Our take on the week: As a UK adviser is fired over politically unpalatable advice, and an English teacher is suspended over an article about animal sexuality, the fate of facts is on the line.
"The discovery of an early human fossil in southern China may challenge the commonly held idea that modern humans originated out of Africa.
Jin Changzhu and colleagues of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, announced to Chinese media last week that they have uncovered a 110,000 year old putative Homo sapiens mandible from a cave in southern China's Guangxi province.
The mandible has a protruding chin like that of Homo sapiens, but the thickness of the jaw is indicative of more primitive hominins, suggesting that the fossil could derive from interbreeding.
If confirmed, the finding would lend support to the"multiregional hypothesis". This says that modern humans descend from Homo sapiens coming out of Africa who then interbred with more primitive humans on other continents. In contrast, the prevailing "Out of Africa" hypothesis holds that modern humans are the direct descendents of people who spread out of Africa to other continents around 100,000 years ago.
The study will appear in Chinese Science Bulletin later this month."http://www.newscientist.com/article/dn18093-chinese-challenge-to-out-of-africa-theory.h... more
Does running a marathon push the body further than it is meant to go?
The conventional wisdom is that distance running leads to debilitating wear and tear, especially on the joints. But that hasn’t stopped runners from flocking to starting lines in record numbers.
Last year in the United States, 425,000 marathoners crossed the finish line, an increase of 20 percent from the beginning of the decade, Running USA says. Next week about 40,000 people will take part in the New York City Marathon. Injury rates have also climbed, with some studies reporting that 90 percent of those who train for the 26.2-mile race sustain injuries in the process.
But now a best-selling book has reframed the debate about the wisdom of distance running. In “Born to Run” (Knopf), Christopher McDougall, an avid runner who had been vexed by injuries, explores the world of the Tarahumara Indians of Mexico, a tribe known for running extraordinary distances in nothing but thin-soled sandals.
Mr. McDougall makes the case that running isn’t inherently risky. Instead, he argues that the commercialization of urban marathons encourages overzealous training, while the promotion of high-tech shoes has led to poor running form and a rash of injuries.
Though Charles Darwin thought of religion as a tribal survival strategy, in 1879 he wrote that "I think that generally ... an agnostic would be the most correct description of my state of mind.” When he published The Origin of Species 150 years ago, he deliberately avoided the subject of the origin of life. This, coupled with the mention of the 'Creator' in the last paragraph of the book, led many to believe he was not willing to commit on the matter.
Now, an international team, led by Juli Peretó of the Cavanilles Institute in Valencia, refutes that idea and shows that the British naturalist did explain in other documents how our first ancestors could have come into being.
"All organic beings that have lived on Earth could be descended from some primordial form", explained Darwin in The Origin of Species in 1859. Despite this statement, the scientist took it upon himself to understand the evolutional processes underlying biodiversity.
"Darwin was convinced of the incredible importance of this issue for his theory and he had an amazingly modern materialist and evolutional vision about the transition of inanimate chemical matter into living matter, despite being very aware of Pasteur's experiments in opposition to spontaneous generation", Juli Peretó, principal author of this study and researcher at the Cavanilles Institute of Evolutional Biology and Biodiversity at the University of Valencia, explains to SINC.
The study, which is published in the latest issue of the journal Origins of Life and Evolution of Biospheres, demonstrates that Darwin had an advanced idea on the origin of the first species, and was troubled by the problem. "It is utterly wrong to think that he was invoking a divine intervention; it is also well documented that the mention of the 'Creator' in The Origin of the Species was an addition for appearance's sake that he later regretted", affirms Peretó.
According to the researchers, all Darwin's opinions on the origin of life can be found in his private correspondence and in his notebooks. The exception is a review of a book on foraminiferous microorganisms published in 1863 in the London social club Athenaeum, where Darwin "lets his opinion on the spontaneous generation be known".
The international team, comprising Spanish, US and Mexican scientists, has not only examined in detail the phrases, texts and paragraphs of the letters, but has also put into context all Darwin's opinions on the origins of life, available online and in the original manuscripts.
