Why do we have the "nature"?

<p> "Sex" come from? earlier hypothesis for biologists in the actual examples of original really have "Red Queen" </ p> <p> <wbr> </ p> <p> <wbr> </ p> < .p> </ p> <p> The Alice mirror adventures of illustration, content is the "Red Queen". </ p> <p> <wbr> <wbr> The same Lake small bellamya purificata like other complex animal baby, but .in "the women" in the "self-reliance", why such differences? recently, authoritative science site "Livescience," reports the United States scientists Curtis · Les Foley (CurtisM.Lively), Zhu card · Joe KELA (Jukka Jokela) .and mark · Tai da (MarkF.Dybdahl) research results, the name of "New Zealand marine snails" of animals strange breeding behavior may be the origin of "Red Queen" hypothesis provides direct evidence. </ p> <p> <wbr .> </ p> <p> "Lustful guest" and "women" </ p> <p> <wbr> </ p> <p> This New Zealand science named Potamopyrgusantipodarum marine snails. </ p> Belong to the Mollusca ., Gastropoda, suction snails. Its body length is only 5-12 mm. And we are familiar with snail, the snails in luoke opening a "cover", in physical condensation in a piece of crust covering the entrance. In the home of New .Zealand's marine snails Lakes, they are two completely different ways: some needless reproduction mating, can "clone" a small snails, just like our eating bellamya purificata, sometimes open luoke appears a little mother, eggs in bellamya purificata bellamya purificata body has been hatching .. But this kind of screw also has gender differences, male and female snails will, and snail mating with the seed of the "happy" to give birth to small snails. In other words, these snails have like a complex animal "Lust", .some of them completely "self-sufficiency". This way, New Zealand, marine snails is divided into two categories, one category is totally asexual populations, and the other is sexual reproduction and asexual mixed groups. <p> <wbr> </ .p> <p> <wbr> On this New Zealand marine snails of experiments confirmed the theory of the "Red Queen". </ p> <p> <wbr> </ p> <p> See New Zealand marine snails of the .strange situations, Indiana University Professor of Les Foley, perceptive flash light: scientists are looking for asexual and sexual reproduction coexistence groups, marine snails. </ p> <p> <wbr> </ p> <p> In fact, scientists have .been trying to understand what the "sex" is how the origin. </ p> Asexual reproduction in relation to sexual reproduction, the benefits are obvious: you can keep the change object mating, save energy and reduce the risk of male-female not .only, the children are unable to bear children; gene mutation factors except all is their own, not "like the father or mother," issues like. So, what are the benefits of sexual reproduction? scientists speculate sexual reproduction can mix both parents born .gene, so each child's genotype is different and more conducive to adapt to the ever-changing environment. Asexual reproduction of a "crowd" of sexual reproduction, and a "personalized" genotypes. To adapt to changing environments, "personality" is better than .the "crowd". However, sexual reproduction of this "strategic" benefits can offset the asexual advantage? why sexual reproduction in the biological survival competition eventually occupy the advantage that the vast majority of the Earth now Eukaryotes are taking sexual reproduction? to address this .problem, there are scientists put forward the theory of the "Red Queen". <p> <wbr> </ p> <p> The Red Queen's "debut" </ p> <p> <wbr> </ p> < .p> "The Red Queen 's" theory of the name is taken from the United Kingdom writer, mathematician Carol classic children's literature by the Alice mirror world adventures. </ p> This book is the Alice Carroll's follow-up. In this book ., a chess pawn Queen's "red." She wore a mad race to Alice, appears to be progressive, but remained in place. "Red Queen" theory and the book are very similar to the character's experience: biological groups long withstand the pressure of .the parasitic organisms, both trying to "race". It is this kind of pressure counterbalance asexual, sexual reproductive advantage gained the upper hand. <p> <wbr> </ p> <p> <wbr> Infected with the parasite's New Zealand .marine snails (top) and the health of individuals (below). </ p> <p> <wbr> </ p> <p> This theory is very beautiful, but has always suffered from a lack of examples, New Zealand, .marine snails sexual reproduction and the coexistence of species is asexual gave scientists excellent research objects, but exactly this species provides a "three-stage as a golden certificate". </ p> <p> <wbr> </ p> <p> .Over the past 20 years, Les Foley and colleagues have been studying New Zealand marine snails. </ p> He found that the sexual and asexual mixed groups there is a severe parasitic infection, at least 11 "fluke" kind of parasite infects New Zealand .marine snails, draw them on nutrition, let them produce a lot of cyst, serious impact on their life and reproductive capacity. Les Foley thinks that it is possible that these common fluke and marine snails, constantly evolving out of the "bandwagon" genotypes, .resulting in a "Red Queen" effect, control the number of asexual reproduction of marine snails, so that they cannot be completely replaced by sexual reproduction of marine snails. To prove this, Les Foley and his colleagues focused on New Zealand's Lake Alexandrina and Garnier .Lake marine snails. <p> <wbr> </ p> <p> <wbr> Experimental expanded site: New Zealand's Lake Alexandrina </ p> <p> Simple experiment to prove hypothesis </ p> <p> <wbr> .