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Naucni radovi zanimljivi za siru javnost


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Were our earliest ancestors from Asia?A new fossil primate from Myanmar - previously known as Burma - has led researchers to conclude that the common ancestor of humans, monkeys and apes evolved from primates in Asia, not Africa. A major focus of recent paleoanthropological research has been to establish the origin of anthropoid primates - monkeys, apes and humans - from earlier and more primitive primates known as prosimians. These include lemurs, tarsiers and their extinct relatives. The traditional view has been that anthropoids originated in Africa, but this has been challenged by recent discoveries in China, Thailand, and Myanmar. Earlier this year, the discovery of the fossil primate skeleton known as Ida in the Messel oil shale pit in Germany led some scientists to suggest that anthropoid primates evolved from lemur-like ancestors known as adapiforms. But according to Dr Chris Beard – a paleontologist at Carnegie Museum of Natural History in Pittsburgh, Pennsylvania - the new primate, Ganlea megacanina, shows that early anthropoids originated in Asia rather than Africa. These early Asian anthropoids differed radically from adapiforms like Ida, indicating that Ida is more closely related to modern lemurs than to monkeys, apes and humans. The 38-million-year-old Ganlea megacanina fossils, excavated at multiple sites in central Myanmar, belong to a new genus and species. Greatly enlarged canine teeth distinguish the animal from closely related primates, and heavy dental abrasion indicates that Ganlea megacanina used its teeth to pry open the hard exteriors of tough tropical fruits in order to extract the seeds. "This unusual type of feeding adaptation has never been documented among prosimian primates, but is characteristic of modern South American saki monkeys that inhabit the Amazon Basin," says Dr Beard. "Ganlea shows that early Asian anthropoids had already assumed the modern ecological role of modern monkeys 38 million years ago." Ganlea belongs to an extinct family of Asian anthropoid primates known as the Amphipithecidae. Two other amphipithecids were previously discovered in Myanmar, while a third was found in Thailand. A detailed analysis of their evolutionary relationships shows that amphipithecids are closely related to living anthropoids and that all of the Burmese amphipithecids evolved from a single common ancestor. Some scientists had previously argued that amphipithecids were not anthropoids at all, being more closely related to the lemur-like adapiforms. The discovery of Ganlea strongly supports the idea that amphipithecids are anthropoids, because adapiforms never evolved the features that are necessary to become specialized seed predators. Indeed, all of the Burmese amphipithecids appear to have been specialized seed predators, filling the same ecological niche occupied by modern pitheciine monkeys in the Amazon Basin of South America. During the Eocene when Ganlea and other amphipithecids were living in Myanmar, they inhabited a tropical floodplain very similar to the modern Amazon Basin.
Proceedings of the Royal Society B (Biological Sciences)Seksi teorije nisu ograničene samo na fiziku, hemiju, matematiku i druge korisne nauke...a.k.a. jesu li nacisti u stvari bili u pravu? :P
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  • 10 months later...

Imam već neko vreme utisak da ne bi bio loš ni topić gde bismo mogli da kačimo stvari koje nisu baš čudne (dakle nisu za onu drugu temu), ali su zanimljive. ...Elem, danas sam na nekom skupu upoznao ovog Inzlichta (s matične mi institucije). Evo šta jedno skoro istraživanje njegovog tima kaže:Human brain recognizes & reacts to race, UTSC researchers discover

Apr 26, 2010 by April KemickThe human brain fires differently when dealing with people outside of one’s own race, according to new research out of the University of Toronto Scarborough.This research, conducted by social neuroscientists at U of T Scarborough, explored the sensitivity of the “mirror-neuron-system” to race and ethnicity. The researchers had study participants view a series of videos while hooked up to electroencephalogram (EEG) machines. The participants – all white – watched simple videos in which men of different races picked up a glass and took a sip of water. They watched white, black, South Asian and East Asian men perform the task.Typically, when people observe others perform a simple task, their motor cortex region fires similarly to when they are performing the task themselves. However, the UofT research team, led by PhD student Jennifer Gutsell and Assistant Professor Dr. Michael Inzlicht, found that participants’ motor cortex was significantly less likely to fire when they watched the visible minority men perform the simple task. In some cases when participants watched the non-white men performing the task, their brains actually registered as little activity as when they watched a blank screen. “Previous research shows people are less likely to feel connected to people outside their own ethnic groups, and we wanted to know why,” says Gutsell. “What we found is that there is a basic difference in the way peoples’ brains react to those from other ethnic backgrounds. Observing someone of a different race produced significantly less motor-cortex activity than observing a person of one’s own race. In other words, people were less likely to mentally simulate the actions of other-race than same-race people”The trend was even more pronounced for participants who scored high on a test measuring subtle racism, says Gutsell. “The so-called mirror-neuron-system is thought to be an important building block for empathy by allowing people to ‘mirror’ other people’s actions and emotions; our research indicates that this basic building block is less reactive to people who belong to a different race than you,” says Inzlicht. However, the team says cognitive perspective taking exercises, for example, can increase empathy and understanding, thereby offering hope to reduce prejudice. Gutsell and Inzlicht are now investigating if this form of perspective-taking can have measurable effects in the brain.The team’s findings are published in the Journal of Experimental Social Psychology.

