| 单词 | speciation |
| 例句 | What impetus drove the descent of, say, thirteen variants of finches down the fierce rivulets of speciation? The Gene 2016-06-02T00:00:00Z The separation of the speakers by migrations had effects on language comparable to the speciation observed by Darwin on various islands of Galapagos. The Lives of a Cell 1974-01-01T00:00:00Z The Christian concept of speciation placed God firmly at the epicenter; all animals created by Him sprayed outward from the moment of creation. The Gene 2016-06-02T00:00:00Z This mechanism of speciation was not just conjecture; Dobzhansky could demonstrate it experimentally. The Gene 2016-06-02T00:00:00Z "Because of the rate at which it mutates, we were able to demonstrate why DXZ4 is probably linked to speciation," Murphy said. New secrets about cat evolution revealed 2023-11-02T04:00:00Z But a study of fossils from East Africa’s Lake Victoria shows that it takes more than arriving early to win the speciation race. Study of 17,000 years of fish fossils reveals rapid evolution 2023-10-04T04:00:00Z The strength of Darwin's finches as a study organism lies in what they can show about the early stages of speciation. Genome study reveals 30 years of Darwin's finch evolution 2023-09-29T04:00:00Z PlantServation also enabled the scientists to experimentally replicate what happens after the natural speciation of a hybrid polyploid species. AI increases precision in plant observation 2023-09-22T04:00:00Z Additionally, scientists have found that the further the distance between two groups that once were the same species, the more likely it is that speciation will occur. Fundamentals of Biology 2015-01-01T00:00:00Z Through their research, Murphy and his colleagues now better understand which parts of cat DNA cause those variations, especially the variations that define speciation, or the differences between species. New secrets about cat evolution revealed 2023-11-02T04:00:00Z The greater age provides more time for speciation. Concepts of Biology 2013-04-25T00:00:00Z Sympatric speciation does not require a geographic barrier and explains how many different species can inhabit the same area. Biology for AP Courses 2022-06-09T00:00:00Z Over thousands or millions of years, rapid bursts of speciation can occur. Miller & Levine Biology 2018-01-01T00:00:00Z In the gradual speciation example, a founder species of bird diverges into one species with a hooked beak, and another with strait beak. Fundamentals of Biology 2015-01-01T00:00:00Z Likewise, the reverse is true when extinction rates begin to overtake speciation rates. Environmental Biology 2018-09-06T00:00:00Z The complexity of tropical ecosystems may promote speciation by increasing the habitat heterogeneity, or number of ecological niches, in the tropics relative to higher latitudes. Concepts of Biology 2013-04-25T00:00:00Z One form of sympatric speciation begins with a serious chromosomal error during cell division. Biology for AP Courses 2022-06-09T00:00:00Z Because of a lack of competition, evolution and speciation can occur relatively rapidly. Miller & Levine Biology 2018-01-01T00:00:00Z Gradual speciation is most likely to occur in species that live in a stable climate. Fundamentals of Biology 2015-01-01T00:00:00Z The greater age provides more time for speciation, the evolutionary process of creating new species. Environmental Biology 2018-09-06T00:00:00Z When speciation rates begin to outstrip extinction rates, the number of species will increase; likewise, the reverse is true when extinction rates begin to overtake speciation rates. Concepts of Biology 2013-04-25T00:00:00Z This type of speciation is more common in plants than in animals, though some examples in animals exist. Biology for AP Courses 2022-06-09T00:00:00Z Since Darwin’s original ideas, technology has provided many tools and mechanisms to study how evolution and speciation take place and this arsenal of tools is growing. An Introduction to Geology 2017-01-01T00:00:00Z Gradual speciation and punctuated equilibrium both result in the divergence of species. Fundamentals of Biology 2015-01-01T00:00:00Z The complexity of tropical ecosystems may promote speciation by increasing the habitat complexity, thus providing more ecological niches. Environmental Biology 2018-09-06T00:00:00Z For speciation to occur, two new populations must be formed from one original population, and they must evolve in such a way that it becomes impossible for individuals from the two new populations to interbreed. Concepts of Biology 2013-04-25T00:00:00Z In fact, the presence in nature of hybrids between similar species suggests that they may have descended from a single interbreeding species, and the speciation process may not yet be complete. Biology for AP Courses 2022-06-09T00:00:00Z Since their introduction, the red and black fire ants have hybridized into a new ant, unique to North America, that shows signs of speciation. Invasive fire ants could be controlled by viruses, scientists say 2022-06-17T04:00:00Z Visit this website to continue the speciation story of the snails. Fundamentals of Biology 2015-01-01T00:00:00Z The stability of tropical ecosystems might promote speciation. Environmental Biology 2018-09-06T00:00:00Z Sympatric speciation, meaning speciation in the “same homeland,” involves speciation occurring within a parent species while remaining in one location. Concepts of Biology 2013-04-25T00:00:00Z Given the extraordinary diversity of life on the planet there must be mechanisms for speciation: the formation of two species from one original species. Biology for AP Courses 2022-06-09T00:00:00Z A third study found that the U.K.’s feeding of Blackcaps could be driving a speciation event between birds that leave for continental Europe and ones who stay around feeders in the winter. Bird Feeders Are Good for Some Species—But Possibly Bad for Others 2022-03-04T05:00:00Z Late in the Cenozoic, further extinctions followed by speciation occurred during ice ages that covered high latitudes with ice and then retreated, leaving new open spaces for colonization. Fundamentals of Biology 2015-01-01T00:00:00Z The number of species on the planet, or in any geographical area, is the result of an equilibrium of two evolutionary processes that are ongoing: speciation and extinction. Environmental Biology 2018-09-06T00:00:00Z These variances can lead to evolved differences in the owls, and over time speciation will likely occur unless gene flow between the populations is restored. Concepts of Biology 2013-04-25T00:00:00Z For speciation to occur, two new populations must be formed from one original population and they must evolve in such a way that it becomes impossible for individuals from the two new populations to interbreed. Biology for AP Courses 2022-06-09T00:00:00Z The students suggested these factors: natural selection, morphological mutations, punctuated equilibrium and allopatric speciation. Perspective | New Jersey’s governor blocked the growth of its best charter schools. Why? 2022-02-20T05:00:00Z Figure 11 shows this type of speciation among a cichlid fish population in Nicaragua. Fundamentals of Biology 2015-01-01T00:00:00Z When speciation rates begin to outstrip extinction rates, the number of species will increase. Environmental Biology 2018-09-06T00:00:00Z Over time, the varied demands of their new lifestyles lead to multiple