</ p> <p> They found that in shallow water, marine snails of sexual reproduction and, more prosperous, more than 4 metres deep, is asexual, marine snails. </ p> Scientists believe that this may be due to the shallow .water, suitable for parasites living here common parasites and marine snails, which controls the evolution ofAsexual reproduction in the number of individuals. And the reason for parasites live in shallow water, because the parasite must end its host - wild duck body complete last life cycle ., and the wild ducks only feeds in shallow water. <p> <wbr> </ p> <p> There is another possible explanation: live in shallow water snails for some reason is more vulnerable to parasites. </ p> So scientists .have to know how to live in the shallow water of the snail is only on local susceptibility of parasites, or to all the parasites in the Lake has a predisposition. If the former, you live in the shallow water of the snail is vulnerable to parasites .and the local common evolutionary result of parasites. <p> <wbr> </ p> <p> Scientists design of experiments is very simple, let the Repulse of marine snails in mixed reproductive and deepwater asexual, marine snails groups while exposed to the .same Lake, as well as another Lake gathered in front of the parasites, the result is a couple of interesting results. </ p> <p> First, the hybrid reproduction of marine snails groups more susceptible to infection with the parasite, which explains .the parasites and mixed groups of marine snails, so totally asexual evolution of marine snails groups against the "taste"; second, whether it be asexual reproduction of marine snails or mixed, marine snails, from other Lake parasites are fully immunized. </ p .> Only mixed reproductive group vulnerable to local parasites. <p> <wbr> </ p> <p> Experiments confirmed the hypothesis before: asexual reproduction speed advantages are, if there is no threat of parasites, the world will be asexual world; .but in common parasites in the evolution of the environment, sexual reproduction shows its advantages. </ p> In particular, as an invasive species, New Zealand, marine snails in Europe and the United States flooded. Them a year to produce 230 small snails .. The Zurich Lake in Europe, only seven years, New Zealand, marine snails of the density of up to 80 000 per square metre for specific in Europe have not met the parasite, here, all New Zealand marine snails are asexual! <p> .<wbr> </ p> <p> <wbr> </ p> <p> The Queen from the "red" to "mine-laying by the priest," two theories explained "the Red Queen," explains the origin of .<wbr> <wbr> <wbr> </ p> <p> Because a bunch of New Zealand's "Red Queen bellamya purificata," evolutionary theory became a hot topic on academics. </ p> This "Queen 's" speak very .simple, but it is the largest in the world to solve biological mysteries of a key, the mystery is: "what's the use of"? <p> <wbr> </ p> <p> 1 biology and arms race </ p .> <p> <wbr> </ p> <p> "Red Queen" (redqueen) Hansard good variety, such as "Red Queen" theory, "the Red Queen" hypothesis, "the Red Queen 's" race or " .Red Queen effect ". </ p> This word is derived from the United Kingdom mathematician, writer Lewis · Carol (LewisCarroll) of children's literature classics" Alice "Adventures in the mirror. Note, do not put this" Red Queen "and Carol's .other masterpieces of the Alice Carroll in "the Queen of hearts" and confused. The Red Queen is a chess piece, and the Queen of hearts, said of the playing cards. In the Alice mirror adventures, Alice and Red Queen in Alpine valleys running ., but it always stops in situ, sounds like "treadmill". Treadmill first appeared in 1817, was originally used to control prison sentence. 1894 this machine is starting to exercise. Don't know if it Carol. In the book, the Red .Queen said: "can you run more quickly ran more quickly, so you can stop in situ." <p> <wbr> </ p> <p> But as an important evolutionary biology, "the Red Queen's theory of" theory can .be expressed as follows: "for a living, it's evolution speed must and common evolutionary systems. </ p>" <p> <wbr> </ p> <p> Start the hypothesis to explain competition between species, "arms race" .. </ p> In 1973, the cold war was fought vying, "arms race" and the word was Chicago's evolutionary biologists van · Valentin introduces evolutionary biology. Van · Valentin is also "the Red hypotheses of the Empress", he thinks it .can explain his observed biological extinction phenomena. Van · Valentin through research, find a family survival ability of the organism does not increase over time, on the contrary, all the family the possibility of extinction of the organism is random. For example, because a .biological adaptation improvements will lead to the increase in the number of organisms, living in the same environment of other organisms will cause a lot of pressure, if you want to survive, others must make the appropriate evolution, so several bio is the world's best, .the results may further, in fact, every species survival capacity does not increase. <p> <wbr> </ p> <p> </ p> <p> Leopard and Gazelle between "arms race". </ p> < .p> <wbr> </ p> <p> The most obvious example is the predator and prey between "arms race". </ p> For example, the Cheetah must catch the Gazelle, otherwise you will starve to death. After generations .of fierce competition, ran slow Cheetah famished, survived were the elite Sprint territories. However the most goodness running Cheetah caught Gazelle but not more than their ancestors. This is because Leopard subjected to the test, the Gazelle also face the same challenge, only the .fastest