Science Geekery!

[Bizarro]

<a href="http://www.youtube.com/v/zSgiXGELjbc" target="_blank">http://www.youtube.com/v/zSgiXGELjbc</a>

[Bizarro]

Oldest "Human" Skeleton Found--Disproves "Missing Link"
 
Move over, Lucy. And kiss the missing link goodbye.

Scientists today announced the discovery of the oldest fossil skeleton of a human ancestor. The find reveals that our forebears underwent a previously unknown stage of evolution more than a million years before Lucy, the iconic early human ancestor specimen that walked the Earth 3.2 million years ago.

The centerpiece of a treasure trove of new fossils, the skeleton—assigned to a species called Ardipithecus ramidus—belonged to a small-brained, 110-pound (50-kilogram) female nicknamed "Ardi." (See pictures of Ardipithecus ramidus.)

The fossil puts to rest the notion, popular since Darwin's time, that a chimpanzee-like missing link—resembling something between humans and today's apes—would eventually be found at the root of the human family tree. Indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings.

Ardi instead shows an unexpected mix of advanced characteristics and of primitive traits seen in much older apes that were unlike chimps or gorillas (interactive: Ardi's key features). As such, the skeleton offers a window on what the last common ancestor of humans and living apes might have been like.

Announced at joint press conferences in Washington, D.C., and Addis Ababa, Ethiopia, the analysis of the Ardipithecus ramidus bones will be published in a collection of papers tomorrow in a special edition of the journal Science, along with an avalanche of supporting materials published online.

"This find is far more important than Lucy," said Alan Walker, a paleontologist from Pennsylvania State University who was not part of the research. "It shows that the last common ancestor with chimps didn't look like a chimp, or a human, or some funny thing in between." (Related: "Oldest Homo Sapiens Fossils Found, Experts Say" [June 11, 2003].)

Ardi Surrounded by Family

The Ardipithecus ramidus fossils were discovered in Ethiopia's harsh Afar desert at a site called Aramis in the Middle Awash region, just 46 miles (74 kilometers) from where Lucy's species, Australopithecus afarensis, was found in 1974. Radiometric dating of two layers of volcanic ash that tightly sandwiched the fossil deposits revealed that Ardi lived 4.4 million years ago.

Older hominid fossils have been uncovered, including a skull from Chad at least six million years old and some more fragmentary, slightly younger remains from Kenya and nearby in the Middle Awash.

While important, however, none of those earlier fossils are nearly as revealing as the newly announced remains, which in addition to Ardi's partial skeleton include bones representing at least 36 other individuals.

"All of a sudden you've got fingers and toes and arms and legs and heads and teeth," said Tim White of the University of California, Berkeley, who co-directed the work with Berhane Asfaw, a paleoanthropologist and former director of the National Museum of Ethiopia, and Giday WoldeGabriel, a geologist at Los Alamos National Laboratory in New Mexico.

"That allows you to do something you can't do with isolated specimens," White said. "It allows you to do biology."

(Related: Rediscover the original Ardipithecus.)

Ardi's Weird Way of Moving

The biggest surprise about Ardipithecus's biology is its bizarre means of moving about.

All previously known hominids—members of our ancestral lineage—walked upright on two legs, like us. But Ardi's feet, pelvis, legs, and hands suggest she was a biped on the ground but a quadruped when moving about in the trees.

Her big toe, for instance, splays out from her foot like an ape's, the better to grasp tree limbs. Unlike a chimpanzee foot, however, Ardipithecus's contains a special small bone inside a tendon, passed down from more primitive ancestors, that keeps the divergent toe more rigid. Combined with modifications to the other toes, the bone would have helped Ardi walk bipedally on the ground, though less efficiently than later hominids like Lucy. The bone was lost in the lineages of chimps and gorillas.

According to the researchers, the pelvis shows a similar mosaic of traits. The large flaring bones of the upper pelvis were positioned so that Ardi could walk on two legs without lurching from side to side like a chimp. But the lower pelvis was built like an ape's, to accommodate huge hind limb muscles used in climbing.

Even in the trees, Ardi was nothing like a modern ape, the researchers say.

Modern chimps and gorillas have evolved limb anatomy specialized to climbing vertically up tree trunks, hanging and swinging from branches, and knuckle-walking on the ground.

