The three layers of the Neandertal cake | Gene Expression

I assume by now that everyone has read A Draft Sequence of the Neandertal Genome. It’s free to all, so you should. At least look at the figures. Also, if you haven’t at least skimmed the supplement, you should do that as well. It’s nearly 200 pages, and basically feels more like a collection of minimally edited papers than anything else. There’s no point in me reviewing the paper, since you can read it, and plenty of others have hit the relevant ground already.

Since there seem to be three main segments of the paper, here are a few minimal thoughts on each.

First, the draft genome. What would you have said if someone came up to you ten years ago and told you that you’d live to to see this? Svante Paabo himself admitted he didn’t think he’d see something like this in his lifetime. There was a lot of hard work that went into figuring out how to get at the genetic material, purify it, and confirm that it was actually from the samples in question and not handler contamination and such (remember that there was a problem with contamination a few years back). To a great extent the focus on the results, instead of the methods, is like critiquing a set of landscape photographs taken from a very high peak. We can’t forget the effort and energy that went into scaling the peak itself. A lot of labor input obviously went into this, but additionally we can thank the fact that we live in a technological society where progress is not only expected, but often can’t be accounted for in our projections of future possibilities. I think that’s a very hopeful thing which makes me a little less pessimistic about the possibility of the magic carpet economy.

Second, the are the comparisons between Neandertals, modern humans, and chimpanzees. As Carl Zimmer noted there are an alphabet soup of genes thrown at you in the results. It is hard to make sense of it all, though I did note that genes involved in skin function and phenotype seem to have been the subject of differential evolution between Neandertals and modern humans (i.e., SNP differences in regards to substitutions in the lineages). We already know that there are suggestive signs that Neandertals lost function on pigmentation independently from modern humans. That shouldn’t be too surprising, given that it seems that West and East Eurasians evolved light skin independently. There are some uncertainties about the timing of this, but the different genetic architecture implies that it was unlikely to have occurred immediately after the Out-of-Africa event, and in fact some of the loci imply that depigmentation may have occurred in the Holocene. Skin is famously our biggest organ, so it shouldn’t be that shocking that it is possibly a target of selection, but curious nonetheless (recall that it seems that humans evolved darker skin from a paler ancestor as we lost our fur in the tropics).

Additionally, I think the finding that Neandertals and modern humans seem to share most of the same HARs, regions of the genome where our human lineage seems to differ from other mammals in exhibiting a lot of evolutionary change, is of great interest, though not necessarily surprising. When pointing to Luke Jostins’ post on rates of encephalization, I observed that in some ways it seems like there was a very powerful and consistent lineage specific trend toward greater cranial capacity which had incredible time depth. In The Dawn of Human Culture Richard Klein puts the emphasis on the sharp break between those populations before ~50 thousand years ago, and after. This period is marked by the shift toward behavioral, as opposed to just anatomical, modernity (there were anatomically modern humans in Africa ~200 thousand years ago). Klein’s thesis is that some mutation triggered a radical biocultural change, and was responsible for the Great Leap Forward, the efflorescence of creative symbolic culture which we truly consider the sin qua non of culture. The sharing of HARs between Neandertals and pure humans, and the consistent trend toward encephalization (aside from the post-Ice Age reversal), makes me shift the priors a touch more toward inevitable continuity and away from contingency. I find much of the politics of Robert J. Sawyer’s Neanderthal Parallax series a bit heavy-handed, but his depiction of Neandertals as fundamentally intelligent creatures who differ only on the margins seems a lot more plausible to me now than it was when I first read it in the early to mid-aughts.

