Divergent evolution or divergent selection is the accumulation of differences between related populations within a species, leading to speciation. Divergent evolution is exhibited when two populations become separated by a geographic barrier and experience different selective pressures that drive adaptations to their new environment. After many generations and continual evolution, the populations become unable to interbreed with one another; the American naturalist J. T. Gulick was the first to use the term "divergent evolution", with its use becoming widespread in modern evolutionary literature. Classic examples of divergence in nature are the adaptive radiation of the finches of the Galapagos or the coloration differences in populations of a species that live in different habitats such as with pocket mice and fence lizards; the term can be applied in molecular evolution, such as to proteins that derive from homologous genes. Both orthologous genes and paralogous genes can illustrate divergent evolution.
Through gene duplication, it is possible for divergent evolution to occur between two genes within a species. Similarities between species that have diverged are due to their common origin, so such similarities are homologies. In contrast, convergent evolution arises when an adaptation has arisen independently, creating analogous structures such as the wings of birds and of insects; the term divergent evolution is believed to have been first used by J. T. Gulick. Divergent evolution is defined as what occurs when two groups of the same species evolve different traits within those groups in order to accommodate for differing environmental and social pressures. Various examples of such pressures can include predation, food supplies, competition for mates; the tympanal ears of certain nocturnal insects are believed to be a result of needing the ultrasonic hearing that tympanal ears provide in order to hear predators in the dark. Non-nocturnal insects - that do not need to fear nocturnal predators - are found to lack these tympanal ears.
Animals undergo divergent evolution for a number of reasons. Predators or their absence, changes in the environment, the time at which certain animals are most active are chief among them. A lack of predators – predatory birds and mammals - for cliff-side nest residing kittiwake caused that particular group of kittiwake to lose their ancestral mobbing behavior, exhibited up until that point for protecting young; the mobbing behavior displayed by the kittiwake is lost when the kittiwake take residence in this area with little threat from predators towards their young. The mobbing behavior was developed to protect ground-level nests containing young from various predators such as reptiles and other birds; the cliff-side nesting area itself was responsible for the kittiwakes losing their mobbing mentality – predatory mammals small enough to fit on the cliff edges along with the kittiwakes and their offspring would not be able to make the climb up while predatory birds would not be able to maneuver near the cliff face while being afflicted by the weather conditions of the area.
Divergent evolution is always coupled with convergent evolution, as they are both similar and different in various facets such as whether something evolves, what evolves, why it evolves. It is instructive to compare divergent evolution with parallel evolution. Convergent evolution is defined as a similar trait evolution that occurs in two otherwise different species of animal as a result of those two species living in similar environments with similar environmental pressures like predators and food supply, it differs from divergent evolution in that the species involved are different while the traits they obtain do not differ from each other. An example of convergent evolution is the development of horns in various species for sparring over mates and territory Parallel evolution is the development of a similar trait in species descending from the same ancestor, it is similar to divergent evolution in that the species descend from the same ancestor, but it differs in that the trait is the same while in divergent evolution the trait is not.
An example of parallel evolution are certain arboreal frog species,'flying' frogs, in both Old World families and New World families having developed the ability of gliding flight. They have "enlarged hands and feet, full webbing between all fingers and toes, lateral skin flaps on the arms and legs, reduced weight per snout-vent length". One of the most famous examples of divergent evolution is the case of Darwin's Finches. During Darwin’s travels to the Galápagos Islands he discovered several different species of finch that shared a common ancestor, they had beaks that differed in shape and size reflecting their diet. The change in beak shape and size was believed to be a result of the lengths the birds had to go to in order to support their change in diet; some Galapagos finches have beaks that are more powerful to crack nuts with. A different type allows the bird to use cactus spines to spear insects in the bark of trees. Another good example of divergent evolution is the origin of the modern wolf.