While these behaviors require very rigid wrist bones, for instance, the wrists and finger joints of Ardipithecus were highly flexible. As a result Ardi would have walked on her palms as she moved about in the trees—more like some primitive fossil apes than like chimps and gorillas.

"What Ardi tells us is there was this vast intermediate stage in our evolution that nobody knew about," said Owen Lovejoy, an anatomist at Kent State University in Ohio, who analyzed Ardi's bones below the neck. "It changes everything."

Against All Odds, Ardi Emerges

The first, fragmentary specimens of Ardipithecus were found at Aramis in 1992 and published in 1994. The skeleton announced today was discovered that same year and excavated with the bones of the other individuals over the next three field seasons. But it took 15 years before the research team could fully analyze and publish the skeleton, because the fossils were in such bad shape.

After Ardi died, her remains apparently were trampled down into mud by hippos and other passing herbivores. Millions of years later, erosion brought the badly crushed and distorted bones back to the surface.

They were so fragile they would turn to dust at a touch. To save the precious fragments, White and colleagues removed the fossils along with their surrounding rock. Then, in a lab in Addis, the researchers carefully tweaked out the bones from the rocky matrix using a needle under a microscope, proceeding "millimeter by submillimeter," as the team puts it in Science. This process alone took several years.

Pieces of the crushed skull were then CT-scanned and digitally fit back together by Gen Suwa, a paleoanthropologist at the University of Tokyo.

In the end, the research team recovered more than 125 pieces of the skeleton, including much of the feet and virtually all of the hands—an extreme rarity among hominid fossils of any age, let alone one so very ancient.

"Finding this skeleton was more than luck," said White. "It was against all odds."

Ardi's World

The team also found some 6,000 animal fossils and other specimens that offer a picture of the world Ardi inhabited: a moist woodland very different from the region's current, parched landscape. In addition to antelope and monkey species associated with forests, the deposits contained forest-dwelling birds and seeds from fig and palm trees.

Wear patterns and isotopes in the hominid teeth suggest a diet that included fruits, nuts, and other forest foods.

If White and his team are right that Ardi walked upright as well as climbed trees, the environmental evidence would seem to strike the death knell for the "savanna hypothesis"—a long-standing notion that our ancestors first stood up in response to their move onto an open grassland environment.

Sex for Food

Some researchers, however, are unconvinced that Ardipithecus was quite so versatile.

"This is a fascinating skeleton, but based on what they present, the evidence for bipedality is limited at best," said William Jungers, an anatomist at Stony Brook University in New York State.

"Divergent big toes are associated with grasping, and this has one of the most divergent big toes you can imagine," Jungers said. "Why would an animal fully adapted to support its weight on its forelimbs in the trees elect to walk bipedally on the ground?"

One provocative answer to that question—originally proposed by Lovejoy in the early 1980s and refined now in light of the Ardipithecus discoveries—attributes the origin of bipedality to another trademark of humankind: monogamous sex.

Virtually all apes and monkeys, especially males, have long upper canine teeth—formidable weapons in fights for mating opportunities.

But Ardipithecus appears to have already embarked on a uniquely human evolutionary path, with canines reduced in size and dramatically "feminized" to a stubby, diamond shape, according to the researchers. Males and female specimens are also close to each other in body size.

Lovejoy sees these changes as part of an epochal shift in social behavior: Instead of fighting for access to females, a male Ardipithecus would supply a "targeted female" and her offspring with gathered foods and gain her sexual loyalty in return.

To keep up his end of the deal, a male needed to have his hands free to carry home the food. Bipedalism may have been a poor way for Ardipithecus to get around, but through its contribution to the "sex for food" contract, it would have been an excellent way to bear more offspring. And in evolution, of course, more offspring is the name of the game (more: "Did Early Humans Start Walking for Sex?").

Two hundred thousand years after Ardipithecus, another species called Australopithecus anamensis appeared in the region. By most accounts, that species soon evolved into Australopithecus afarensis, with a slightly larger brain and a full commitment to a bipedal way of life. Then came early Homo, with its even bigger brain and budding tool use.

Did primitive Ardipithecus undergo some accelerated change in the 200,000 years between it and Australopithecus—and emerge as the ancestor of all later hominids? Or was Ardipithecus a relict species, carrying its quaint mosaic of primitive and advanced traits with it into extinction?