speciation events originating from a single species, which is called adaptive radiation. Concepts of Biology 2013-04-25T00:00:00Z Biologists think of speciation events as the splitting of one ancestral species into two descendant species. Biology for AP Courses 2022-06-09T00:00:00Z The result, in the first half of the book, is a dense but lucid guide to the history and biology of speciation on Earth. Review | Timeless meditations on Earth’s fragility, and the damage humans do 2021-05-12T04:00:00Z In the punctuated equilibrium example, as in the graduated speciation example, the founder species diverges into one species with a hooked break and another with a straight beak. Fundamentals of Biology 2015-01-01T00:00:00Z “This study is one of surprisingly few that compellingly document sympatric speciation caught in the act” in vertebrates, says Martha Muñoz, an evolutionary biologist at Yale University who was not involved with the work. Tiny differences in plumage and song have split two nearly identical birds into different species 2021-03-25T04:00:00Z One form of sympatric speciation can begin with a chromosomal error during meiosis or the formation of a hybrid individual with too many chromosomes. Concepts of Biology 2013-04-25T00:00:00Z Researchers have found hundreds of sympatric speciation events in these fish, which have not only happened in great number, but also over a short period of time. Biology for AP Courses 2022-06-09T00:00:00Z Island living tends to encourage speciation—or the divergence of one species into two or more lineages. This country is where you can find some of the world’s rarest animals 2021-01-28T05:00:00Z In fact, the presence in nature of hybrids between similar species suggests that they may have descended from a single interbreeding species, and the speciation process may not yet be completed. Fundamentals of Biology 2015-01-01T00:00:00Z But other researchers say the research appears to show how sympatric speciation happens—and in this case, happened so quickly. Tiny differences in plumage and song have split two nearly identical birds into different species 2021-03-25T04:00:00Z One leads to allopatric speciation, whereas the other leads to sympatric speciation. Concepts of Biology 2013-04-25T00:00:00Z Nevertheless, two populations with distinct morphologies and diets now exist in the lake, and scientists believe these populations may be in an early stage of speciation. Biology for AP Courses 2022-06-09T00:00:00Z At other times, extinction crises cut back life on Earth, and speciation did not immediately follow. Earth’s Biodiversity Bursts Do Not Follow Expected Pattern 2021-01-14T05:00:00Z Think of them as the happy little shrubs of speciation. Why Some Tropical Fish Are Gettin’ Squiggly With It 2020-08-22T04:00:00Z The findings allowed them to estimate speciation rates, and how fast new species spread from one region to others. Many beloved garden flowers originated in this mountain hot spot—the oldest of its kind on Earth 2020-07-30T04:00:00Z The second is that speciation occurs by splits of one species into two, never more than two at a time, and essentially at one point in time. Concepts of Biology 2013-04-25T00:00:00Z In terms of how quickly speciation occurs, two patterns are currently observed: gradual speciation model and punctuated equilibrium model. Biology for AP Courses 2022-06-09T00:00:00Z The oak genome is thus a mosaic shaped by speciation and hybridization. How Oak Trees Evolved to Rule the Forests of the Northern Hemisphere 2020-07-14T04:00:00Z The Himalaya straddles seven nations and has a unique ecosystem of mountain peaks that act like isolated islands to drive speciation. Daily briefing: Why protests haven’t lead to a surge in COVID-19 2020-06-23T04:00:00Z Plant speciation accelerated again about 15 million years ago, when geologic evidence indicates monsoons intensified, reshaping the landscape. Many beloved garden flowers originated in this mountain hot spot—the oldest of its kind on Earth 2020-07-30T04:00:00Z In fact, the presence of hybrids between similar species suggests that they may have descended from a single interbreeding species and that the speciation process may not yet be completed. Concepts of Biology 2013-04-25T00:00:00Z In the gradual speciation model, species diverge gradually over time in small steps. Biology for AP Courses 2022-06-09T00:00:00Z Rather adaptive radiation led to higher speciation rates in these evolutionarily young Mexican oaks as they moved into the mountains. How Oak Trees Evolved to Rule the Forests of the Northern Hemisphere 2020-07-14T04:00:00Z The slope of the curve fitted to such a plot, often denoted by λ, is the net speciation rate. Evolutionary trees can’t reveal speciation and extinction rates 2020-04-14T04:00:00Z Using these phylogenies, they were able to estimate colonization, extinction and speciation rates. Biodiversity theory backed by island bird data 2020-02-18T05:00:00Z Allopatric speciation, meaning speciation in “other homelands,” involves a geographic separation of populations from a parent species and subsequent evolution. Concepts of Biology 2013-04-25T00:00:00Z In the case of gradual speciation, the fossil record would show only a few hybrid individuals, followed by individuals of the two distinct species. Biology for AP Courses 2022-06-09T00:00:00Z The discovery suggests a genetic mechanism for creating barriers to reproduction between populations of a species, which promotes speciation. Solving the Mystery of Songbird Diversity 2019-11-07T05:00:00Z The number of species in the present depends on how speciation and extinction rates varied over time in the past. Evolutionary trees can’t reveal speciation and extinction rates 2020-04-14T04:00:00Z And as water froze into glaciers, sea levels dropped, isolating shallow seas and creating niches for speciation. Veil of dust from ancient asteroid breakup may have cooled Earth 2019-09-18T04:00:00Z Finally, a well-documented example of ongoing sympatric speciation occurred in the apple maggot fly, Rhagoletis pomonella, which arose as an isolated population sometime after the introduction of the apple into North America. Concepts of Biology 2013-04-25T00:00:00Z In the case of gradual speciation, the fossil record would show the parent species in a single location, such that the newly diverged species remained in contact with each other. Biology for AP Courses 2022-06-09T00:00:00Z The findings prompted the authors to suggest that more complex mechanisms than temperature or ecological opportunity were the main drivers of passerine speciation. Solving the Mystery of Songbird Diversity 2019-11-07T05:00:00Z The slope of the curve equals the speciation rate minus the extinction rate. Evolutionary trees can’t reveal speciation and extinction rates 2020-04-14T04:00:00Z Finally, speciation refers to branching, when one species bifurcates into two different species. Winston Churchill’s Thoughts on Evolution 2019-09-16T04:00:00Z It seems likely that host specificity of parasites in general is a common cause of sympatric speciation. Concepts of Biology 2013-04-25T00:00:00Z The production of unfit hybrids would increase and the speciation process would complete. Biology for AP Courses 2022-06-09T00:00:00Z "We wanted to explore anole lizards to study the evolution of gene regulation, since they've experienced a series of speciation events