Dogs and wolves both diverged from a common ancestor. To further support divergent evolution of dogs and wolves, genomic research was conducted to compare mitochondrial DNA to indicate the presence of shared ancestry. Taking 162 wolves from various parts of the world as well as 140 dogs of 60 different breeds, it is found that dogs and wolves have shared ancestry by how similar their DNA sequences are. Comparis
Diverge (2016 film)
Diverge is a 2016 American sci-fi film written, directed, co-produced and co-edited by James Morrison in his directing debut. Chris Towne is a man living in a post-apocalyptic world, desperate to find a way to save his wife from death. After meeting a strange man, he is given the chance to save the entire human race. Ivan Sandomire as Chris Towne Jamie Jackson as Leader Andrew Sensenig as Jim Eldon Erin Cunningham Anna Towne Chris Henry Coffey as Whitmore Adam David Thompson as Brad Amber Davila as Susan On review aggregator Rotten Tomatoes, the film has an approval rating of 100% based on 5 reviews, with an average rating of 7/10. Anton Bitel writing on Sight & Sound magazine included the film among the best shown on 2017 Sci-Fi-London. John Higgins from Starburst magazine gave the film 7 out of 10 stars and stated: "Sandomire is good in the lead role and holds the film together. Overall though, the smartly-written script will have the potential for repeat viewings to try and concoct where and how things unfold at the conclusion.
Like last year’s excellent "Imitation Girl", Diverge has much more to offer than CGI-action and pyrotechnics. Christopher Llewellyn Reed from "Hammer To Nail" wrote: "At 85 minutes, Diverge never overstays its welcome, proves and again, that low-budget science fiction can more than deliver."Diverge gathered awards and nominations at several festivals, including Lund International Fantastic Film Festival, Boston Science Fiction Film Festival and Julien Dubuque International Film Festival. Diverge on IMDb Diverge at Rotten Tomatoes
In mathematics, stability theory addresses the stability of solutions of differential equations and of trajectories of dynamical systems under small perturbations of initial conditions. The heat equation, for example, is a stable partial differential equation because small perturbations of initial data lead to small variations in temperature at a time as a result of the maximum principle. In partial differential equations one may measure the distances between functions using Lp norms or the sup norm, while in differential geometry one may measure the distance between spaces using the Gromov–Hausdorff distance. In dynamical systems, an orbit is called Lyapunov stable if the forward orbit of any point is in a small enough neighborhood or it stays in a small neighborhood. Various criteria have been developed to prove instability of an orbit. Under favorable circumstances, the question may be reduced to a well-studied problem involving eigenvalues of matrices. A more general method involves Lyapunov functions.
In practice, any one of a number of different stability criteria are applied. Many parts of the qualitative theory of differential equations and dynamical systems deal with asymptotic properties of solutions and the trajectories—what happens with the system after a long period of time; the simplest kind of behavior is exhibited by equilibrium points, or fixed points, by periodic orbits. If a particular orbit is well understood, it is natural to ask next whether a small change in the initial condition will lead to similar behavior. Stability theory addresses the following questions: Will a nearby orbit indefinitely stay close to a given orbit? Will it converge to the given orbit? In the former case, the orbit is called stable. An equilibrium solution f e to an autonomous system of first order ordinary differential equations is called: stable if for every ϵ > 0, there exists a δ > 0 such that every solution f having initial conditions within distance δ i.e. ‖ f − f e ‖ < δ of the equilibrium remains within distance ϵ i.e. ‖ f − f e ‖ < ϵ for all t ≥ t 0.
Asymptotically stable if it is stable and, in addition, there exists δ 0 > 0 such that whenever δ 0 > ‖ f − f e ‖ f → f e as t → ∞. Stability means; the opposite situation, where a nearby orbit is getting repelled from the given orbit, is of interest. In general, perturbing the initial state in some directions results in the trajectory asymptotically approaching the given one and in other directions to the trajectory getting away from it. There may be directions for which the behavior of the perturbed orbit is more complicated, stability theory does not give sufficient information about the dynamics. One of the key ideas in stability theory is that the qualitative behavior of an orbit under perturbations can be analyzed using the linearization of the system near the orbit. In particular, at each equilibrium of a smooth dynamical system with an n-dimensional phase space, there is a certain n×n matrix A whose eigenvalues characterize the behavior of the nearby points. More if all eigenvalues are negative real numbers or complex numbers with negative real parts the point is a stable attracting fixed point, the nearby points converge to it at an exponential rate, cf Lyapunov stability and exponential stability.