Study co-leader White sees nothing about the skeleton "that would exclude it from ancestral status." But he said more fossils would be needed to fully resolve the issue.

Stony Brook's Jungers added, "These finds are incredibly important, and given the state of preservation of the bones, what they did was nothing short of heroic.

But this is just the beginning of the story."

[Doctor Rock]

I don't get this: "The fossil puts to rest the notion, popular since Darwin's time, that a chimpanzee-like missing link—resembling something between humans and today's apes—would eventually be found at the root of the human family tree. Indeed, the new evidence suggests that the study of chimpanzee anatomy and behavior—long used to infer the nature of the earliest human ancestors—is largely irrelevant to understanding our beginnings."

They're knocking down a strawman!  As far as I know, primatologists (I'm specifically thinking of Franz De Waal) are fully aware that chimps and humans kept evolving each their own way, and that studying chimps is useful in itself.   De Waal, for instance, often makes comparisons of human and chimp behaviour, but he does them in order to demonstrate that certain things that many believe are unique to humans (like morality and a sense of justice) are present in apes.  I read a bunch of his books, and he never mentioned that he was studying chimps in order to figure out how the missing link behaved. 

Journalists, and particularly journalists covering subjects they believe readers will find dull (like science), like a bit of controversy.  If there isn't any, they'll invent some. 

[Bizarro]

That part was kind of silly. But the new discovery (one largely complete skeleton and 36 partials) of a new human ancestor species that predates "Lucy" by 1.2 million years is a pretty big deal.

Want an even funnier misrepresentation of this story? At least as many articles about this on Google News lead off with "missing link found!" as "disproves missing link theory."

[Bizarro]

http://www.bazian.com/pdfs/HowToReadANewsStory_vers03_26Nov08.pdf

How to read articles about health and healthcare
By Dr Alicia White
If you’ve just read a health-related headline that’s caused you to spit out your morning coffee (“Coffee causes cancer” usually does the trick) it’s always best to follow the Blitz slogan: “Keep Calm and Carry On”. On reading further you’ll often find the headline has left out something important, like “Injecting five rats with really highly concentrated coffee solution caused some changes in cells that might lead to tumours eventually. (Study funded by The Association of Tea Marketing)”.

The most important rule to remember: “Don’t automatically believe the headline”.

It is there to draw you into buying the paper and reading the story. Would you read an article called “Coffee pretty unlikely to cause cancer, but you never know”? Probably not.  Before spraying your newspaper with coffee in the future, you need to interrogate
the article to see what it says about the research it is reporting on. Bazian (the company I work for) has interrogated hundreds of articles for Behind The Headlines on NHS Choices, and we’ve developed the following questions to help you figure out which articles you’re going to believe, and which you’re not.

Does the article support its claims with scientific research?

If an article touts a treatment or a lifestyle factor that is supposed to prevent or cause a disease, but doesn’t give any information about the scientific research behind it, or refers to research that has yet to be published, then treat it with caution. A lot of caution, like balling the article up and throwing it in the (recycling) bin. Is the article based on a conference abstract?

Another area for caution: news articles based on conference abstracts. Research presented at conferences is often at a preliminary stage and usually hasn’t been scrutinised by experts in the field. Also conference abstracts rarely provide full details about methods, making it difficult to judge how well the research was conducted. For these reasons, articles based on conference abstracts should be no cause for alarm. Don’t panic or rush off to your GP.

Was the research in humans?

Quite often the “miracle cure” in the headline turns out to have only been tested on cells in the laboratory or on animals. These stories are often accompanied by pictures of humans, creating the illusion that the “miracle cure” came from human studies. Studies in cells and animals are crucial first steps and should not be undervalued. However, many drugs that show promising results in cells in laboratories don’t work in animals, and many drugs that show promising results in animals don’t work in humans. If you read a headline about a drug or food “curing” rats, there is a chance it might cure humans in the future, but unfortunately a larger chance that it won’t. So no need to start eating large amounts of the “wonder food” featured in the article.

How many people did the research study include?