A comment in a notebook dating back to 1837, in which Darwin explains that "the intimate relationship between the vital phenomena with chemistry and its laws makes the idea of spontaneous generation conceivable", gave the researchers their clue.
In another famous letter sent in 1871 to his friend, the English botanist and explorer Joseph D. Hooker, Charles Darwin imagines a small, warm pool where the inanimate matter would arrange itself into evolutionary matter, aided by chemical components and sufficient sources of energy.
In other letters, the naturalist admitted to colleagues such as Alfred Russel Wallace or Ernst Haeckel that spontaneous generation was important to the coherence of the theory. However, "at the same time, he acknowledged that science was not advanced enough to deal with the question (hence his reluctance to speak of it in public) and that he would not live to see it resolved", Peretó points out.Though Charles Darwin thought of religion as a tribal survival strategy, in 1879 he... more
Unfortunately, it has been discovered that Ida has no known descendants.
"It was billed as one of the most important fossil finds in history, a “missing link” that would challenge everything we knew about human evolution.
Darwinius masillae, the primitive primate that was unveiled to the world with huge fanfare and a Sir David Attenborough documentary in May, seems now to have been less of a missing link than an evolutionary dead end.
Far from being an ancestor to humans, the lemur-like creature from 47 million years ago belongs to an entirely different branch of the primate family tree that has left no known descendants, research has indicated.
When Jørn Hurum, of the University of Oslo Natural History Museum, announced the discovery of the astonishingly well-preserved fossil, he described it as “the first link to all humans.”Unfortunately, it has been discovered that Ida has no known descendants.
"It was... more
Emory University researchers have identified the first fish known to have switched from ultraviolet vision to violet vision, or the ability to see blue light. The discovery is also the first example of an animal deleting a molecule to change its visual spectrum.
Their findings on scabbardfish, linking molecular evolution to functional changes and the possible environmental factors driving them, were published Oct. 13 in the Proceedings of the National Academy of Sciences.
"This multi-dimensional approach strengthens the case for the importance of adaptive evolution," says evolutionary geneticist Shozo Yokoyama, who led the study. "Building on this framework will take studies of natural selection to the next level."
The research team included Takashi Tada, a post-doctoral fellow in biology, and Ahmet Altun, a post-doctoral fellow in biology and computational chemistry.
Vision 'like a painting'
For two decades, Yokoyama has done groundbreaking work on the adaptive evolution of vision in vertebrates. Vision serves as a good study model, since it is the simplest of the sensory systems. For example, only four genes are involved in human vision.
"It's amazing, but you can mix together this small number of genes and detect a whole color spectrum," Yokoyama says. "It's just like a painting."
The common vertebrate ancestor possessed UV vision. However, many species, including humans, have switched from UV to violet vision, or the ability to sense the blue color spectrum.
From the ocean depths
Fish provide clues for how environmental factors can lead to such vision changes, since the available light at various ocean depths is well quantified. All fish previously studied have retained UV vision, but the Emory researchers found that the scabbardfish has not. To tease out the molecular basis for this difference, they used genetic engineering, quantum chemistry and theoretical computation to compare vision proteins and pigments from scabbardfish and another species, lampfish. The results indicated that scabbardfish shifted from UV to violet vision by deleting the molecule at site 86 in the chain of amino acids in the opsin protein.
"Normally, amino acid changes cause small structure changes, but in this case, a critical amino acid was deleted," Yokoyama says.
More examples likely
"The finding implies that we can find more examples of a similar switch to violet vision in different fish lineages," he adds. "Comparing violet and UV pigments in fish living in different habitats will open an unprecedented opportunity to clarify the molecular basis of phenotypic adaptations, along with the genetics of UV and violet vision."
Scabbardfish spend much of their life at depths of 25 to 100 meters, where UV light is less intense than violet light, which could explain why they made the vision shift, Yokoyama theorizes. Lampfish also spend much of their time in deep water. But they may have retained UV vision because they feed near the surface at twilight on tiny, translucent crustaceans that are easier to see in UV light.