Gazelle in order to survive. Although the Gazelle speed also has great progress, but can survive in Leopard claws of Gazelle will not increase, the reasoning followed in the case of a Cheetah. Leopard and Gazelle are tied to the "Red Queen" treadmills .. Both sides continued evolution, ran faster and faster, but they are things that have not ran slower than their ancestors. Leopard did not kill the vast Gazelle, Gazelle did not starve to death all the Cheetah, although they ran like the Red Queen, .but always stay. <p> <wbr> </ p> <p> 2 "Pastor" and "Queen" competition </ p> <p> <wbr> </ p> <p> Scientists </ p> Were of .the view that stronger certain sexual reproduction in the asexual. But in the origin of sexual reproduction, in the 1960s, biologists generally recognized "the pastor" Bray (Vicarof Bray) theory. <p> <wbr> </ p> <p> .Legends, United Kingdom-Bray in the 16th century there is a priest of the diocese, in order to retain teachers, according to those religious beliefs and change their beliefs. </ p> He has twice converted to Catholicism, twice converted to Protestantism. .Subsequently, this word into English idiom meaning close to "wall of grass". The theory that sexual reproduction of biological evolution faster, quicker to adapt to changes in the environment: in the asexual system, a pedigree by chance had a favorable mutations, the .mutation is not likely to spread to other families. If the family was all wiped out, beneficial mutations are erased by history; another reason is that in sexual reproduction of mating, the father and mother's genes will be exchanged, produce new genotypes. <p .> <wbr> </ p> <p> Initially, this theory by most scholars accept evolution theory. </ p> But in 1966 United States biologist Williams (GeorgeWilliams) published the adaptation and natural selection of almost sentenced to "mine-laying .by the priest to death ". Because the" theory "of the priest laying of object is a biological group, it cannot explain the sexual reproduction on organism is any good. <p> <wbr> </ p> <p> Asexual reproduction .of species, all individuals can produce offspring, and sexual reproduction of individual, only about half of the individual (female) can produce offspring, so (assuming propagation rate consistent) asexual species after the algebra will be sexual species 2N times. </ p .> This is called "of the double price", 1971, by the United Kingdom evolutionary biologists Smith (JohnSmith). The case, why can account for better sexual reproduction speed is twice the asexual biological science writer? Ridley wrote a book called the Red .Queen's law books for sexual reproduction of "Red Queen" theory widely known. <p> <wbr> </ p> <p> In fact, the "Queen" and "priests" nothing essential differences, but it changes the "environment" .is specific to the threat of parasitic organisms. </ p> Bio will produce some variation to eliminate their parasitic, and parasitic species also mutate again "upper part". The life cycle of parasites often relatively short, then came the turning quickly "Red .Queen treadmill "is enough to change slow asexual are being left behind, changes in sexual reproduction of fast can keep up with environmental change" stay ". <p> <wbr> </ p> <p>" Red Queen theory "and the ."theoretical" mines Ministers and not intrinsically contradictory, on various occasions will be instituted. </ p> In the individual scale, the "Queen" in the "species" of the scale you want to listen to "priests". <p> .<wbr> </ p> <p> 3 game promotes discussion of the "pure" </ p> <p> <wbr> </ p> <p> So, what exactly is male? all "individual", the wedding .night sex one night after their respective go baby, why not directly produce offspring of discussion "pure?", indeed, in the tiniest bacteria is similar to "sex" in Exchange, the exchange of genes behavior is finished after their respective go to split ., no discussion of the "pure". </ p> The scientists conclude that male is biological "investment strategy" results. In the course of sexual reproduction, the two sides have to mate the out half of the gene, respectively took out some .nutrients ensure baby's healthy growth. Gene of the nutrients can be ignored, so the rest of the nutrition of their respective out? this is now a requirement that only two joint ventures in order to do business, and based on objective need, at least to .investment 10000 enterprises to survive, so the number of sides? own 50% of course is the ideal, but there is always someone wants to steal the rape play slip, for example, only 49%, if both sides play slip, then Enterprise affirmative .to collapse. Last game as a result, some people have no money, anyway you can find a lot of people "joint venture"; some are out $ 10000, although you can only run an enterprise, but you can guarantee survival. The male .is a cent nor out, they produce a lot of sperm, there is no any nutrients; while the female is a $ 10 000, they generate a small amount of eggs, which contains available for child survival of nutrients. <p> <wbr .> </ p> <p> Because of the presence of parasites, that most of the biological "womanizer"; and because different investment strategies that produced a discussion of the "pure", just because of the nature and the male biological, only .insects frog song Peacock, give us a lot of fun was added. </ p> <p> <wbr> </ p> <p> New thematic interviews / reporter Liu Zheng </ p> <p> This thematic pictures are information .pictures </ p> <p> This special appreciated: </ p> <p> So Zhang Bo (College of Peking University Yuanpei) </ p> <p> Pottery Yu Ching (University) <wbr> </ p>.