on Caribbean islands, much like Darwin's finches of the Galapagos." The first gene-edited lizard walks among us 2019-09-04T04:00:00Z We have become the major driver of extinction and also, probably, of speciation. Louisiana’s Disappearing Coast 2019-03-25T04:00:00Z This revealed a conclusive link: historically high temperatures and carbon dioxide levels both increased the rates of mosquito speciation. Mosquito-borne diseases get a boost from climate change 2019-03-30T04:00:00Z However, if two rodent populations became divided by the formation of a new lake, continued gene flow would be unlikely; therefore, speciation would be more likely. Concepts of Biology 2013-04-25T00:00:00Z The gene pools of the parent species would fuse over time, reversing the speciation process. Biology for AP Courses 2022-06-09T00:00:00Z The same stunning geography that gave rise to such unparalleled speciation has left people isolated in remote villages, far from any clinic. A prescription for Madagascar’s broken health system: data and a focus on details 2019-02-28T05:00:00Z Crick implied that science would solve the mind-body problem by investigating the physiological underpinnings of mental phenomena, just as it solved problems like speciation, heredity and metabolism. Why the Mind–Body Problem Can't Have a Single, Objective Solution 2018-10-06T04:00:00Z "All the variation required for speciation is already there" in the hybrids. Ancient hookups between different species may explain Lake Victoria’s stunning diversity of fish 2018-08-09T04:00:00Z Additionally, scientists have found that the further the distance between two groups that once were the same species, the more likely for speciation to take place. Concepts of Biology 2013-04-25T00:00:00Z Aside from geographic isolation leading to reproductive isolation, predict two other mechanisms of speciation in a population and how these mechanisms can lead to a scientific definition of a subspecies. Biology for AP Courses 2022-06-09T00:00:00Z Indeed, evolutionary biologists no longer need to travel to remote places like the Galápagos to discover their holy grail: speciation, the formation of new and distinct species in the course of evolution. Darwin comes to town: how cities are creating new species 2018-07-23T04:00:00Z Most taxonomic groups are made up of lineages with both low and high speciation rates. Speciation far from the madding crowd 2018-07-03T04:00:00Z “I’m sure we will find speciation on even smaller islands.” How much space do you need to evolve a new mammal? These worm-eating mice have the answer 2018-05-15T04:00:00Z Sympatric speciation may also take place in ways other than polyploidy. Concepts of Biology 2013-04-25T00:00:00Z Restricted gene flow, on the other hand, can lead to abrupt differences, even speciation. Biology for AP Courses 2022-06-09T00:00:00Z All this research seems to point in one direction: that the urban blackbird is evolving into a separate species, a case of true speciation. Darwin comes to town: how cities are creating new species 2018-07-23T04:00:00Z The marine fishes in the authors’ large phylogenetic trees were no exception, with speciation rates varying by more than 50-fold between lineages. Speciation far from the madding crowd 2018-07-03T04:00:00Z Instead, Dr. Janke said, at least some of the whale speciation has been driven by personal taste. Baleen Whales Intermingled as They Evolved, and Share DNA With Distant Cousins 2018-04-04T04:00:00Z Figure 11.19 shows this type of speciation among a cichlid fish population in Nicaragua. Concepts of Biology 2013-04-25T00:00:00Z Evaluate Carson’s reasoning for speciation and ongoing evolution. Biology for AP Courses 2022-06-09T00:00:00Z In the new view, instead of a hatchet strike, speciation is a fraying tapestry whose threads might weave back together. Ravens mated another species into oblivion, their twisted family tree shows 2018-03-02T05:00:00Z The authors combined these values with global maps of where these species live, revealing a clear geographical structure to the speciation rates. Speciation far from the madding crowd 2018-07-03T04:00:00Z But the issue remains contentious: Hybridization has been definitively shown to cause widespread speciation only in plants. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z Sympatric speciation can occur through errors in meiosis that form gametes with extra chromosomes, called polyploidy. Concepts of Biology 2013-04-25T00:00:00Z The process of speciation within the same space is called sympatric speciation; the prefix “sym” means same, so “sympatric” means “same homeland” in contrast to “allopatric” meaning “other homeland.” Biology for AP Courses 2022-06-09T00:00:00Z But hybridisation and speciation is happening quickly, too. Books of the Year 2017 2017-12-07T05:00:00Z But whether the authors considered the patterns looking species by species, place by place or ecoregion by ecoregion, there was always a pattern of the average speciation rate increasing from the tropics towards the poles. Speciation far from the madding crowd 2018-07-03T04:00:00Z Charles Darwin believed that speciation probably took place over hundreds if not thousands of generations, advancing far too gradually to be detected directly. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z Two species of fish had recently undergone sympatric speciation. Concepts of Biology 2013-04-25T00:00:00Z A number of mechanisms for sympatric speciation have been proposed and studied. Biology for AP Courses 2022-06-09T00:00:00Z Indrė Žliobaitė and colleagues modelled speciation and extinction using a random walk constrained by resources and uncovered a unimodal 'hat' pattern. Reconciling taxon senescence with the Red Queen’s hypothesis 2017-11-28T05:00:00Z This negative result suggests that a high-latitude marine environment, rather than the species that colonizes it, drives high speciation rates. Speciation far from the madding crowd 2018-07-03T04:00:00Z The breakneck pace of that speciation event turned heads both in the scientific community and in the media. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z So hybridisation can lead to speciation, simply through the addition of one individual to a population. Bird caught in act of becoming new species 2017-11-23T05:00:00Z If this group of fish continued to remain separate from the first population, eventually sympatric speciation might occur as more genetic differences accumulated between them. Biology for AP Courses 2022-06-09T00:00:00Z Perhaps the title should have something to do with allopatric speciation as well as just the numbers of the pigeons. A Population of Billions May Have Contributed to This Bird’s Extinction 2017-11-16T05:00:00Z The correlation of high speciation rates with low diversity is consistent with the idea that there are unfilled ecological opportunities near the poles. Speciation far from the madding crowd 2018-07-03T04:00:00Z On Daphne, the conditions may have been just right for hybrid speciation. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z By identifying one way that new species can arise, and following the entire population, the researchers state this as an example of speciation occurring in a timescale we can observe. Bird caught in act of becoming new species 2017-11-23T05:00:00Z One such place is Lake Victoria in Africa, famous for its sympatric speciation of cichlid fish. Biology for AP Courses 2022-06-09T00:00:00Z "Once we get rid of the orb web, that's where we see some of the biggest bursts of speciation," Bond says. Spider genes put a new spin on arachnids’ potent venoms, stunning silks, and surprising history 2017-10-19T04:00:00Z Writing in Nature, Rabosky et al.4 document a speciation rate for marine fishes at high latitudes that is twice the speciation rate in tropical seas. Speciation far from the madding crowd 2018-07-03T04:00:00Z “Conditions on the islands really help drive the speciation process,” said Scott Edwards, an ornithologist at Harvard University. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z This is the first example of speciation that scientists have been able to observe directly in the field. Bird caught in act of becoming new species 2017-11-23T05:00:00Z Figure 18.23 shows this type of speciation among a cichlid fish population in Nicaragua. Biology for AP Courses 2022-06-09T00:00:00Z And the idea of the potential of a child — that spoke to me of a moment of speciation and that opened up themes that were very interesting and avenues of story. 'Blade Runner 2049' writers Hampton Fancher and Michael Green on whether Deckard is a replicant and other mysteries 2017-10-09T04:00:00Z There are two potential drivers of high speciation rates in the tropics. Speciation far from the madding crowd 2018-07-03T04:00:00Z Some experts think that even today hybrid speciation may be far from rare. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z Researchers followed the entire population of finches on a tiny Galapagos island called Daphne Major, for many years, and so they were able to watch the speciation in progress. Bird caught in act of becoming new species 2017-11-23T05:00:00Z The primary influencing factor on changes in speciation rate is environmental change. Biology for AP Courses 2022-06-09T00:00:00Z Each internode of the gene tree was then defined as either a duplication node, a speciation node, or a ‘dubious’ node. The Apostasia genome and the evolution of orchids : Nature : Nature Research 2017-09-12T04:00:00Z These dated trees enable speciation rates to be inferred on the basis of the branching patterns of the tree. Speciation far from the madding crowd 2018-07-03T04:00:00Z But very fast hybrid speciation events like the one the Grants saw on Daphne may often occur in bursts — only to end with the new species dying out before we have time to observe it. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z "It's an extreme case of something we're coming to realise more generally over the years. Evolution in general can happen very quickly," said Prof Roger Butlin, a speciation expert who wasn't involved in the study. Bird caught in act of becoming new species 2017-11-23T05:00:00Z If the hybrids are less fit than the parents, reinforcement of speciation occurs, and the species continue to diverge until they can no longer mate and produce viable offspring. Biology for AP Courses 2022-06-09T00:00:00Z The idea that today’s decimation is qualitatively different to the mass extinctions of yore, and that a compensating mass speciation is already under way, seems at some level to be quite encouraging. The coming sixth extinction 2017-08-03T04:00:00Z One way such speciation might happen is when two geographically separate populations that are derived from a single species meet. How species originate 2017-07-27T04:00:00Z By contrast, speciation isn’t likely to occur this way in less isolated regions, said Trevor Price, an ecologist at the University of Chicago. When two different types of birds mated, a new species, Big Bird, was born 2018-01-05T05:00:00Z Prof Butlin told the BBC that people working on speciation credit the Grant professors with altering our understanding of rapid evolutionary change in the field. Bird caught in act of becoming new species 2017-11-23T05:00:00Z This term is used because the low success of the hybrids reinforces the original speciation. Biology for AP Courses 2022-06-09T00:00:00Z Consequently, instead of globalisation resulting in prosperity and freedom for all, it might actually result in speciation: the divergence of humankind into different biological castes or even different species. Are we about to witness the most unequal societies in history? 2017-05-24T04:00:00Z The fast-growing mountains also created microclimates at different elevations, sparking speciation and funneling new plants and animals into the Amazon basin. Was the Amazon once an ocean? 2017-05-03T04:00:00Z The much older speciation of the two P. ovale parasites and the fact that they have been considered identical until recently shows the limitation of morphology alone in species determination. Plasmodium malariae and P. ovale genomes provide insights into malaria parasite evolution : Nature : Nature Research 2017-01-24T05:00:00Z The chimp-bonobo results help "us to understand the nature of speciation," says A. Rus Hoelzel, an evolutionary biologist at Durham University in the United Kingdom. Chimps and bonobos had flings—and swapped genes—in the past 2016-10-27T04:00:00Z As their ideas take shape and as research reveals new details about how life evolves, they develop models to help explain rates of speciation. Biology for AP Courses 2022-06-09T00:00:00Z But still, on each of the Channel Islands the foxes were undergoing the long, slow process of speciation. On Santa Cruz Island, they killed the cows, sheep, and bees. Now it’s time to finish the job 2016-08-25T04:00:00Z "The reason this system is so interesting is that it's a smoking gun for speciation," he explained. With no males, these butterflies are evolving into separate species 2016-07-20T04:00:00Z Bull and his co-author, Martine Maron of the University of Queensland, identify four main forces of speciation — relocation, domestication, hunting and novel ecosystem creation — and offer examples of each. Humans are driving the evolution of new species — and that could be just as bad as causing extinctions 2016-06-29T04:00:00Z "This process very well might be an engine of speciation," Pitnick said. Fruit fly sperm is epically long, and we may finally know why 2016-05-25T04:00:00Z The primary influencing factor on changes in speciation rate is environmental conditions. Biology for AP Courses 2022-06-09T00:00:00Z “That would provide a fast route to speciation.” Animal behaviour: Come mate with me : Nature : Nature Publishing Group 2015-10-06T04:00:00Z There were a lot of reasons that trying to create a one-stop, go-to destination for all research on speciation was an audacious idea. A Wikipedia for New Species (No Unicorns, Please) 2015-09-21T04:00:00Z Generally, new species arise gradually over long periods of time, but the genetic studies indicate that in this case speciation was virtually instantaneous, something that happens in plants but is very rare in animals. Crayfish create a new species of female 'superclones' 2015-08-26T04:00:00Z Indeed, in lineages that have pollinia, the speciation rate was 5.1% higher than in lineages that don’t, Givnish and colleagues report this week in the Proceedings of the Royal Society B. Orchids’ dazzling diversity explained 2015-08-25T04:00:00Z Without genetic variation, speciation would not be possible. Biology for AP Courses 2022-06-09T00:00:00Z If paleontologists want to study trends of speciation and diversification during the Mesozoic, they usually look to the records of dinosaurs and mammals to describe evolutionary trends. Dramatic Cretaceous Greenhouse Conditions Allowed Turtles To Inch Towards Higher Latitudes 2015-08-03T04:00:00Z Pitted against selective pressures is an equally extraordinary process of creation, diversification, speciation, and radiation. Can Ya Dig It?