In general, the larger a study the more you can trust its results. Small studies may miss important differences because they lack statistical “power”, and small studies are more susceptible to finding things (including things that are wrong) purely by chance. You can visualise this by thinking about tossing a coin. We know that if we toss a coin the chance of getting a head is the same as that of getting a tail – 50/50. However, if we didn’t know this and we tossed a coin four times and got three heads and one tail, we might conclude that getting heads was more likely than tails. But this chance finding would be wrong. If we tossed the coin 500 times – gave the experiment  more “power” – we’d be much more likely to get an even number of heads and tails, giving us a better idea of the true odds. When it comes to sample sizes, bigger is usually better. So when you see a study conducted in a handful of people, proceed with caution.

Did the study have a control group?

There are many different types of studies, and they are appropriate for answering different types of questions. If the question being asked is about whether a treatment or exposure has an effect or not, then the study needs to have a control group. A control group allows the researchers to compare what happens to people who have the treatment/exposure with what happens to people who don’t. If the study doesn’t have a control group, then it’s difficult to attribute results to the treatment or exposure with any level of certainty. Also, it’s important that the control group is as similar to the treated/exposed group as possible. The best way to achieve this is to randomly assign some people to be in the treated/exposed group and some people to be in the control group. This is what happens in a randomised controlled trial (RCT) which is why they are considered the “gold standard” way of testing the effects of treatments and exposures. So when reading about a drug, food or treatment that is supposed to have an effect, you want to look for evidence of a control group, and ideally evidence that the study was an RCT. Without either, retain some healthy scepticism.

Did the study actually assess what’s in the headline?

This one is a bit tricky to explain without going into a lot of detail about “proxy outcomes”. To avoid doing that, here is the key thought: the research study needs to have examined what is being talked about in the headline and article. (Somewhat alarmingly, this isn’t always the case.) For example, you might read a headline that claims “Tomatoes reduce the risk of heart attacks”. What you need to look for is evidence that the study actually looked at heart attacks. You might instead see that the study found that tomatoes reduce blood pressure. This means that someone has extrapolated that tomatoes must also impact heart attacks, as high blood pressure is a risk factor for heart attacks. Sometimes these extrapolations will prove to be true, but other times they
won’t. So if a news story is focusing on a health outcome that was not examined by the research, treat it with
a grain of salt.

Who paid for and conducted the study?

This is a somewhat cynical point, but one that’s worth making. The majority of trials today are funded by manufacturers of the product being tested – be it a drug, vitamin cream or foodstuff. This means they have a vested interest in the results of the trial which can affect what the researchers find and report in all sorts of conscious and unconscious ways. This is not to say that all manufacturer-sponsored trials are unreliable. Many are very good. But it’s worth looking to see who funded the study to sniff out a potential conflict of interest for yourself.

How can I find out more?

It’s not possible to cover all the questions that need to be asked about research studies in a short article, but we’ve covered some of the major ones. For more, go to Behind the Headlines at www.nhs.uk/news for daily breakdowns of healthcare stories in the media.
www.bazian.com

[Doctor Rock]

Good article, Jeff! 

[Bizarro]

Universe has more entropy than thought
New calculations suggest that the cosmos may be a bit closer to heat death
By Ron Cowen

For all its tumult — erupting stars, colliding galaxies, collapsing black holes — the cosmos is a surprisingly orderly place. Theoretical calculations have long shown that the entropy of the universe — a measure of its disorder — is but a tiny fraction of the maximum allowable amount.

A new calculation of entropy upholds that general result but suggests that the universe is messier than scientists had thought — and slightly further along on its gradual journey to death, two Australian cosmologists conclude.

An analysis by Chas Egan of the Australian National University in Canberra and Charles Lineweaver of the University of New South Wales in Sydney indicates that the collective entropy of all the supermassive black holes at the centers of galaxies is about 100 times higher than previously calculated. Because supermassive black holes are the largest contributor to cosmic entropy, the finding suggests that the entropy of the universe is also about 100 times larger than previous estimates, the researchers reported online September 23 at arXiv.org.

Entropy quantifies the number of different microscopic states that a physical system can have while looking the same on a large scale. For instance, an omelet has higher entropy than an egg because there are more ways for the molecules of an omelet to rearrange themselves and still remain an omelet than for an egg, notes cosmologist Sean Carroll of the California Institute of Technology in Pasadena.