A framework for evolutionary biology
Last year, Yokoyama and collaborators completed a comprehensive project to track changes in the dim-light vision protein opsin in nine fish species, chameleons, dolphins and elephants, as the animals spread into new environments and diversified over time. The researchers found that adaptive changes occur by a small number of amino acid substitutions, but most substitutions do not lead to functional changes.
"Evolutionary biology is filled with arguments that are misleading, at best," Yokoyama says. "To make a strong case for the mechanisms of natural selection, you have to connect changes in specific molecules with changes in phenotypes, and then you have to connect these changes to the living environment."Emory University researchers have identified the first fish known to have switched... more
It's been a rather big year for Charles Darwin. 2009 is the bicentennial of the man's birth and the 150th anniversary of the publication of "The Origin of Species," and the explorer and naturalist has been the subject of books (including a graphic novel adaptation of "The Origin of Species"), a movie starring Jennifer Connelly (with its own ensuing controversy), and even a viral video hit starring "Growing Pains" actor Kirk Cameron. Given that evolutionary biology is Richard Dawkins' area of expertise, it's unsurprising that the British scientist, atheist and controversial author of "The God Delusion" has also gotten on the bandwagon -- in rather ambitious fashion.
In "The Greatest Show on Earth," Dawkins has written what is essentially a layperson's primer for the theory of evolution. Dawkins aims to explain to the everyday reader why evolution isn't a "theory" but a fact and that we need only look around us to find evidence of its existence -- from continental drift to the reproductive habits of wasps. Dawkins uses simple language, elaborate metaphors and color photographs to make his point, and the result is a convincing, if occasionally dry, overview of evolutionary biology. It's also clear, from the book's first pages, that Dawkins isn't very tolerant of his creationist opponents (the book includes a memorably confrontational encounter with Wendy Wright, the creationist president of Concerned Women for America).
Salon spoke with Dawkins via Skype about creationism's popularity in America, its connection with religion, and how he feels about his own notoriety. A video excerpt of the conversation is posted below.
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(excerpt)
Q: Do you think that there's any one particular piece of evidence that will change people's minds about creationism, or do you think that it's really just a question of a gradual erosion of people's belief systems?
A: I wouldn't expect their minds to be changed by fossils, really. I think the more convincing evidence is the evidence from comparison of modern animals and plants, because we have so many different species, and by comparing them with each other, particularly comparing the molecular genetics which is nowadays very easily done. All living creatures have the same genetic code, so you have an exact digital count of the similarities between every species and every other species, and if you look at that pattern of similarities it falls perfectly into a hierarchical tree. It's a family tree. And even better than that, everything you look at -- every different gene you look at -- gives you the same family tree. That's remarkably persuasive evidence to anybody who attends to it long enough to understand.It's been a rather big year for Charles Darwin. 2009 is the bicentennial of the man's... more
WASHINGTON — The Smithsonian's National Museum of Natural History plans to open a hall next year dedicated to the story of human evolution over 6 million years, officials announced Wednesday.WASHINGTON — The Smithsonian's National Museum of Natural History plans to open a... more
LONDON (Reuters) - Many prehistoric Australian aboriginals could have outrun world 100 and 200 meters record holder Usain Bolt in modern conditions.
Some Tutsi men in Rwanda exceeded the current world high jump record of 2.45 meters during initiation ceremonies in which they had to jump at least their own height to progress to manhood.
Any Neanderthal woman could have beaten former bodybuilder and current California governor Arnold Schwarzenegger in an arm wrestle.
These and other eye-catching claims are detailed in a book by Australian anthropologist Peter McAllister entitled "Manthropology" and provocatively sub-titled "The Science of the Inadequate Modern Male."
McAllister sets out his stall in the opening sentence of the prologue.
"If you're reading this then you -- or the male you have bought it for -- are the worst man in history.