Third, and finally, there’s the story of admixture and sex. This is getting all the press, but of course this is the most uncertain, inferential, and speculative aspect of the paper. It’s impressive, but it should open to skepticism, especially after the Out-of-Africa totalism which was ascendant until recently. John Hawks accepts the thrust of the findings, but obviously has his own ideas as to modifications, extensions and qualifications. Dienekes Pontikos favors an alternative interpretation of the data, which the authors point to in the text but dismiss as less parsimonious. My own inclination is to favor the authors in their interpretation of parsimony, but I will admit that this assertion is disputable. Dienekes and others would suggest that it is just as, or more, plausible that the shared variants between non-Africans and Neandertals arise from their common northeast African ancestral population (or some ancestral population of non-Africans and Neandertals). He rightly points out that there may be ancient population substructure within Africa, and using a particular African group as a “reference” for the whole continent may lead to false inferences. The main issue is that the probability of retrieving ancient DNA from northeast African samples in the near future seems low because the conditions for preservation are not optimal (tropical climates famously degrade and recycle biological material more efficiently than temperate or boreal climates). Additionally, using modern northeast African populations is somewhat problematic because there has clearly been some back-migration from the nearby Arabian populations into this area in the medium-term past (the languages of the Ethiopian highlands are Semitic). One supposes that one could differentiate between the African and Arabian components of the genome of Ethiopians and Somalis, but if the admixture event was two to three thousand years ago I presume it would be technically more challenging than an African American, where very few generations have passed since admixture for recombination to fragment long genomic regions attributable to one ancestral population. In other words, how do you distinguish Neandertal variants which arrived back from Eurasia from ancient African ones? (I suppose that the haplotypes would differ so that the genuinely African ones would be more diverse)

But even if you reject the top-line finding, that most of us are not pure human, I think the paper is a game-changer in terms of shifting your priors in relation to evaluating the plausibility of a result which suggests admixture from an ancient non-African population. I found out about the high likelihood of this paper just before the UNM results were presented at the American Anthropological Society meeting, and it is clear in hindsight with the large author list that many people knew what was coming down the pipepline and had recalibrated their assessment of results which indicated admixture. It is perhaps time to go back and take a second look at papers which you skipped over before because it seemed that they may have been spurious or reporting a statistical quirk because they lay outside of the orthodox paradigm. This is clearly a case where it is good to live in interesting times.

Citation: Green, R., Krause, J., Briggs, A., Maricic, T., Stenzel, U., Kircher, M., Patterson, N., Li, H., Zhai, W., Fritz, M., Hansen, N., Durand, E., Malaspinas, A., Jensen, J., Marques-Bonet, T., Alkan, C., Prufer, K., Meyer, M., Burbano, H., Good, J., Schultz, R., Aximu-Petri, A., Butthof, A., Hober, B., Hoffner, B., Siegemund, M., Weihmann, A., Nusbaum, C., Lander, E., Russ, C., Novod, N., Affourtit, J., Egholm, M., Verna, C., Rudan, P., Brajkovic, D., Kucan, Z., Gusic, I., Doronichev, V., Golovanova, L., Lalueza-Fox, C., de la Rasilla, M., Fortea, J., Rosas, A., Schmitz, R., Johnson, P., Eichler, E., Falush, D., Birney, E., Mullikin, J., Slatkin, M., Nielsen, R., Kelso, J., Lachmann, M., Reich, D., & Paabo, S. (2010). A Draft Sequence of the Neandertal Genome Science, 328 (5979), 710-722 DOI: 10.1126/science.1188021

Latest POI is Up: “Elaine Howard Ecklund–How Religious Are Scientists?” | The Intersection

The show website is here; you can listen here and download/subscribe here. Here is the description of the program:
It’s hard to think of an issue more contentious these days than the relationship between faith and science. If you have any doubt, just flip over to the science blogosphere: You’ll see the argument everywhere.
In the scholarly arena, meanwhile, the topic has been approached from a number of angles: by historians of science, for example, and philosophers. However, relatively little data from the social sciences has been available concerning what today’s scientists actually think about faith.
Today’s Point of Inquiry guest, sociologist Dr. Elaine Ecklund of Rice University, is changing that. Over the past four years, she has undertaken a massive survey of the religious beliefs of elite American scientists at 21 top universities. It’s all reported in her new book Science vs. Religion: What Scientists Really Think.
Ecklund’s findings are pretty surprising. The scientists in her survey are much less religious than the American public, of course—but they’re also much more religious, and more “spiritual,” than you might expect. For those interested in debating the relationship between science and religion, it seems safe to say that her new data will be hard to ignore. Once ...


