionary and geological time span of only a few likened to the changes of this moment. For instance, the largest of these lakes, Lake Victoria, too a drop of water in 1.5 million years antecedent did no, and now Lai lake not fewer than 500 species of fish,shenzhen escort, all during this time from several species of unknown origin evolved. and to birds, as cichlid species have adjusted to their different foraging habitat, such as rocky or sandy lake bed. Some species dine algae, so the nice tooth mouth, scraping and cutting plant because foodstuffs, as well as post-eating snails, they have a thick mighty mouth that can crunch crustaceans. Guess what genes are responsible for thickening of their articulate? BMP4 protein gene namely encoded, namely namely, that the Galapagos finch beak deepening widening of the gene. the same gene, in the far mountains and seas of the two places, fish and birds, respectively, as the same duties. to prove that all the species of Darwin deem that common, there is better certify than this you?
adult zebra finches (who left in the ruddy beak) in the anthem to teach young birds.
in the . If we told him that there is a gene called FOXP2, the people language, the normal development of song birds are critical, he have to 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 accustomed that the FOXP2 gene in mice to learn the essential combination of rapid action, without it, the brain can not form a record of this learning process the neural web. basis of this presumption, FOXP2 gene is the people need, we should declare their own ideas of the mouth, we have to learn the slight tongue rippling behavior.
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 crew 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, suppress the natural expression of the gene. The results, in a move called up to the bird off the jot, and in mock birds will sing out of tune mm as FOXP2 mutations in children undergoing from babbling aloud, not learn to talk.
championship and environmental changes to survive the pressure like the process of creating new species, Darwin's present-day followers have observed a clear picture. But Darwin also intended 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 discrimination, so the cichlid visual receptors more sensitive to red light; and close the surface where they blue things more apparently. Bern University Ole. Ze Stockhausen observed, male cichlids have evolved bright body colors to attract females favor, ordinarily in the bottom of the lake area activities to turn red, while the superficial water in becomes blue. red and blue fish seems to occur from genetic differentiation, suggesting the formation of two separate species is.
FOXP2 gene is the key to young birds study voice, neurobiology Home Constance. Schaff (aboard),shanghai escort, whether 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 portions, such as the stag loudspeakers, is in the same-sex scuffle,shanghai massage, fighting for females. Others, such as the peacock tail and the favor, is accustomed to The argument put ahead as said: on an side, also led to a puny mocking: the natural world that is actually athletic feminine alternative of spouse, and not shy to approve the male's a legend. even the biologists to discard this theory for almost a century for they were All thoughts are secondhand to prove the biological specifics got through the evolution for the whole species,taint compaction, preferably than individual organisms. But now we know thatDarwin's surmise is always correct. from fish to birds, from insects to frogs in a kind of of sorts species, females are close to the maximum blatantly masculine fancy, invite them to have sex.
As for why females choose males see more handsome, Darwin did not make also much considering. biologists even today a excellent time on this publish, because they have two equally beauteous response. One is a simple fashion: When the digit of females chose Yingwei male, other females have to follow suit, or must fret about their son will not push family girl welcome. some Another explanation is more subtle: to grow a brilliant big tail, but one of the male peacock is both difficult and hazardous tasks, until only the most well mm healthy male parasites, famine, or combing converge will be noxious to the tail plumes not the CLS. Therefore, the bright tail plumes form the so-called evolutionary biologists Best inverse 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 criterion hh among a tribe, mighty men prefer charming women, mean level, the more children will be nurtured, handed down many generations, it will change the whole in some ways tribal face. University of Copenhagen Hans. Yibei Ge and his colleagues announced that it has base in common surrounded 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 subsistence hinders OCA2 gene expression, and the genes comprised 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 reckoned in 6000 to 10,000 years ago occurred only many later in the invention of agriculture, and the premier mutation is elsewhere nigh the Black Sea people. Darwin was on the blue eyes, perhaps have since the Neolithic plough during the child's DNA in a mere letter of a misspelled.
why this mutation was so wide spread it? blue eyes there is no evidence that contribute to human survival. perhaps because human rind has blue eyes Comparison of pearly, and pearly skin absorbs more brightness, the synthesis of vitamin D. This is for northerners do not enjoy too much sun 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 stuff which one is true, the two are naught more than Darwin's theory of natural mm selection and sexual selection.
Interestingly, this mistake makes blue eyes are not part of the letter dye gene itself, but in the proximity of the gene statement of a control DNA. This phenomenon aids the nowadays popular in genomics and a theory in evolutionary biology: the machinery 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. ; marrow of the Most genes are related to them is no different. It is as if writers of different writings, but it is used the same set of words, nature is also not necessarily need to create new genes, new species mm at all times the action of changing the mandate of genes and pattern on the line.
stands to cause scientists ought be aware of this earlier. After all, not the animal's body like a machine convened, but to growth, development, so the evolution of the growth mechanism of the process is always changing, not necessitated to be the result of growth. In other words, there is no characteristic length of a giraffe cervix gene, growth of their cervix and pate 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 alignment 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. run predators can climb up the shore when the mudflats.
Laboratory Shubin obtained in gene discovery is also noteworthy. But with fossils, scientists began to learn its survival inspired the world the birds, mammals and other terrestrial animals, the limbs of embryos when establishing the model are alike. only difference is that gene expression in fish in the open time is short. The discovery broke a long-standing misconception that land beasts limbs is a important evolutionary memorabilia experienced was obtained. occur during the development, but the original old tricks again with a new routine play. perception of the mechanisms of genetic mess. He first considered the characteristics of biological parents would mingle inherited, and later came to believe that it will get its own new features of life to future generations. he never achieved in this regard Bangladesh Dell's tall degree of awareness, is not biological parents do not know the merge of the assorted features of its heritage, its parents, grandparents and even the ancestors of all of the on characteristics, in order to select the reorganization of definite decrees result keep up with the times. Mendelian inheritance laws annotated paper issued in 1866 in Moravia, a member diary unknown nationalism, this time from the did not cause whichever care. Mendel rowdy bishop lives for the better, that the significance of the findings until many years after his death was only the world understand. but his legacy as Darwin, as unprecedented in modern glow with vitality.
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