If none of the eigenvalues are purely imaginary the attracting and repelling directions are related to the eigenspaces of the matrix A with eigenvalues whose real part is negative and positive. Analogous statements are known for perturbations of more complicated orbits; the simplest kind of an orbit is an equilibrium. If a mechanical system is in a stable equilibrium state a small push will result in a localized motion, for example, small oscillations as in the case of a pendulum. In a system with damping, a stable equilibrium state is moreover asymptotically stable. On the other hand, for an unstable equilibrium, such as a ball resting on a top of a hill, certain small pushes will result in a motion with a large amplitude that may or may not converge to the original state. There are useful tests of stability for the case of a linear system. Stability of a nonlinear system can be inferred from the stability of its linearization. Let f: R → R be a continuously differentiable function with a fixed point a, f = a.
Consider the dynamical system obtained by iterating the function
Divergence is a 2005 Hong Kong action-crime film produced and directed by Benny Chan, from a screenplay by Ivy Ho. The film stars Ekin Cheng and Daniel Wu, it is about three people who cross paths after the murder of a federal witness and a kidnapping of a pop star. CID Suen Siu-yan arrests the accountant of a money launderer. However, the accountant is assassinated upon his arrival in the Hong Kong airport; the killer Coke escapes without leaving any clues. While the masterminded laundry head is happy about the soon resumption of his frozen assets for the death of his unfavorable witness, his fond son Xia is kidnapped suddenly. Suen is an ill-fated CID, he can't forget his loving girlfriend who has not yet been found. During investigation, he finds a woman who looks much alike with his missing girlfriend; the woman is the wife of the lawyer To. It raises his interest in the couple. Although the killer Coke has completed his job, he can't help feeling great interest in the case and it violates the code of killers.
He does it. And he knows; the lawyer To is successful in his field. He always helps the suspects escape from prison terms. Will there be a hidden side for an arrogant person like him? Everyone in the story seems to possess some qualities. Will it engulf them into the whirlpool? There are many other crimes around the city. Unknown motivated murders and disappearances are plentiful. Will the cases related to the 3 characters of the story? Aaron Kwok as Suen Siu-yan Ekin Cheng as To Hou-san Daniel Wu as Koo/Coke Gallen Lo as Yiu Tin-chung Angelica Lee as Siu-fong / Amy Ning Jing as Ting Eric Tsang as Uncle Choi Yu Rongguang as Inspector Mok Tommy Yuen as Yiu Ha Samuel Pang as So Fu-on Jan Lamb as Detective Chu Sam Lee as Leung Tak Lam Suet as Mou Wai-bun Divergence on IMDb Divergence at AllMovie
Divergence (Star Trek: Enterprise)
"Divergence" is the sixteenth episode of the fourth season of the American science fiction television series Star Trek: Enterprise. It aired on February 25, 2005 in the United States on UPN, it was the fourth episode of Enterprise to be written by Judith and Garfield Reeves-Stevens, was the first episode of a Star Trek series directed by David Barrett. "Divergence" is the second part of a two part story, following on from "Affliction". Set in the 22nd century, the series follows the adventures of the first Starfleet starship Enterprise, registration NX-01. In this episode, Columbia arrives so that Commander Tucker can be transferred to conduct repairs on Enterprise's warp engine before it overloads; the two ships pursue a lead to a Klingon research outpost where Phlox is under pressure to cure the virus that the Klingons created from augmented human DNA. Filming took eight days, with a two-week seasonal hiatus towards the end of December. In addition to the guest stars who appeared in "Affliction", they were joined by Wayne Grace as Admiral Krell.