Iron Man 2’s Science & Tech Are Grounded in Reality—Mostly | 80beats

Iron Man 2It’s big, it’s loud, it’s Iron Man 2, and it opens today.

Like a lot of summer blockbusters, this sequel stretches the laws of physics and the capabilities of modern technology. But, admirably, a lot of the tech in Iron Man 2 is grounded in fact.

Spoiler Alert! Read on at your own risk.

Palladium and particle colliders

Being Iron Man is killing Tony Stark. As this sequel begins, the palladium core that powers the suit and keeps Stark alive is raising toxicity levels in his bloodstream to alarming highs. It’s not hard to see why Iron Man would try palladium—the now-infamous cold fusion experiments that created a storm of hype in 1989 relied on the metal. And it’s true that palladium does have some toxicity, though it’s been used in alloys for dentistry and jewelry-making.

Having exhausted the known elements in the search for a better power source, Stark, ever the DIY enthusiast, builds a particle collider in his workshop. This is actually not crazy: Physicist Todd Satogata of Brookhaven National Lab says you can build tiny particle colliders; even whiz-kid teenagers do it.

Powering the accelerator, however, might be an issue. 2.5 miles long, Brookhaven’s superconducting collider needs 10 to 15 megawatts of power—enough for 10,000 or 15,000 homes. “For Stark to run his accelerator, he’s gotta make a deal with his power company or he’s gotta have some sort of serious power plant in his backyard,” Satogata says [Popular Mechanics].

In addition, Stark doesn’t appear to have the magnets needed to focus a beam as tightly as he does in the film, where it shreds his shop before he gets it focused in the right place. And, as we covered with the recent discovery of element 117, the ultra-heavy lab-created elements that Stark could have created in his accelerator don’t last long. However, back in 1994 when only 106 elements dotted the periodic table, DISCOVER discussed the idea some physicists have of an “island of stability” where elements we’ve yet to discover/create might be able to exist in a stable way. Perhaps Tony found it.

The guts of the suit

After a long quest, the U.S. military gets its hands on Stark’s most magnificent piece of technology, the Iron Man suit. What they saw when they looked inside was the work of special effect wiz Clark Schaffer.

The silvery suit, originally seen in the first “Iron Man,” is shown again in the new movie in an “autopsy” scene in which the government begins tearing it apart to see how it works. “[The filmmakers] wanted it to look like what you see under the skin of a jet,” said Schaffer, who, along with friend and modeler Randy Cooper, worked on the suit in Los Angeles for six weeks. “There’s an aesthetic to it. I try to make it look as functional and practical as possible but also something that has beauty to it. That was my baby” [Salt Lake Tribune].

But how might the Iron Man suit be able to stand up to the punishment Stark continually receives? Tech News Daily proposes that he took advantage of something scientists are developing now: carbon nanotube foam with great cushioning power.

Plasma weaponry

Iron Man’s nemesis in this second installment is Ivan Vanko, played by the villainous and murky Mickey Rourke, who you might have seen in previews stalking around a racetrack with seemingly electrified prostheses attached to his arms. The explanation in the film is hand-waved a bit, but it seems Vanko’s weapons rely on plasma.

Scientists actually are developing weapons based on plasma, such as the StunStrike, which essentially fires a bolt of lightning, creating an electrical charge through a stream of plasma. Researchers have recently even created what appears to be ball lightning in microwave ovens, which Iron Man’s “repulsor blasts” resemble [Tech News Daily].