A black hole is the entropy champ because there are myriad ways for all the material that has fallen into it to be arranged microscopically while the black hole retains the same numerical values for its observable properties — charge, mass and spin.

Researchers who previously calculated the cosmic sum of black hole entropy had assumed that, on average, each galaxy houses a 10 million solar-mass black hole at its center. Under this assumption, researchers had determined that supermassive black holes contribute an entropy of about 10102, in units derived from a quantity known as Boltzmann’s constant.
 
In contrast, Egan and Lineweaver relied on new data that included a fuller range of the masses of supermassive black holes rather than just using the average mass. “The upshot was that much more entropy is contributed by a smaller population of much larger, 1-billion-solar-mass black holes,” Egan says.

Carroll says that the team’s calculation looks sensible. “I see no reason to doubt their numbers,” he says.

Having a more reliable entropy estimate is important, says Egan, because for life or other complex phenomena to exist, the entropy of the universe must be less than the maximum possible value. Consider, he notes, when hot water is poured into a cold bath. Initially the hot and cold water are separate and the system is orderly — it has low entropy. But once the hot and cold water are thoroughly mixed, the entropy is maximized and no further heat flow is possible.

In the case of the universe, Egan says, “we'd like to know [when and] if the entropy will eventually reach a maximum value, marking the end of all dissipative processes, including life.” Physicists have dubbed that maximum entropy “heat death.”

Egan and Lineweaver’s new value for the entropy of the universe is still a billionth of a billionth the maximum possible entropy that researchers have estimated. Nonetheless, the new value “indicates that that the universe is a bit closer to the heat death than previously computed,” comments theorist Paul Davies of Arizona State University in Tempe.

Not everyone agrees that the higher entropy contributed by supermassive black holes puts the universe closer to heat death. Theorist Ned Wright of the University of California, Los Angeles says that because the extra entropy is locked inside the black holes, the rest of the universe should have lower entropy and be further away from heat death.     

The new entropy calculation also highlights a cosmic puzzle, Carroll says. The entropy was relatively small in the early universe (1088), bigger now (10104), but still falls far short of the maximum (10122). No known physical principle can explain why the cosmic entropy is so low. But it’s a good thing because the low value “is responsible for everything we experience about the [unidirectional] flow of time — breaking eggs, growing older and dying, remembering the past but not the future,” notes Carroll. “The universe is incredibly more orderly than it has any right to be. Egan and Lineweaver have shown that it's just a bit more disorderly than we thought.”

[Bizarro]

To which the natural response is:

[Doctor Rock]

From the Cosmic Variance blog:

General relativity, Einstein’s theory of gravity and spacetime, has been pretty successful over the years. It’s passed numerous tests in the Solar System, scored a Nobel-worthy victory with the binary pulsar, and gets the right answer even when extrapolated back to the first one second after the Big Bang. But no scientific theory is sacred. Even though GR is both aesthetically compelling and an unquestioned empirical success, it’s our job as scientists to keep probing it in different ways. Especially when it comes to astrophysics, where we need dark matter and dark energy to explain what we see, it makes sense to put Einstein to the most stringent tests we can devise.
So here is a new such test, courtesy of Rachel Bean of Cornell. She combines a suite of cosmological data, especially measurements of weak gravitational lensing from the Hubble Space Telescope, to see whether GR correctly describes the behavior of large-scale structure in the universe. And the surprising thing is — it doesn’t. At the 98% confidence level, Rachel finds that general relativity is inconsistent with the data. I’m not sure why we haven’t been reading about this in the science media or even on other blogs — it’s certainly a newsworthy result. Admittedly, the smart money is still that there is some tricky thing that hasn’t yet been noticed and Einstein will eventually come through the victor, but this is serious work by a respected cosmologist. Either the result is wrong, and we should be working hard to find out why, or it’s right, and we’re on the cusp of a revolution.

[Bizarro]

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[Bizarro]

<a href="http://www.youtube.com/v/e7DkeQ0roAM" target="_blank">http://www.youtube.com/v/e7DkeQ0roAM</a>

[Doctor Rock]

The two bacteria who are staph joke made me groan... But in a good way.
 
Two hydrogens walk into a bar. The first one says "Oh, no, I've lost an electron!" The other one says "Are you sure?" The first one answers "I'm positive!"

