The positions of two alleged human ancestors in the family tree is becoming clearer, or murkier, depending on whom you ask. This illustrates the uncertainty and disparity of opinions in this field.Hobbit workshop: Regarding the diminutive skeletons dubbed Homo floresiensis found in Indonesia, opinions seems to be condensing around the idea they were true Homo sapiens, not missing links. Bruce Bower reported in Science News (162:22:141, June 3), summarizing a paper by Adam Brumm et al. in Nature last week,1 that stone tools found elsewhere on the island of Flores appear to match those in the Liang Bua cave where H. floresiensis was discovered. But these artifacts are dated at up to 840,000 years old, whereas the bones of Hobbit Man are thought to be much more recent (estimated 74,000 to 12,000 years), within the time frame when true Homo sapiens are believed to have inhabited the island. This raises several questions:Can we trust the dates? Bower quotes James L. Phillips (Field Museum, Chicago) calling the idea “beyond belief” that the tools at the other site are connected culturally with H. floresiensis. He says, “Mata Menge artifacts lay in unstable river sediment that moved over time, making it impossible to obtain accurate age estimates, Phillips holds.”Can we measure brain power from bones? The stone toolwork, apparently unique to Flores, displays humanlike technology. “The latest Flores finds show that the diminutive islanders, with their craniums the size of chimps’, possessed enough brainpower to parlay cultural traditions into effective toolmaking,” Bowers writes.Can we know the toolmakers? Though 3,626 artifacts have been excavated in the cave hideout of Hobbit man, “I don’t think we can rule out Homo sapiens as the [maker] of the Liang Bua tools,” John Shea (State U of New York) said.Can we assume cross-cultural connections? According to Bower, Dietrich Stout (University College, London) remarked that “It’s hard to know whether a single Stone Age culture connected residents of Mata Menge to Liang Bua’s inhabitants or whether separate hominid populations happened to exploit similar, basic toolmaking techniques.”Indeed, it appears hard to know anything at all about this population. Since the dates of H. floresiensis are too recent to consider them missing links or derivatives of Homo erectus, a minority of scientists still contend the specimens are examples of modern humans with microcephalic disorder (see Science 19 May, 2006). An article on BBC News mentions the puzzle of the hundreds of thousands of years alleged between Mata Menge and Liang Bua; “We can’t guarantee that this material really is related because of the large time gap,” Chris Stringer of the Natural History Museum, UK, commented.Neanderthal genes: European scientists reporting in Current Biology2 sequenced another strand of Neanderthal DNA in hopes of shedding light on whether Neanderthals and modern humans interbred (see 05/22/2006). In short, they reported that there is still a distinction between the DNA of the two groups, but that Neanderthal genetic diversity has been underestimated, and is comparable to modern human genetic diversity. They could not discern if the diversity was due to cohabitation, climactic changes, or subdivisions of populations; “Thus, more Neandertal sequences than the six presently available and longer than 100 bp [base-pairs] are needed to fully understand the extent of the past diversity of Neandertals.”No firm conclusions here, either, but that has not stopped Steven Mithen (U. of Reading, UK) from writing a whole book speculating that Neanderthals were the first musicians (see Reuters story on MSNBC.com). The storytelling goes on: “It was a dark and stormy night, and in a cave in what is now southern France, Neanderthals were singing, dancing and tapping on stalagmites with their fingernails to pass the time.”1Adam Brumm et al., “Early stone technology on Flores and its implications for Homo floresiensis,” Nature 441, 624-628 (1 June 2006) | doi:10.1038/nature04618.2Orlando et al., “Revisiting Neandertal diversity with a 100,000 year old mtDNA sequence,” Current Biology, Volume 16, Issue 11, June 2006, pages R400-R402, doi:10.1016/j.cub.2006.05.019.The MSNBC story about Neanderthal music continues by asking whether such a cave concert might have actually happened, or is a figment of Mithen’s imagination. The answer is: the latter. In neither story are data definitive enough to draw conclusions. In the case of Hobbit man, they cannot be sure which tools are associated with which population, who is related to whom, how old they are, how long they were there, and what their capabilities were. It seems incredible to expect a simple stone-tool technology to persist on one island for over 800,000 years without change. And making inferences about intelligence