Drones and hacking

Vanko isn’t happy with just amazing plasma tentacles, though. Working for Stark’s rival military-industrialist Justin Hammer (Sam Rockwell), he develops a horde of ghastly humanoid drones for each branch of the military. That, of course, is straight out of science fact—our military relies increasing on robots, be they unmanned aerial vehicles, bots on the ground that investigate roadside bombs, or even unmanned subs currently under development.

He’s a hacker, too, seizing control of an Iron Man suit worn by Don Cheadle as Stark sidekick James Rhodes. As DISCOVER covered in December, that’s a real-life worry, too. Hackers figured out how to steal the video feeds from our Predator drones because of an encryption lapse at one step in the process.

Related Content:
DISCOVER: 10 Obscure Elements That Are Most Important Than You’d Think (gallery)
DISCOVER: An Island of Stability
DISCOVER: Attaining Superhero Strength in Real Life, and 2 more amazing science projects
DISCOVER: The Science and the Fiction presents the best and worst use of science in sci-fi films
80beats: A Hack of the Drones: Insurgents Spy on Spy Planes with $26 Software
Bad Astronomy: Iron Man = Win


We are not a Christian nation | Bad Astronomy

I have no problems with people being religious per se. I think that people have the right to believe in whatever they want. If they happen to believe in something that is demonstrably wrong, well then, they should be prepared to suffer the slings and arrows of reality.

The problem tends to come in when some religious people try to impose their religion on others. If you go through my posts on religion, you’ll find that this is where I tend to step in. Want to teach creationism in the classroom? Uh uh. Want to oppress women? Sorry, fella. Think abstinence-only education works and you should get government grants to teach it? Keep it in your own pants, please.

ffr_jfk_religion

The problem is amplified by the fact that pretty much every religion tends to think of itself as the One True Belief. And when they get some political clout, things get very itchy indeed. Or have we already forgotten what the Taliban did to the Buddhas of Bamyan?

That’s why I worry when I hear politicians in the U.S. saying we’re a Christian nation. We’re not. We’re a nation of mostly Christians, to be sure, but there are other religions here as well, and a bunch of non-believers too.

When confronted with this, most of these politicians tend to say the Founding Fathers were Christians, and based this country on Christian beliefs. But that’s not true either: the basis of our country’s law is the Constitution, and the Founders took a great deal of care making sure it kept religion at arm’s length (despite what some politicians believe).

With the far-right going apoplectic every time someone mentions non-believers or religions other than Christianity (remember this?), I imagine the 2012 Presidential election will be one where every candidate tries to out-religious the next. But we have the 2010 midterms coming up, and it’ll be an issue there too.

That’s why I like very much what the Freedom From Religion Foundation is doing: they’ve created wonderful ads with quotes from the Founding Fathers showing precisely how they felt on this issue. The one above of JFK is cool, because his candidacy was attacked for him being a Catholic, of all things. The thing is, he was a religious man, and still understood that religion must be kept away from politics.

But far and away, I love this one the most:

ffr_adams_tripoli

Not a lot of wiggle room in that, is there? Sarah Palin, of course, disagrees (read that link; Barry Lynn’s — sorry, I mean the Reverend Barry Lynn’s — comment there is wonderful). But I suspect that her grasp of the actual history of this nation is somewhat tenuous, given her many inaccurate statements about it and about reality in general.

Anyway, these banners (seven in total) will run on buses, and it’ll be interesting to see how the far-right religious folks will react. I’ll note that the FFRF ran a full-page ad in the New York Times yesterday about how the National Day of Prayer is unconstitutional, which I agree with. Strongly.

What strikes me as funny is how the über-religious in the US fight to tear down the wall of separation, not realizing that they are weakening themselves. What stands between their religion being dominant and, say, Muslims? This is one of the many problems with having religion intertwined with government. As long as it’s your religion, hurray. But see those guys over there praying in a place of worship with slightly different architecture from yours? They feel exactly the same way about their religion as you do about yours. The only way to protect your own freedom of religion is to protect your freedom from theirs.