The episode received Nielsen ratings of 1.7/3 percent, which were lower than the previous week's episode. The critical response was negative, directed at plot holes and characterisation. However, the two part story has been named as one of the best storylines seen in Enterprise. With the ship unable to decrease speed below warp 5, the warp core reaching dangerous levels and Commander Tucker rendezvous to provide assistance; however the crew realise that the transporter cannot be used at warp, so the ships will need to maneuver in close proximity in order for Tucker to be transferred. Captain Archer releases Lieutenant Reed from the brig to perform the transfer. Once on Enterprise, Tucker performs a rapid non-standard cold boot on the warp engine, which purges the Klingon subroutines. Meanwhile, physician Antaak and a badly beaten Doctor Phlox update General K'Vagh on their progress. K'Vagh contacts Admiral Krell, who tells him that if a cure is not completed soon, the facility will be eradicated in order to contain the disease.
Back on Enterprise, Archer questions Reed about his recent actions, is contacted by Harris from Section 31, a secretive agency within Starfleet. Harris reveals that Phlox is on an important mission and little else, but Reed reveals his location as Qu'Vat. Enterprise arrives at the colony, Archer beams down to the base with Marab to confront the Klingons and Phlox. Krell's Klingon battlecruiser and two Birds of Prey arrive in orbit and Krell orders the ships to destroy the colony. Enterprise is engaged by the Birds of Prey. Columbia arrives and joins combat with the two Birds of Prey, while Enterprise impedes the battlecruiser. Meanwhile, Phlox infects a voluntarily restrained Archer. Antaak transports a canister of the virus onto the battlecruiser which infects the crew, including Krell. Needing the cure from Phlox, Krell stands down the attack and the Klingon High Council soon agrees to distribute the cure throughout the Empire. Tucker agrees to remain onboard temporarily to assist with repairs.
Filming began on December 14, 2004 and ran for four days before the cast and crew went on a two-week break over the holiday period. The production overlapped on December 16 with second-unit filming on the episode "United", which required most of the main cast with the exception of Billingsley as Phlox; the opportunity was taken to film the majority of the sequences with Phlox, K'Vagh and Antaak at the same time on a different sound stage so as to not delay the production. After the break, production resumed on January 3, 2005. Minimal shooting was conducted on the first day for "Divergence", as further second-unit filming took place in the afternoon for "United" and for "Babel One". On the second day, Eric Pierpoint and Wayne Grace filmed their scenes as they both appeared on only one set each. Whilst filming was scheduled for seven days, the second-unit filming for "Divergence" pushed into an eighth day on January 6, which overlapped with the production of "Bound". Judith and Garfield Reeves-Stevens joined the staff as writers during season four.
Prior to "Divergence" they had written the episodes "The Forge", "Observer Effect" and "United". The Reeves-Stevens said of "Divergence", "we've written a multiple-starship action sequence that's never been seen before, that everyone's excited to bring to the screen." "Divergence" was the first Star Trek credit for director David Barrett. Several guest cast members resume their roles from "Affliction", including James Avery as K'Vagh, John Schuck as Antaak, Terrell Tilford as Marab and Eric Pierpoint as Harris, they were joined in "Divergence" by Wayne Grace as Krell. Grace had appeared across the franchise including in a voice role in the computer game Star Trek: Klingon Academy, a Cardassian in the Star Trek: Deep Space Nine episode "Wrongs Darker Than Death or Night" and as the Klingon Governor Torak in Star Trek: The Next Generation's "Aquiel". Kristin Bauer made her franchise debut as Laneth, she became better known in her appearances as Pam in HBO's True Blood. "Divergence" aired on UPN, on February 25, 2005.