based on brain size is fraught with fallacies; consider how capable a hummingbird is with a brain the size of a grain of rice (see next story). None of these reports contradict the creationist position that humans have always been humans and had their intellectual and artistic abilities from day one, or shall we say, Day Six. According to the Bible, Adam’s great grandchildren were already accomplished farmers, metallurgists and musicians (see Genesis 4), having invented these skills from scratch using their God-given abilities, without hundreds of thousands of years of mutations and natural selection. Do you need a model that fits the evidence? Put this score on your music stand and play it. (More harmony, less cacophony.)(Visited 16 times, 1 visits today)FacebookTwitterPinterestSave分享0
(Visited 40 times, 1 visits today)FacebookTwitterPinterestSave分享0 With the resurrection of Brontosaurus as a valid dinosaur name after a century of repudiation, what’s a kid to think? Thoughts on science’s arbitrary and tentative nature.Eight-year-olds used to brag about correcting their parents who said “Brontosaurus.” The correct name is “Apatosaurus,” the kid would be quick to say. Now the parent has a comeback: Brontosaurus is a valid name for some of the members of the Diplodocidae, according to a new reclassification of the giant sauropods by a team led by Emanuel Tschopp from Nova University of Lisbon, according to Nature. His team studied all the known fossils of the beasts and concluded that Edward Cope’s name Brontosaurus (“thunder lizard”) is valid, because there are enough distinguishable traits to distinguish it from Othniel Marsh’s earlier find that he had named Apatosaurus (“deceptive lizard”).Tschopp says he did not start out to resurrect Brontosaurus, but his team’s analysis decided enough differences warranted the reversal. “The Smithsonian Institution accused USPS of favoring ‘cartoon nomenclature to scientific nomenclature,’” Michael Balter writes in Science Magazine. “It didn’t help that the stamps were officially launched at Disney World.” The cartoonists may have the last laugh. Undoubtedly some parents will enjoy rubbing it in to their kids: “See? I was right!” dad will say. “We were both right!” may be the retort.Old dinosaur hunter Bob Bakker welcomes the change, because it gives him new evolutionary themes to work on: “this group of critters, the long-neck Apatosaurs, evolved faster than we’ve been giving them credit for,” he said in Live Science. Did you hear the one about Brontosaurus being really an Apatosaurus with the wrong head? That’s a “popular myth,” says the BBC News.According to the new names, “thunder lizard” and “deceptive lizard” are distinct genera. But maybe both names are wrong; these dinosaurs are not lizards at all. Lizards have legs splayed out to the side, and dinosaurs have them underneath. But then “dinosaur” means “terrible lizard.” Will there be terrible thunder at this deceptive naming scheme that depends on ‘saurus’ (lizard)? What’s in a name, anyway?Obviously the dinosaurs didn’t call themselves Bronto- or Apato-saurus. They just lived and ate and fought. It’s humans that are obsessed with pigeonholing things into classification schemes. The lumpers want more items in bigger bins; the splitters want fewer items in smaller bins. The “bone wars” between Marsh and Cope in the 19th century track the classification wars of taxonomists. It cannot be ruled out that some future day a taxonomist will want to lump the diplodocids into bigger bins. Maybe he or she will keep Bronto and ditch the “deceptive lizard” Apato, leading future kids to tell the parents, “The correct name is Brontosaurus.” The bones won’t have changed; just the human scheme.This is a take-home lesson about scientific hubris, Balter concludes:Some paleontologists have reservations. “It’s going to force us to ask questions about what we really mean by genus and species in a paleontological context,” says paleontologist John Whitlock of Mount Aloysius College in Cresson, Pennsylvania. “Is it more useful to distinguish specimens as Brontosaurus and Apatosaurus than it is to distinguish A. excelsus from other species of Apatosaurus? I don’t know, but I hope it’s the start of a conversation.” He and others, including Tschopp himself, note that the characters used aren’t cut-and-dried and could be scored differently by others.Upchurch thinks this kind of detailed taxonomy could help resolve questions such as how diverse dinosaurs were just before they went extinct about 66 million years ago. Others welcome the resurrection of an icon. “Brontosaurus has a prominent place in the public imagination,” Mannion says. “It can only be a good thing that it is back with us. … It shows that science develops through time and that it’s possible to change our minds, even about long-held