Nisam pročitao članak, nego samo ovaj prikaz, tako da ne znam da li su kontrolisali za reakcije na, recimo, ljude sa tetovažama (pitam se kakvu bi moždanu aktivnost na njih imao Yoyogi :D), napadnom šminkom, pirsinzima, roze kosom, i sličnim kerefekama. ...Već duže vreme se u slobodno vreme bavim razmišljanjem o tome kako bi rasizam i svi ostali grupizmi u stvari morali biti evolutivna prednost, te mi je milo em drago što kao svesna bića ipak možemo da odlučimo da overrideujemo automatske rasističke reakcije ako su nam ove već nametnute evolucijom (što pretpostavljam da bi mogle biti). Ako ovo i jeste evoluciona adaptacija, u društvima kao što je ovo u kome ja živim je sada jasno postala ne samo beskorisna, već verovatno i štetna.

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Mhm, ovo je rađeno sa odraslim osobama, ako sam dobro razumeo. Tu je nemoguće eleminisati već stečene predrasude. Ovakvo istraživanje bilo bi validno ukoliko bi bilo izvedeno sa malom decom.

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Strndžakali smo se s Neandertalcima i imali male anatolske neandertalčiće!! :s_w:

Neanderthals, Humans Interbred—First Solid DNA Evidence Most of us have some Neanderthal genes, study finds. Croatia's Vindija cave, where Neanderthal bones used to assemble genome were found. Image courtesy of Johannes Krause MPI-EVA.Ker Thanfor National Geographic NewsPublished May 6, 2010The next time you're tempted to call some oaf a Neanderthal, you might want to take a look in the mirror. According to a new DNA study, most humans have a little Neanderthal in them—at least 1 to 4 percent of a person's genetic makeup.The study uncovered the first solid genetic evidence that "modern" humans—or Homo sapiens—interbred with their Neanderthal neighbors, who mysteriously died out about 30,000 years ago.What's more, the Neanderthal-modern human mating apparently took place in the Middle East, shortly after modern humans had left Africa, not in Europe—as has long been suspected."We can now say that, in all probability, there was gene flow from Neanderthals to modern humans," lead study author Ed Green of the University of California, Santa Cruz, said in a prepared statement.That's no surprise to anthropologist Erik Trinkhaus, whose skeleton-based claims of Neanderthal-modern human interbreeding—previously contradicted with DNA evidence—appear to have been vindicated by the new gene study, to be published tomorrow in the journal Science."They've finally seen the light ... because it's been obvious to many us that this happened," said Trinkaus, of Washington University in St. Louis, Missouri, who wasn't part of the new study.Trinkhaus adds that most living humans probably have much more Neanderthal DNA than the new study suggests."One to 4 percent is truly a minimum," Trinkaus added. "But is it 10 percent? Twenty percent? I have no idea."(Also see "Neanderthals, Modern Humans Interbred, Bone Study Suggests.")Surprising Spot for Neanderthal-Human MatingThe genetic study team reached their conclusion after comparing the genomes of five living humans—from China, France, Papua New Guinea, southern Africa, and western Africa—against the available "rough draft" of the Neanderthal genome. (Get the basics on genetics.)The results showed that Neanderthal DNA is 99.7 percent identical to modern human DNA, versus, for example, 98.8 percent for modern humans and chimps, according to the study. (Related: "Neanderthals Had Same 'Language Gene' as Modern Humans.")In addition, all modern ethnic groups, other than Africans, carry traces of Neanderthal DNA in their genomes, the study says—which at first puzzled the scientists. Though no fossil evidence has been found for Neanderthals and modern humans coexisting in Africa, Neanderthals, like modern humans, are thought to have arisen on the continent."If you told an archaeologist that you'd found evidence of gene exchange between Neanderthals and modern humans and asked them to guess which [living] population it was found in, most would say Europeans, because there's well documented archaeological evidence that they lived side by side for several thousand years," said study team member David Reich.For another thing, Neanderthals never lived in China or Papua New Guinea, in the Pacific region of Melanesia, according to the archaeological record. (See "Neanderthals Ranged Much Farther East Than Thought.")"But the fact is that Chinese and Melanesians are as closely related to Neanderthals" as Europeans, said Reich, a population geneticist at the Broad Institute of MIT and Harvard University.(See pictures of a reconstructed Neanderthal and take a Neanderthals quiz.)Neanderthal-Human One-Night Stand?So how did modern humans with Neanderthal DNA end up in Asia and Melanesia?Neanderthals, the study team says, probably mixed with early Homo sapiens just after they'd left Africa but before Homo sapiens split into different ethnic groups and scattered around the globe.The first opportunity for interbreeding probably occurred about 60,000 years ago in Middle Eastern regions adjacent to Africa, where archaeological evidence shows the two species overlapped for a time, the team says.And it wouldn't have taken much mating to make an impact, according to study co-author Reich. The results could stem from a Neanderthal-modern human one-night stand or from thousands of interspecies assignations, he said.(Related: "Neanderthals Grew Fast, but Sexual Maturity Came Late.")More DNA Evidence for Neanderthal-Human MatingThe new study isn't alone in finding genetic hints of Homo sapiens-Homo neanderthalensis interbreeding.Genetic anthropologist Jeffrey Long, who calls the Science study "very exciting," co-authored a new, not yet published study that found DNA evidence of interbreeding between early modern humans and an "archaic human" species, though it's not clear which. He presented his team's findings at a meeting of the American Association of Physical Anthropologists in Albuquerque, New Mexico, last month.Long's team reached its conclusions after searching the genomes of hundreds of modern humans for "signatures of different evolutionary processes in DNA variation."Like the new Science paper, Long's study speculates that interbreeding occurred just after our species had left Africa, but Long's study didn't include analysis of the Neanderthal genome."At the time we started the project, I never imagined I'd ever see an empirical confirmation of it," said Long, referring to the Science team's Neanderthal-DNA evidence, "so I'm pretty happy to see it."