According to Nielsen Media Research, the episode received a 1.7/3 percent share. This means that it was seen by 1.7 percent of the population, 3 percent of all viewers watching television at the time of the broadcast. This was less than the ratings received by the previous episode, "Affliction", which scored ratings of 1.8/3 percent. It finished behind programs on NBC, ABC, CBS and Fox as well as What I Like About You and a repeat of Reba during the second half-hour on The WB. Michelle
Divergent is the debut novel of American novelist Veronica Roth, published by Harper Collins Children's Books in 2011. The novel is the first of the Divergent trilogy, a series of young adult dystopian novels set in a Divergent Universe; the novel Divergent features a post-apocalyptic version of Chicago and follows Beatrice "Tris" Prior as she explores her identity within a society that defines its citizens by their social and personality-related affiliation with five factions, which removes the threat of anyone exercising independent will and re-threatening the population's safety. Underlying the action and dystopian focused main plot is a romantic subplot between Tris and one of her instructors in the Dauntless faction, nicknamed Four; the novel has been compared to other young adult books such as The Hunger Games and The Maze Runner because of its similar themes and target audience. In particular, the novel explores the themes common to young adult fiction, such as adult authority and the transition from childhood to maturity, as well as such broader motifs as the place of violence and social structures within a post-apocalyptic society.
Its major plot device, the division of society into personality types, is one used in other science fiction works. Beyond its literary context, Roth's open declaration of her religion as a Christian has brought commentary from Christian communities both endorsing and challenging the novel. Roth wrote Divergent while working on a Creative Writing degree at Northwestern University, it was purchased for publication alongside the subsequent books in the trilogy. Summit Entertainment purchased the media rights to the book in 2011 and subsequently produced a film adaptation titled Divergent, released March 21, 2014; the film, a success amongst audiences, generated $288,747,895 at the box office despite mixed reviews from critics. The novel is Veronica Roth's debut novel and was published a little over a year after Roth graduated with a Bachelor's degree from the Creative Writing program at Northwestern University. Roth wrote the novel during her senior year winter break and sold movie rights to the novel before she graduated.
She had been working on the series from Four's point of view but decided that he was not the character she wanted for her series. Four years she decided to pick up the novel from a different point of view. Roth wrote the series from Beatrice's point of view. Tris was the right character. Four still remained in the series and we find more deep secrets about him; the novel is set in a post-apocalyptic Chicago. Roth indicated that she did not intend to use Chicago as the setting: I wrote the rough draft and I felt like it needed a more grounded sense of place, I looked at the city I had described, all these trains moving, this lake marsh, these rivers, and I realized that it was Chicago and it was just because that's the city I've known and loved the longest. In post-apocalyptic Chicago, survivors are divided into five factions: the selfless. All sixteen-year-olds are tested to determine which faction they are best suited for, but select their own faction at the Choosing Ceremony; those who do not complete initiation become "factionless,” living on the streets.
Sixteen-year-old Beatrice Prior feels. Her inconclusive test results mark her as “Divergent,” and the test administrator Tori warns her never to tell anyone. Agonizing over her future, Beatrice decides to join Dauntless, her brother Caleb chooses Erudite. The new Dauntless initiates jump onto a moving train to Dauntless headquarters, are instructed to jump onto the roof. Most make it, they are ordered to jump into the compound entrance. Reaching the bottom, she tells the instructor Four. Four explains that, unlike the other factions, who accept all successful initiates, only the top ten Dauntless initiates will stay while the rest become Factionless. Tris comes into conflict with others. In the first stage of initiation, they are trained in guns and hand-to-hand combat. Despite her lack of physical strength, Tris finishes in sixth place. A relationship emerges between Tris and Four, Tris is pummeled by Peter in a fight. After the Stage 1 rankings are announced, the second-place Peter stabs first-place Edward in the eye.