"No ifs, no buts -- the worst man, period...As a class we are in fact the sorriest cohort of masculine Homo sapiens to ever walk the planet."LONDON (Reuters) - Many prehistoric Australian aboriginals could have outrun world 100... more
Meet the latest pterosaur - winged prehistoric reptile. Darwinopterus or Darwin's Wing is from China circa the Jurassic age. Another example of just how far Charles Darwin was ahead of his time.Meet the latest pterosaur - winged prehistoric reptile. Darwinopterus or Darwin's Wing... more
“All that is Solid Melts into the Air” is a fascinating 1-minute short film that was directed, designed and animated by Marco Vinicio Morales. Morales describes the film as a visual and poetic journey influenced by art, design, architecture and photography. It illustrates the process whereby under the violent irruption of forms and structures, everything flows towards a constant evolution.
This piece includes a number of b&w photographs from the film, as well as the very intriguing short film, “All that is Solid Melts into the Air.”“All that is Solid Melts into the Air” is a fascinating 1-minute short film that... more
French-British anthropologist, Maurice Bloch, of the London School of Economics believes that humans alone practice religion because they're the only creatures to have evolved imagination. The development of imagination occurred at the time of the Upper Palaeolithic 'revolution' 40-50,000 years ago. Bloch challenges the popular notion that religion evolved and spread because it promoted social bonding, as has been argued by some anthropologists (Image is prehistoric rock painting from south of Spain).
According to Bloch's theory, initially humans had to develop the essential brain architecture to imagine things and beings that don't exist physically, and the possibility that people somehow survive on after their death.
Once this was acquired, we had access to a form of social interaction unavailable to any other creatures on the planet. Exclusively, humans could use what Bloch calls the "transcendental social" to unite with groups, such as nations and clans, or even with imaginary groups such as the dead. He explained that the transcendental social also permits humans to follow the idealized codes of conduct linked with religion.
"What the transcendental social requires is the ability to live very largely in the imagination," New Scientist magazine quoted him, as saying.
"One can be a member of a transcendental group, or a nation, even though one never comes in contact with the other members of it. Moreover, the composition of such groups, whether they are clans or nations, may equally include the living and the dead," he added.
He argues that no animals, not even our nearest relatives the chimpanzees, can do this. Instead, he says, they're restricted to the routine and Machiavellian social interactions of everyday life.
The reason for this, he says, is that they can't imagine beyond this immediate social circle, or backwards and forwards in time, in the same way that humans can.
Bloch believes our ancestors evolved the essential neural architecture to imagine before or around a time called the Upper Palaeological Revolution, the final sub-division of the Stone Age.
"The transcendental network can, with no problem, include the dead, ancestors and gods, as well as living role holders and members of essentialised groups," he said.
"Ancestors and gods are compatible with living elders or members of nations because all are equally mysterious invisible, in other words transcendental," he added.But Bloch argues that religion is only one expression of this exceptional ability to form bonds with non-existent or distant people or value-systems.
"Religious-like phenomena in general are an inseparable part of a key adaptation unique to modern humans, and this is the capacity to imagine other worlds, an adaptation that I argue is the very foundation of the sociality of modern human society," he said.
"Once we realize this omnipresence of the imaginary in the everyday, nothing special is left to explain concerning religion," he added.French-British anthropologist, Maurice Bloch, of the London School of Economics... more
Although It has taken homo sapiens several million years to evolve from the apes, the useful information in our DNA, has probably changed by only a few million bits. So the rate of biological evolution in humans, Stephen Hawking points out in his Life in the Universe lecture, is about a bit a year.