views.”Would it be possible to change long-held views about subjects like evolution or global warming? Think about all the recent overconfidence by climatologists about anthropogenic climate change, resulting in global conferences determined to force draconian measures on nation’s economies. News flash! This just in! Quirin Schiermeier writes in Nature,Climate science needs more mathematicians and physicists. So say prominent climatologists who are trying to spark enthusiasm for their field in budding researchers who might otherwise choose astrophysics or cosmology. Talented physical scientists are needed to help resolve mysteries that are crucial to modelling the climate — and, potentially, saving the planet — the group says, such as the ways in which clouds are formed.There is a misconception that the major challenges in physical climate science are settled. “That’s absolutely not true,” says Sandrine Bony, a climate researcher at the Laboratory of Dynamic Meteorology in Paris. “In fact, essential physical aspects of climate change are poorly understood.”With that kind of thunder in the clouds, maybe climate science will have its Brontosaurus moment. The article doesn’t doubt anthropogenic climate change, but if “essential physical aspects” that feed the models are “poorly understood,” and the models generate all the media hype, what’s an observant layman to think? “The perception that climate science is ‘solved’ is an inadvertent result of pressure on climatologists to convey a simple message to the public,” one climate modeler stated. Another added, “We too quickly turn to the policy implications of our work and forget the basic science.”Scientific nomenclature can be matters of economic viability. Is the “delta smelt” an “endangered species”? There’s no question its numbers are down, but how diverse is it from other species of smelt? National Geographic talks about the little fish that is at the heart of California’s “water wars”. Massive efforts to save this fish have destroyed farms and left millions of acres of land fallow for years, due to policy decisions to cut water delivery in the central valley to save the fish instead of people’s livelihoods. Scientific nomenclature can also be matters of life and death. Is it useful to call depression a mental illness? And how definitive is the label “depression”? Does it help to add the adjective “clinical” in front of it? In the wake of co-pilot Andreas Lubitz’s “conscious decision” to commit murder-suicide in a Germanwings aircraft, killing 154 people, Peter Kinderman of the University of Liverpool argues in Live Science that the labels have no explanatory value. “Individuals commit murder-suicide, not the ‘mentally ill’,” his headline reads. Instead of applying labels, he advises, we should be on the lookout for combinations of traits and actions that put people at risk for heinous deeds.These are just a few recent examples of revisions that undermine science’s claim to progress in the knowledge of truth. Zacharias Maniadas thinks that economic theory can help science’s ‘credibility problem’. “Science is considered a source of truth and the importance of its role in shaping modern society cannot be overstated,” he says in The Conversation. “But in recent years science has entered a crisis of trust.” He advises that “implementing the transparency proposals will help science fulfil [sic] its purpose of discovering the truth.” But the transparency proposals are built on models; what if essential aspects of those models are also poorly understood? After all, human nature is much more complex than the way clouds are formed. The old question comes up again: who watches the watchers?Science becomes much more fun when you see the blowhards as cartoon characters. Real scientists are humble. Always be wary, because despite the thunder in the media, deceptive lizards are not extinct.
The textbook theory of the first migration to the Americas across a land bridge is “dead in the water.”Early people were smarter than anthropologists thought. They didn’t wait till the ice melted to cross the Bering Sea by a land bridge, as textbooks have taught for decades. They made canoes and boats and traveled along the coast. And why did they discover America? Because it was there. They had a spirit of exploration, just like many people do today.That’s the new story coming from Eske Willerslev and colleagues, publishing in Nature. Ewen Callaway, writing in the same issue of Nature, explains how new evidence from cores along the assumed land-bridge route show the area was uninhabitable when the first migrants were thought to avail themselves of a route to America. “It’s 1,500 kilometres,” says co-author David Meltzer. “You can’t pack a lunch and do it in a day.” Willerslev believes these people had some common sense, according to Live Science‘s coverage:The first Americans were clearly curious explorers, but they were also realists, Willerslev said.