Edward leaves to become Factionless, followed by his girlfriend Myra. On Visiting Day, Tris learns that her mother was Dauntless. Erudite stirs dissent against the city's Abnegation leadership and accuses their leader Marcus of abusing his son; the rumors are fueled by the fact that Marcus' son, as well as Tris and Caleb, all left Abnegation, alleged to be hoarding supplies. The initiates enter Stage 2. Tris' Divergent abilities earn her the top rank. Peter, Al attack Tris, threatening sexual assault and nearly throwing her to her death, but Four intervenes. Al begs Tris' forgiveness; the final stage gathers the initiates’ fears into a simulated “fear landscape,” testing their acquired skills. Tris and Four grow closer, he lets her into his own fear landscape, she learns he is Marcus' son Tobias, the claims of abuse were true. Four uncovers Erudite's plans to use Dauntless to stage an attack on Abnegation. Tris overcomes her fear landscape, the Dauntless initiates are injec
The divergence problem is an anomaly from the field of dendroclimatology, the study of past climate through observations of old trees the properties of their annual growth rings. It is the disagreement between the temperatures measured by the thermometers and the temperatures reconstructed from the latewood densities or, in some cases, widths of tree rings in the far northern forests. While the thermometer records indicate a substantial late 20th century warming trend, many tree rings from such sites do not display a corresponding change in their maximum latewood density. In some studies this issue has been found with tree ring width. A temperature trend extracted from tree rings alone would not show any substantial warming since the 1950s; the temperature graphs calculated in these two ways thus "diverge" from one another, the origin of the term. The problem of changing response of some tree ring proxies to recent climate changes was identified in Alaska by Taubes 1995 and Jacoby & d'Arrigo 1995.
Tree ring specialist Keith Briffa's February 1998 study showed that this problem was more widespread at high northern latitudes, warned that it had to be taken into account to avoid overestimating past temperatures. The deviation of some tree ring proxy measurements from the instrumental record since the 1950s raises the question of the reliability of tree ring proxies in the period before the instrumental temperature record; the wide geographic and temporal distribution of well-preserved trees, the solid physical and biological basis for their use, their annual discrimination make dendrochronology important in pre-instrumental climate reconstructions. Tree ring proxies are consistent with other proxy measurements for the period 1600–1950. Before around AD 1600, the uncertainty of temperature reconstructions rises due to the relative paucity of data sets and their limited geographic distribution; as of 2006, these uncertainties were considered too great to allow conclusion on whether the tree ring record diverges from other proxies during this period.
In more recent studies evidence suggested that the divergence is caused by human activities, so confined to the recent past, but use of affected proxies can lead to overestimation of past temperatures, understating the current warming trend. The explanation for the divergence problem is still unclear, but is to represent the impact of some other climatic variable, important to modern northern hemisphere forests but not significant before the 1950s. Rosanne D'Arrigo, senior research scientist at the Tree Ring Lab at Columbia University's Lamont-Doherty Earth Observatory, hypothesises that "beyond a certain threshold level of temperature the trees may become more stressed physiologically if moisture availability does not increase at the same time." Signs suggestive of such stress are visible from space, where satellite pictures show "evidence of browning in some northern vegetation despite recent warming." Other possible explanations include that the response to recent rapid global warming might be delayed or nonlinear in some fashion.
The divergence might represent changes to other climatic variables to which tree rings are sensitive, such as delayed snowmelt and changes in seasonality. Growth rates could depend more on annual maximum or minimum temperatures in temperature limited growth regions. Another possible explanation is global dimming due to atmospheric aerosols. In 2012, Brienen et al. proposed that the divergence problem was an artefact of sampling large living trees. Taubes, G. "Is a Warmer Climate Wilting the Forests of the North?", Science, 267: 1595, Bibcode:1995Sci...267.1595T, doi:10.1126/science.267.5204.1595, PMID 17808119. Jacoby, G. C.. "Tree ring width and density evidence of climatic and potential forest change in Alaska", Global Biogeochemical Cycles, 9: 227, Bibcode:1995GBioC...9..227J, doi:10.1029/95GB00321, The recent increase in temperatures combined with drier years may be changing the tree response to climate. Briffa, Keith R.. "Reduced sensitivity of recent tree-growth to temperature at high northern latitudes", Nature, 391: 678, Bibcode:1998Natur.391..678B, doi:10.1038/35596.
Curiosity Rises With Trees' Strange Growth Spurt, NPR, March 28, 2010