I love nerdy science jokes.

[Bizarro]

http://www.theaustralian.com.au/news/health-science/watch-this-space/story-e6frg8gf-1225710664198

AFTER you've spent more than 20 years hunting for an alien signal, you think you'd be celebrating if you noticed a mysterious pulse suddenly rising up on your computer readouts. A regular pulse, amid the random clatter of the cosmos, suggests that someone very smart at the other end is sending a message.

But when Ragbir Bhathal, an astrophysicist at the University of Western Sydney, who teaches the only university-based course on SETI (search for extraterrestrial intelligence) in Australia, detected the suspicious signal on a clear night last December, he knew better than to crack open the special bottle of champagne he has tucked away for the history-making occasion.

Instead, he's spent the past few months meticulously investigating whether the unrecognised signature was caused by a glitch in his instrumentation, a rogue astrophysical phenomenon, or some unknown random noise.

[Doctor Rock]

From the Scientific American web site: Seven Answers to Climate Contrarian Nonsense

[Bizarro]

Ancient Amazon civilisation laid bare by felled forest

Signs of what could be a previously unknown ancient civilisation are emerging from beneath the felled trees of the Amazon. Some 260 giant avenues, ditches and enclosures have been spotted from the air in a region straddling Brazil's border with Bolivia.

The traditional view is that before the arrival of the Spanish and Portuguese in the 15th century there were no complex societies in the Amazon basin – in contrast to the Andes further west where the Incas built their cities. Now deforestation, increased air travel and satellite imagery are telling a different story.

"It's never-ending," says Denise Schaan of the Federal University of Pará in Belém, Brazil, who made many of the new discoveries from planes or by examining Google Earth images. "Every week we find new structures." Some of them are square or rectangular, while others form concentric circles or complex geometric figures such as hexagons and octagons connected by avenues or roads. The researchers describe them all as geoglyphs.

Garden villages

Their discovery, in an area of northern Bolivia and western Brazil, follows other recent reports of vast sprawls of interconnected villages known as "garden cities" in north central Brazil, dating from around AD 1400. But the structures unearthed at the garden city sites are not as consistently similar or geometric as the geoglyphs, Schaan says.

"I firmly believe that the garden cities of Xingu and the geoglyphs were not directly related," says Martti Pärssinen of the Finnish Cultural and Academic Institutes in Madrid, Spain, who works with Schaan. "Nevertheless, both discoveries demonstrate that [upland] areas of western Amazonia were heavily populated much before the European incursion."

The geoglyphs are formed by ditches up to 11 metres wide and 1 to 2 metres deep. They range from 90 to 300 metres in diameter and are thought to date from around 2000 years ago up to the 13th century.

Human habitation

Excavations have unearthed ceramics, grinding stones and other signs of human habitation at some of the sites but not at others. This suggests that some had purely ceremonial roles, while others may also have been used for defence.

Unusually for defensive structures, however, earth was piled up outside the ditches, and they are also highly symmetrical. "When you think about defence you're just building a wall or a trench," says Schaan. "You don't have to do calculations to make it so round or square." Many of the structures are oriented to the north, and the team is investigating whether they might have had astronomical significance.

"Many of the great early civilisations had a riverine basis and the Amazon has long been underestimated and overlooked in that sense," says Colin McEwan, head of the Americas section at the British Museum in London.

Successful societies

Though there is no evidence that the Amazonians built pyramids or invented written language as societies in ancient Egypt or Mesopotamia did, "in terms of a trend towards increasing social complexity and domestication of the landscape, this wasn't just a pristine forest with isolated nomadic tribes", McEwan adds. "These were substantive, sedentary and in the long term very successful cultures."

While some Inca sites lie just 200 kilometres west of the geoglyphs, no Inca objects have been found at the new sites. Neither do they seem to have anything in common with Peru's Nasca geoglyphs.

"I have no doubt that this is only scratching the surface," says Alex Chepstow-Lusty of the French Institute for Andean Studies in Lima, Peru. "The scale of pre-Columbian societies in Amazonia is only slowly coming to light and we are going to be amazed at the numbers of people who lived there, but also in a highly sustainable fashion. Sadly, the economic development and forest clearance that is revealing these pre-Columbian settlement patterns is also the threat to having enough time to properly understand them."