“We are talking [932 miles] 1,500 kilometers you have to pass with ice caps on each side. It’s not like, ‘Oh yeah, I’m just taking a three-day hike,’” Willerslev told Live Science. “Humans won’t take the trip unless you have resources to sustain yourself along the way.”Additional evidence comes from occupation sites in South America earlier than the time evolutionary anthropologists thought the land bridge was accessible, e.g.,. at pre-Clovis sites in Chile dated 14,000 years ago. PhysOrg calls the old theory “biologically unviable” in light of the new evidence. To get where they got, they would have had to be inventive, using boats or canoes to travel the coastline. Later migrants probably did use the land bridge after enough ice had melted to allow plants and mammals to arrive as food sources (dated 12,600 years ago).Something drove the early arrivals to get to North America by a coastal route, and it wasn’t just hunger. Callaway writes,The fact that early humans advanced to the Americas despite continent-sized glaciers standing in the way has also prompted him to rethink the conventional wisdom that early humans, like other animals, migrated solely in search of food.“Just like people today are trying to reach the top of Mount Everest or the South Pole, I’m sure these hunter-gatherers were also explorers and curious about what would be on the other side of these glacier caps,” he says. “When you first reach California, why would you go further? Why not just stay in the Bay Area?”A recent paper in PNAS came to the same conclusion, National Geographic points out. Studying fossil DNA, a team constrained the date of migration by showing that bison were not available as a food source till after the first arrivers had crossed over.European Farmer-GatherersAnother upset for anthropologists comes from the other side of the globe. Writing in The Conversation, Gaffney and Allaby present a conundrum that “Ancient Britons had wheat 2,000 years before they had farms.” If they were smart enough to trade, how could they enjoy the Breakfast of Champions for millennia without becoming curious about how to manufacture Wheaties themselves? The dates are 8,000 years after the curious explorers in Siberia had already reached Chile by boat.Wheat has been found in a settlement on England’s south coast dating back to 6000BC – 2000 years before farming reached Britain. This finding overturns many cherished archaeological beliefs – or myths – about the era. Though they were once patronised as simplistic hunter-gatherers, it turns out early Britons must have been active traders with the agricultural superpowers of their day in France and the Balkans. It’s time to reassess Mesolithic man.PhysOrg writes that “hunger-gatherers experimented with farming in Turkey before migrating to Europe.” An open-access paper in Current Biology admits that “the timing and process of this movement remain unclear.” Farming appeared in several areas “quasi-synchronously” in Anatolia (modern Turkey) in the late 10th and 9th centuries BC, they say, reaching Europe shortly after. This despite many tens of thousands of years of ancestors equal in stature and mental capacity never imagining how it would have made life easier to plant some seeds instead of looking all over for them.Chuck Klosterman has a new book out, But What If We’re Wrong? that posits everything we believe today will be wrong in 500 years. In an interview on Live Science, Jim McLauchlin has fun with the idea, demonstrated by so many cases through history. Neither, however, sees the premise to be self-refuting. Nor does Chuck see his suspicion that we’re living in a computer simulation to be self-defeating (i.e., the simulation made him say that). Indeed, comparing the early humans with thinkers today, one could argue we are devolving from common sense to insanity.Do you see why evolutionists are always surprised? They have a strong need to maintain a false view of human beings as primitive primates gradually emerging into the light of consciousness, self-awareness, cooperation and civilization over millions of years. But everywhere they look, they find people just as smart and curious as we are. They cannot account for the explosive appearance of farming in just a short time. Why didn’t Cro-magnons and Neanderthals ever think of it? Who could believe for a minute that early Britons spent 2,000 years trading with “agricultural superpowers” on the continent without learning how to grow wheat themselves? Something is vastly wrong with the secular view of history and human nature. You know just what it is: refusal to listen to the Eyewitness about what really happened.(Visited 26 times, 1 visits today)FacebookTwitterPinterestSave分享0