"By contrast," Hawking says, "there are about 50,000 new books published in the English language each year, containing of the order of a hundred billion bits of information. Of course, the great majority of this information is garbage, and no use to any form of life. But, even so, the rate at which useful information can be added is millions, if not billions, higher than with DNA."............Although It has taken homo sapiens several million years to evolve from the apes, the... more
Atheist Richard Dawkins, appearing on The O'Reilly Factor, gave a good showing, while Bill O'Reilly was reduced to calling science "Fascism". All in all, no surprises. O'Reilly is not much of an intellect, and the discussion is fairly shallow. Nevertheless, it is entertaining to watch Dawkins quietly and patiently reduce O'Reilly to absurdity.Atheist Richard Dawkins, appearing on The O'Reilly Factor, gave a good showing, while... more
Should teachers turn to creationism to explain the gaps in evolution? Bill O'Reilly thinks so. Unsurprisingly, prominent atheist Richard Dawkins disagrees. "If a particular scientific theory doesn't work, do some better science," Dawkins said. O'Reilly also said that only teaching evolution in public schools is "fascism"Should teachers turn to creationism to explain the gaps in evolution? Bill O'Reilly... more
What can scientists learn about the world by knowing how all living things are related to each other?What can scientists learn about the world by knowing how all living things are related... more
This video presents a very brief glimpse into what I do as a professional researcher studying "my birds" -- the parrots of the South Pacific Ocean. It features interviews with one of the scientists whom I worked with when I was in grad school at the University of Washington: Scott Edwards, who now is at Harvard University.This video presents a very brief glimpse into what I do as a professional researcher... more
WHEN Nobel prize-winning atmospheric chemist Paul Crutzen coined the word Anthropocene around 10 years ago, he gave birth to a powerful idea: that human activity is now affecting the Earth so profoundly that we are entering a new geological epoch.
The Anthropocene has yet to be accepted as a geological time period, but if it is, it may turn out to be the shortest - and the last. It is not hard to imagine the epoch ending just a few hundred years after it started, in an orgy of global warming and overconsumption.
Let's suppose that happens. Humanity's ever-expanding footprint on the natural world leads, in two or three hundred years, to ecological collapse and a mass extinction. Without fossil fuels to support agriculture, humanity would be in trouble. "A lot of things have to die, and a lot of those things are going to be people," says Tony Barnosky, a palaeontologist at the University of California, Berkeley. In this most pessimistic of scenarios, society would collapse, leaving just a few hundred thousand eking out a meagre existence in a new Stone Age.
Whether our species would survive is hard to predict, but what of the fate of the Earth itself? It is often said that when we talk about "saving the planet" we are really talking about saving ourselves: the planet will be just fine without us. But would it? Or would an end-Anthropocene cataclysm damage it so badly that it becomes a sterile wasteland?
The only way to know is to look back into our planet's past. Neither abrupt global warming nor mass extinction are unique to the present day. The Earth has been here before. So what can we expect this time?
Take greenhouse warming. Climatologists' biggest worry is the possibility that global warming could push the Earth past two tipping points that would make things dramatically worse. The first would be the thawing of carbon-rich peat locked in permafrost. As the Arctic warms, the peat could decompose and release trillions of tonnes of carbon into the atmosphere - perhaps exceeding the 3 trillion tonnes that humans could conceivably emit from fossil fuels. The second is the release of methane stored as hydrate in cold, deep ocean sediments. As the oceans warm and the methane - itself a potent greenhouse gas - enters the atmosphere, it contributes to still more warming and thus accelerates the breakdown of hydrates in a vicious circle.
"If we were to blow all the fossil fuels into the atmosphere, temperatures would go up to the point where both of these reservoirs of carbon would be released," says oceanographer David Archer of the University of Chicago. No one knows how catastrophic the resulting warming might be.
That's why climatologists are looking with increasing interest at a time 55 million years ago called the Palaeocene-Eocene thermal maximum, when temperatures rose by up to 9 °C in a few thousand years - roughly equivalent to the direst forecasts for present-day warming. "It's the most recent time when there was a really rapid warming," says Peter Wilf, a palaeobotanist at Pennsylvania State University in University Park. "And because it was fairly recent, there are a lot of rocks still around that record the event."
By measuring ocean sediments deposited during the thermal maximum, geochemist James Zachos of the University of California, Santa Cruz, has found that the warming coincided with a huge spike in atmospheric CO2. Between 5 and 9 trillion tonnes of carbon entered the atmosphere in no more than 20,000 years (Nature, vol 432, p 495). Where could such a huge amount have come from?
Volcanic activity cannot account for the carbon spike, Zachos says. Instead, he blames peat decomposition, which would have happened not from melting permafrost - it was too warm for permafrost - but through climatic drying. The fossil record of plants from this time testifies to just such a drying episode.
Continued at link . . .WHEN Nobel prize-winning atmospheric chemist Paul Crutzen coined the word Anthropocene... more
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