—How Rebels, Hipsters and Mr. (and Ms.) Cool Reshaped Consumer Culture [Excerpt] 2015-05-08T04:00:00Z In reality, speciation is almost always precisely the opposite: it’s slow, takes place in a population, and requires the accumulation of many discrete genetic differences, none of which are particularly dramatic. An Evolution Outreach: How Species Evolve Like Languages 2014-12-14T05:00:00Z The rate of speciation among these cloud forest dwellers rose 24.9% compared with lineages that stayed in the lowlands. Orchids’ dazzling diversity explained 2015-08-25T04:00:00Z Genetic variation influences sympatric speciation, but not allopatric speciation. Biology for AP Courses 2022-06-09T00:00:00Z However, again, none of these criteria require that speciation will ultimately occur. There Is No Such Thing as Race The right side of the graph, representing larger islands, displays a steeper slope, because speciation here is the dominant factor. Lizard Stowaways Revise Principle of Ecology 2014-10-20T04:00:00Z “Different families will go in different shape trajectories than another family. It is like speciation,” Chitwood says. Plant Biology Informs the Origins of the Stradivarius 2014-10-10T04:00:00Z Gravendeel thinks that this deceit probably did accelerate speciation, but that researchers have either misidentified or missed anatomical details in many tropical orchids. Orchids’ dazzling diversity explained 2015-08-25T04:00:00Z Which is least likely to be a factor that increases the probability of speciation by adaptive radiation? Biology for AP Courses 2022-06-09T00:00:00Z Since speciation develops very slowly, it is useful to recognize intermediate stages in this process. There Is No Such Thing as Race But later versions began to include speciation, which depends on an island’s size rather than its isolation. Lizard Stowaways Revise Principle of Ecology 2014-10-20T04:00:00Z Most importantly, it laid the theoretical foundations for a quantitative and rigorous understanding of adaptation and speciation, two of the most fundamental evolutionary processes. Does evolutionary theory need a rethink? 2014-10-07T04:00:00Z Cichlid fish adaptive radiation is characterized by rapid speciation without geographical isolation. The genomic substrate for adaptive radiation in African cichlid fish : Nature : Nature Publishing Group 2014-09-02T04:00:00Z Graudal speciation and punctuated equilibrium both result in the divergence of species. Biology for AP Courses 2022-06-09T00:00:00Z They would be in various stages of the process of speciation but not yet different species. There Is No Such Thing as Race Historically, speciation boosted the number of species more quickly than migration did, hence the steeper slope. Lizard Stowaways Revise Principle of Ecology 2014-10-20T04:00:00Z Importantly, they demonstrate that development is a direct cause of why and how adaptation and speciation occur, and of the rates and patterns of evolutionary change. Does evolutionary theory need a rethink? 2014-10-07T04:00:00Z The radiations in Lake Victoria and Malawi thus display the highest sustained rates of speciation known to date in vertebrates7. The genomic substrate for adaptive radiation in African cichlid fish : Nature : Nature Publishing Group 2014-09-02T04:00:00Z In the gradual speciation model, traits change incrementally. Biology for AP Courses 2022-06-09T00:00:00Z “People went overboard with interpreting islands of speciation,” Hahn said. Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z The pre-penultimate paragraph about prevailing racial views influencing the hard science around speciation is fascinating. Should You Fear the Pizzly Bear? 2014-08-14T04:00:00Z Changes in the hereditary material are an essential part of adaptation and speciation. Does evolutionary theory need a rethink? 2014-10-07T04:00:00Z Taken together, these results suggest that even the most recent rapid speciation in African lake cichlids is associated with genomically widespread divergence. The genomic substrate for adaptive radiation in African cichlid fish : Nature : Nature Publishing Group 2014-09-02T04:00:00Z Genetic variation would decrease and speciation would be possible. Biology for AP Courses 2022-06-09T00:00:00Z Taken together, the research is beginning to create a picture of the process of speciation. Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z When scientists warn of the danger posed by hybridization, this is what they mean: speciation in reverse, the loss of biodiversity. Should You Fear the Pizzly Bear? 2014-08-14T04:00:00Z These genes, found on chromosome 3 in Eucalyptus, are part of a syntenic set of genes found on Populus chromosome XVIII, indicating that these genes pre-date the speciation events that separate these genera. The genome of Eucalyptus grandis : Nature : Nature Publishing Group 2014-06-10T04:00:00Z These data suggest contrasting genomic mechanisms underlying phenotypic evolution depending on whether speciation is driven primarily by divergence of coloration and associated traits or by divergence of morphology associated with feeding ecology. The genomic substrate for adaptive radiation in African cichlid fish : Nature : Nature Publishing Group 2014-09-02T04:00:00Z Genetic variation would decrease and speciation would not be possible. Biology for AP Courses 2022-06-09T00:00:00Z This uncertainty highlights one of the challenges of studying speciation. Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z The pre-penultimate paragraph about prevailing racial views influencing the hard science around speciation is fascinating. Should You Fear the Pizzly Bear? 2014-08-14T04:00:00Z Future studies of variation in functional genes will provide insights into the relative influences of drift and selection on Eucalyptus evolution and identify mechanisms of speciation and adaptive divergence. The genome of Eucalyptus grandis : Nature : Nature Publishing Group 2014-06-10T04:00:00Z I started the day's lesson ... one on speciation, but that wasn't enough for them. Variations : Nature : Nature Publishing Group 2014-05-27T04:00:00Z Sympatric speciation is more common because it prevents gene flow between the species. Biology for AP Courses 2022-06-09T00:00:00Z “When you do start to diverge, what types of genes diverge first? Which genes drive speciation? What are the first things that become differentiated?” Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z “Long after speciation, even nonsister species can actually exchange genes, some of which are useful,” James Mallet, an evolutionary biologist at Harvard, told me. Should You Fear the Pizzly Bear? 2014-08-14T04:00:00Z Eucalyptus may thus provide a model for the evolution of responses to divergent sets of flowering cues required for wide colonization and speciation. The genome of Eucalyptus grandis : Nature : Nature Publishing Group 2014-06-10T04:00:00Z “People believe that there must be a speciation gene,” Andolfatto says. No Single Gene Responsible for Animal Domestication 2014-05-13T04:00:00Z What pattern in the fossil record would you expect to see to support the model of gradual speciation? Biology for AP Courses 2022-06-09T00:00:00Z The more interesting and important question, biologists say, is what drives two populations to diverge, a process known as speciation. Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z Nearly a decade ago, after a drought, the Grants began to see speciation in real time. Should You Fear the Pizzly Bear? 2014-08-14T04:00:00Z The fly Philornis downsi represents a serious threat to the iconic birds, whose speciation patterns were key to Charles Darwin's theory of evolution. Darwin's Finches Stamp Out Deadly Parasite with Help from Cotton Balls 2014-05-06T15:30:00Z Generalizations about rates of molecular evolution, and what they imply about speciation, derived from such a limited sample may be premature. [Technical Response] Response to Comment on “The Placental Mammal Ancestor and the Post–K-Pg Radiation of Placentals” 2013-08-08T17:55:23.633Z In the case of gradual speciation, the fossil record would show many intermediate forms. Biology for AP Courses 2022-06-09T00:00:00Z Then that region expands, and new islands harboring other divergent genes emerge, creating islands of speciation across the genome. Baffling Genetic Barrier Prevents Similar Animals from Interbreeding 2014-08-21T04:00:00Z The formation of the islands of Borneo and Sumatra resulted in the speciation of the two corresponding orangutan populations. Great ape genetic diversity and population history 2013-07-24T17:21:11.837Z "Scientists have studied speciation … for many years, and this opens up a whole new aspect to it." Gut Microbes Can Split a Species 2013-07-18T19:00:00Z Their wide geographic dispersal mitigates against speciation and extinction. [Technical Response] Response to Comments on “Can We Name Earth’s Species Before They Go Extinct?” 2013-07-18T17:55:35.987Z Gradual speciation would be undetectable in the fossil record. Biology for AP Courses 2022-06-09T00:00:00Z “It’s a way of having instant speciation,” she says. Long-lived insects raise prime riddle 2013-05-29T17:20:23.740Z This model presents a complete overview of great ape divergence and speciation events in the context of historical effective population sizes. Great ape genetic diversity and population history 2013-07-24T17:21:11.837Z For in plants, unlike animals, polyploidy is common, seemingly innocuous, and often acted upon by natural selection as an instrument of speciation. For Plants, Polyploidy Is Not a Four-Letter Word 2013-05-19T23:45:00.497Z So, we have to think in terms of sympatric speciation when considering the species recognition hypothesis. Dinosaurs and their exaggerated structures : species recognition aids, or sexual display devices? 2013-04-22T01:15:00.783Z Because this work is framed by the central organizing principle of evolution it is possible to forget that there are people living today who need evidence that speciation and extinction have occurred throughout Earth’s history. Biology for AP Courses 2022-06-09T00:00:00Z But Amemiya adds that, for now, the role of non-coding DNA in speciation is “speculative”, and its significance in coelacanth evolution is not clear. ‘Living fossil’ genome unlocked 2013-04-17T17:20:38.200Z The formation of the islands of Borneo and Sumatra resulted in the speciation of the two corresponding orangutan populations. Great ape genetic diversity and population history 2013-07-24T17:21:11.837Z Today scientists look at Timema’s DNA to study how different forms of coloring or camouflage affect speciation. Getting the Big Picture: BMC Ecology Image Competition Winners [Slide Show] 2013-03-25T19:45:00.523Z Geographic isolation and speciation were prominent on those hot, sweaty and incredibly diverse land masses. Darwin Day: A personal offering 2013-02-13T00:15:00.270Z Describe conditions that lead to speciation in terms of the accumulation of many small genetic changes where very sharp differences in oxygen availability were geographically imposed. Biology for AP Courses 2022-06-09T00:00:00Z What's more, he says ecologists could find many more examples of sympatric speciation by studying the numerous localities around the world with similarly sharp ecological boundaries. Blind Mole Rats Show Evolution in Action 2013-01-28T20:00:00Z Similar actions are suggested for other speciation genes. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z The understanding of past domestication, including the selections on critical traits and the recent rapid speciation, will further guide future breeding efforts. A map of rice genome variation reveals the origin of cultivated rice 2012-10-24T17:21:24.910Z The story of any speciation event—the point when a species branches into two—can reveal the importance of genetic changes and how they relate to functional changes in biochemistry or behavior. See Change: Rapid Emergence of New Sea Star Species Illustrates Evolution's Power 2012-08-10T15:45:02.653Z We have learned that evolution and speciation continue to occur, but Earth has experienced five mass extinctions—the elimination of major groups of species. Biology for AP Courses 2022-06-09T00:00:00Z Sergey Gavrilets, an evolutionary biologist at the University of Tennessee, Knoxville, is more comfortable with the idea that the mole rats may be undergoing speciation. Blind Mole Rats Show Evolution in Action 2013-01-28T20:00:00Z However, more than 150years after the publication of On the Origin of Species, the genetic basis of speciation is still largely unresolved. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z I don't remember the details, but I questioned his argument that speciation is an entirely gradual process. Turning point: Alison Galvani 2012-07-11T17:20:50.577Z Finding out exactly which changes led to this speciation event is tricky. See Change: Rapid Emergence of New Sea Star Species Illustrates Evolution's Power 2012-08-10T15:45:02.653Z The idea is that greater age provides more time for speciation. Biology for AP Courses 2022-06-09T00:00:00Z That said, Gavrilets agrees with Nevo that sharp ecological boundaries may be "especially promising" locations to search for examples of sympatric speciation -- examples that could settle the controversy about how common the process really is. Blind Mole Rats Show Evolution in Action 2013-01-28T20:00:00Z Unravelling the genomic landscape of divergence between lineages is key to understanding speciation. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z As a result of its dual role in mimicry and mate selection, divergence in wing pattern is also associated with speciation and adaptive radiation. Butterfly genome reveals promiscuous exchange of mimicry adaptations among species 2012-07-04T17:21:31.773Z As surprising as the sea stars may be, evolutionary theory does predict such rapid speciation, Coyne says. See Change: Rapid Emergence of New Sea Star Species Illustrates Evolution's Power 2012-08-10T15:45:02.653Z The complexity of tropical ecosystems may promote speciation by increasing the heterogeneity, or number of ecological niches, in the tropics relative to higher latitudes. Biology for AP Courses 2022-06-09T00:00:00Z Exactly how often this so-called sympatric speciation occurs in nature remains a topic of hot debate. Blind Mole Rats Show Evolution in Action 2013-01-28T20:00:00Z This study provides a roadmap to the emerging field of speciation genomics. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z Simulations of a neutral model indicate, however, that isolated assemblages under various configurations of random speciation and extinction do sustain strong correlations in the diversity of shared families. [Technical Comment] Comment on “Global Correlations in Tropical Tree Species Richness and Abundance Reject Neutrality” 2012-06-28T18:25:17.810Z Following this speciation event, bonobos and chimpanzees then split from their common ancestor approximately 1.5 million years ago. The Better Bonobos of Our Nature 2012-06-19T23:15:04.947Z However, this hypothesis suffers from some circularity—ecosystems with more species encourage speciation, but how did they get more species to begin with? Biology for AP Courses 2022-06-09T00:00:00Z "Sympatric speciation could be more common than we think," he says. Blind Mole Rats Show Evolution in Action 2013-01-28T20:00:00Z Revealing the genomic regions with elevated levels of divergence will eventually deepen our knowledge of the speciation process. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z The Distant Future: Speciation and the Evolution of Homo extraterrestrialis When will we see even more fundamental biological change–speciation? Migration from Earth: Human Evolution and Space Colonization 2012-06-15T20:15:00.223Z As do the proponents of the evolutionary species concepts, I believe that species are real, are individuals and ancestral species do not need to become extinct during a speciation event. Species Concepts 2012-04-20T14:15:03.823Z The tropics have their own forms of seasonality, such as rainfall, but they are generally assumed to be more stable environments and this stability might promote speciation. Biology for AP Courses 2022-06-09T00:00:00Z In addition, the genome-wide set of divergent regions already provides new insights into evolutionary processes shaping adaptive evolution and ecological speciation. The genomic basis of adaptive evolution in threespine sticklebacks 2012-04-04T17:21:30.320Z The naturally hybridizing collared flycatcher and pied flycatcher are important avian speciation models that show pre- as well as postzygotic isolation. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z The largest subgroup of the family, Rafflesia, which includes three foot wide blood-red flowers, experienced a rapid and recent burst of speciation within the last 1-2 million years. Visiting the corpse plant 2012-03-21T19:15:00.247Z Linking evolutionary pattern and process: the relevance of species concepts for the study of speciation. Species Concepts 2012-04-20T14:15:03.823Z When speciation rates begin to outstrip extinction rates, the number of species will increase; likewise, the number of species will decrease when extinction rates begin to overtake speciation rates. Biology for AP Courses 2022-06-09T00:00:00Z Horizontal lines indicate speciation times within the hominine subfamily and the sequence divergence time between human and orang-utan. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z To conclude, this study presents the genome sequence of an avian speciation model and unravels the genomic landscape of species divergence in unprecedented detail. The genomic landscape of species divergence in Ficedula flycatchers 2012-12-05T15:23:01.900Z “Mayr believed, in most cases, speciation involved movement of a few individuals into an isolated area, followed by a genetic revolution,” said Theodore Garland, an evolutionary biologist at the University of California, Riverside. Castaway lizards put evolution to the test 2012-02-05T00:22:56Z Thus, it can only consider barriers to fertilization as modes of speciation. Species Concepts 2012-04-20T14:15:03.823Z The fundamental conclusion was that biodiversity on an island was a function of the origin of species through migration, speciation, and extinction on that island. Biology for AP Courses 2022-06-09T00:00:00Z Below are mean nucleotide divergences between human and the other great apes from the EPO alignment. b, Great ape speciation and divergence times. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z They are generally regarded as periods of warmth and aridity and, therefore, probably are times of segmentation of the ranges of boreal mammals and hence times exceptionally favorable to the process of speciation. Speciation of the Wandering Shrew 2011-12-22T03:00:30.143Z The occurrence of any physical or biotic barrier that would have separated this homogeneous group would be conducive to speciation. Speciation and Evolution of the Pygmy Mice, Genus Baiomys 2011-12-15T03:00:11.933Z The stem species, by definition, ceases to exist by way of either extinction of speciation. Species Concepts 2012-04-20T14:15:03.823Z Smaller islands are also less geographically diverse so there are fewer niches to promote speciation. Biology for AP Courses 2022-06-09T00:00:00Z The grey shaded region shows that an increase in mutation rate going back in time can accommodate present-day estimates, fossil hypotheses, and a middle Miocene speciation for orang-utan. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Glacial ages, characterized by extensive and continuous areas of boreal habitat, probably were times of relatively unrestricted gene flow between many populations of boreal mammals and hence not favorable to rapid speciation. Speciation of the Wandering Shrew 2011-12-22T03:00:30.143Z The outcome of speciation will ultimately depend on the degree of contact between lineages, which appear greatly accelerated by people. The Biogeography of Rats and Their Quest for Global Domination 2011-11-09T23:15:02.907Z Boeke says that when more of the yeast genome is synthesized, researchers will be able to use the system to study evolution and speciation. Yeast Thrives with Partially Synthetic Genome 2011-09-14T21:45:03.587Z However, if speciation has occurred, even when brought back together, they will retain their species identity. Biology for AP Courses 2022-06-09T00:00:00Z We discuss these and other constraints on estimates of great ape speciation times in the . Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z In addition: Boeke says that when more of the yeast genome is synthesized, researchers will be able to use the system to study evolution and speciation. Yeast Goes Synthetic 2011-09-14T20:17:36Z Nonetheless, it is worth looking at some of the film’s errors about evolution and speciation because they may be reinforcing some popular misconceptions. The Evolutionary Errors of X-Men 2011-06-03T19:15:02.187Z But the fossil record of placental mammals is reliable and does not record a speciation until later. As Dinosaurs Waned and Mammals Rose, the Lowly Louse Kept Pace 2011-04-06T20:07:46Z Scientists have documented numerous cases of allopatric speciation taking place. Biology for AP Courses 2022-06-09T00:00:00Z Under conditions of genetic exchange between populations after the main separation of the chimpanzee and human lineages, the speciation time estimated by CoalHMM represents an average weighted by gene flow over the period of separation. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Some of our work is revealing that geographic differences in plumage, like eye ring presence, absence or shape, function as species recognition signals and may play a role in speciation. Scientist at Work: Answering Questions About Island Species 2011-02-25T12:05:50Z Dubbed “the speciation gene”, if ’s two roles turn out to be linked, it could be evolution’s missing X factor. The Human Genome at Ten 2011-02-15T15:31:51Z Their molecular clock data suggest a much earlier speciation, perhaps prompted by the breakup of the ancient supercontinent of Gondwana around 120 million years ago. As Dinosaurs Waned and Mammals Rose, the Lowly Louse Kept Pace 2011-04-06T20:07:46Z Additionally, scientists have found that the farther the distance between two groups that once were the same species, the more likely it is that speciation will occur. Biology for AP Courses 2022-06-09T00:00:00Z However it would only be more recent than the speciation time inferred from fossils if there had been strong gene flow between populations after the development of derived fossil characteristics. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Thus eye ring differences among white-eyes may drive reproductive isolation, and ultimately speciation, among island bird populations. Scientist at Work: Answering Questions About Island Species 2011-02-25T12:05:50Z For a recent example, see how the hypothesis of butterfly migration and speciation by Nabokov was said to have been confirmed by a recent molecular study. Circadian clock without DNA--History and the power of metaphor 2011-02-11T16:15:02.303Z They detected signals of ecological speciation in all three species, including the clear divergence in color phenotype, but also in body shape and size. Editors' Choice 2011-01-20T19:25:02.033Z These variances can lead to evolved differences in the owls, and speciation likely will occur. Biology for AP Courses 2022-06-09T00:00:00Z We propose a synthesis of genetic and fossil evidence consistent with placing the human–chimpanzee and human–chimpanzee–gorilla speciation events at approximately 6 and 10 million years ago. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z These tissues enable the genetic analyses that have so profoundly altered our ability to analyze speciation history and relationships among island populations. Scientist at Work: Answering Questions About Island Species 2011-02-25T12:05:50Z Glor believes his work with Rabosky represents the "final word" on the importance of limits on species diversity over the rate of speciation when explaining the species-area relationship in anole lizards. Research Shows That Environmental Factors Limit Species Diversity 2010-12-22T16:07:00Z Phenotypical adaptations to local environmental variation were observed in all species, but thus far, only H. maculata showed evidence of true ecological speciation. Editors' Choice 2011-01-20T19:25:02.033Z Over time, the varied demands of their new lifestyles lead to multiple speciation events originating from a single species. Biology for AP Courses 2022-06-09T00:00:00Z Horizontal lines indicate speciation times within the hominine subfamily and the sequence divergence time between human and orang-utan. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z The easy explanation for the incredible diversification is that as the Rocky Mountains emerged millions of years ago, multiple, isolated deserts formed, leaving ample opportunity for speciation to occur. Observatory: A Reason for Diversity of Ants May Not Hold 2010-08-16T23:39:00Z “Drowned islands downstream from the Galapagos hotspot imply extended speciation times.” 2010-02-02T23:33:00Z Biological exploration of M�xico and Central America has revealed the presence of a diverse fauna, elements of which have undergone speciation in separate areas within the relatively small region. Descriptions of New Hylid Frogs From Mexico and Central America One form of sympatric speciation can begin with a serious chromosomal error during cell division. Biology for AP Courses 2022-06-09T00:00:00Z Below are mean nucleotide divergences between human and the other great apes from the EPO alignment. b, Great ape speciation and divergence times. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Dr. Pitts and his colleagues are now expanding their study of velvet ant speciation to Central and South America. Observatory: A Reason for Diversity of Ants May Not Hold 2010-08-16T23:39:00Z Mammals of the Mesquite Plains Biotic District in Texas and Oklahoma, and speciation in the central grasslands. Geographic Variation in the Harvest Mouse, Reithrodontomys megalotis, On the Central Great Plains And in Adjacent Regions A hybrid woodpecker and its significance in speciation in the genus Dendrocopos. Birds from Coahuila, Mexico Without genetic variation, speciation would occur more slowly. Biology for AP Courses 2022-06-09T00:00:00Z The grey shaded region shows that an increase in mutation rate going back in time can accommodate present-day estimates, fossil hypotheses, and a middle Miocene speciation for orang-utan. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z It is a special kind of sympatric speciation. Biology for AP Courses 2022-06-09T00:00:00Z Allopatric speciation is more common because it prevents gene flow between the species. Biology for AP Courses 2022-06-09T00:00:00Z Allopatric speciation is more common because it involves stronger prezygotic barriers. Biology for AP Courses 2022-06-09T00:00:00Z There is no relationship between genetic variation and any form of speciation. Biology for AP Courses 2022-06-09T00:00:00Z To the extent that this is plausible, for example as part of a non-allopatric speciation process, it constitutes an alternative explanation for the dating discrepancy without requiring a change in mutation rate. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Sympatric speciation is more common because it involves stronger prezygotic barriers. Biology for AP Courses 2022-06-09T00:00:00Z A phylogenetic tree is not related to the passing of time because speciation is based on geographic changes. Biology for AP Courses 2022-06-09T00:00:00Z When a fly or flies arrived on a newer island, speciation occurred, which, after a time, stabilized until another island hop occurred. Biology for AP Courses 2022-06-09T00:00:00Z Which situation would most likely lead to allopatric speciation? Biology for AP Courses 2022-06-09T00:00:00Z In summary, although whole-genome comparisons can be strongly conclusive about the ordering of speciation events, the inability to observe past mutation rates means that the timing of events from genetic data remains uncertain. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z This variation reflects local differences in the ancestral effective population size Ne during the period between the gorilla and chimpanzee speciation events, most probably due to natural selection reducing and making ILS less likely. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z Our calculation of α assumes that a single speciation time applies across the genome, attributing differences between the X chromosome and autosomes to the factors mentioned above. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z An alternative model has been proposed, involving complex speciation, with more recent human–chimpanzee ancestry on X than elsewhere. Insights into hominid evolution from the gorilla genome sequence 2012-03-07T18:21:00.777Z |
| 随便看 |
|
英语例句辞典收录了117811条英语例句在线翻译词条，基本涵盖了全部常用单词及词组的例句翻译及用法，是英语学习的有利工具。