Ja sam 1/20 neandertalac i ponosim se svojim nasleđem. -_- Od sad stiskam report kad god se neandertalci pomenu u politički nekorektnom kontekstu.

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Strndžakali smo se s Neandertalcima i imali male anatolske neandertalčiće!! :s_w:
Originalni rad je za divno cudo besplantan na Science sajtu.No ceo taj rad se bazira na DNK materijalu iz 3 koskice nadjene u Hrvatskoj.Eeee, sumnjivo je to meni. To su mozda HR neandertalci imali bliske susrete prve vrste i mesali se sa lokalcima. A mi ostali, posebno mi iz SR, smo cist H. Sapiens. :s_w: Salu na stranu. Ali to su zaista 3 koske iz jedne jedine pecine. Postoji li neki argument za uopstavanje tih rezultata na celu populaciju? No, masta radi. Sta mislite, ko je koga tu jebavo? Dobrovoljno ili ne? Npr. nema odgovarajuce cice za zenidbu pa onda daj sta das. Ili Mara brala jagode u sumi :lol:
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Ne znam, ali reče mi jedna ovih dana da su izgleda bili inteligentniji od nas (ne znam iz kog izvora je to čula, tako da je na nivou trača). Još uvek nema ni konsenzusa o tome da li su imali jezik u našem smislu ili nisu. Vokalni trakt je u principu mogao da im podržava artikulaciju jezika sličnom jeziku H. Sapiensa. Imali su i gen koji je preliminarno doveden u vezu sa sposobnošću korišćenja hijerarhijske sintakse. I inervacija jezika (mislim jezika kao organa) im je bila na nivou naše. Jedino se ne sećam da sam igde čitao bilo šta o razvijenosti i asimetriji levog planuma temporale u odnosu na desni, što bi mogao biti jedan indikator toga da li im je mozak imao adaptacije potrebne za jezik.

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Jedino se ne sećam da sam igde čitao bilo šta o razvijenosti i asimetriji levog planuma temporale u odnosu na desni, što bi mogao biti jedan indikator toga da li im je mozak imao adaptacije potrebne za jezik.
pa kako samo na osnovu anatomije?uostalom, kao da je bitno kakva je spika, bitno je da su dri nasli 'pozitivne' rezultate. ne daj boze da neko uzme i uradi neki bootstraping ili likelihood ratio estimate na tim podacima... a i da bi hteo ne moze, na osnovu samo 3 opservacije. u svetliju politicki korektnu buducnost pod parolom: svi smo mi pomalo neandertalci (sem afrikanaca).
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Ma samo htedoh reći da je asimetrija u p.t. bitni preduslov da jezika kakav imamo u Homo sapiensu uopšte može biti. Naravno da to ne bi bio nikakav dokaz da ga je u Neandertalcima zaista i bilo. ...A meni baš kul ako jesmo po malo Neandertalci. :D

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