There are two ways to do that. You can either emulate the Taliban… or you can make sure that laws, politics, and government are kept wholly and, I dare say, fundamentally separated from religion.

The choice is ours.


Penn State’s Football Stadium: Now 50% Louder! | Discoblog

Penn State's college football team has a new trick in its playbook--courtesy of acoustical science.
Penn State graduate student Andrew Barnard's acoustic mapping research illustrates how the relocation of 20,000 student-fans in Penn State's Beaver Stadium could lead to more wins for the Nittany Lions football team.
Last year, during three homes games, Barnard recorded and measured crowd noise at the stadium using a series of strategically placed acoustic meters. He found when the Nittany Lions had the ball, the crowd noise reached 75 decibels on the field. But when the opposing team played offense, the noise climbed to 110 decibels. As a result, the visiting quarterback's calls could only be heard within about 18 inches from him.
Barnard wondered whether he could make it even tougher for visiting QBs. So when the stadium was empty, he used a loudspeaker to create noise in various seating locations and measured the sound intensity on the field. According to Gizmodo, Barnard zeroed in on the stadium's acoustical sweet spot, where the loudest fans could be the most effective against opposing teams:
When the stadium was empty, he searched for the best spots for an audible assault by carrying a noisy speaker around to 45 different seats ...


Soul Made Flesh–A Late, Late Rave! | The Loom

While perusing the latest issue of the Journal of the History of Neurosciences, I was surprised to discover a review of my book Soul Made Flesh. It’s been six years since it came out. I guess the stack by their nightstand is pretty tall!

But I certainly don’t mind the wait when it’s a review like this:

This book is a joy to read. Zimmer has crafted a pleasant style, leveraging his talents that were cultivated during his time as a newspaper journalist. The texture of the pages and the typesetting suggest an old-fashioned printing and binding for the book; it’s pleasant to handle and easy reading. Several chapters are adorned with period illustrations by Christopher Wren. For anyone interested in the birth of contemporary medicine, social philosophy, and religion, this is a wonderland of enticing history. In fact, most people interested in this period of history will find the book is an entertaining read; one that is difficult to put down.

Fortunately, the book is also still in print six years later, so you can get yourself a copy if you’re interested. Since the book looks at the birth of neurology 350 years ago, it’s not out of date!


NASA Successfully Tests Its Astronaut Capsule, But Will It Ever Be Used? | 80beats

OrionAbortTestThe Orion capsule is dead; long live the Orion capsule. Yesterday in the New Mexico desert, NASA successfully completed a test of the resurrected craft’s launch-abort system. Rockets blasting with 500,000 pounds of thrust carried it more than a mile into the sky before releasing it for a parachute-aided descent back to the Earth.

The launch-abort system is designed to pull the astronauts and the Orion capsule away from the launch pad in the event of a problem such as fire. It is also designed to catapult them away from the rocket if an emergency occurs during the climb to orbit [The Denver Post].

Orion, however, may never need this launch-abort system. The craft was originally intended to be the crew capsule in the Constellation program, riding into space atop heavy-lift rockets and ferrying astronauts back to the moon or to Mars. Like the rest of Constellation it was left out of President Obama’s January budget.

But when the President revised his plan in April he proposed re-purposing Orion as an escape vehicle for the International Space Station.

The aging US space shuttle fleet, which carries astronauts to the International Space Station, is due to be grounded at the end of the year, leaving US astronauts to hitch rides on Russian spacecraft to orbiting station until a replacement is developed.

Orion is now being considered as an escape module for the ISS so US astronauts do not have to rely on Russian craft for a return to Earth [AFP].

So even if President Obama’s plan comes to fruition, Orion still may not need this launch-abort system in its new role. However, NASA says the test’s success is still crucial for the future of space flight.

NASA personnel say elements of the abort system could find use somewhere, whether with Orion or on the privately operated rockets that Obama wants to hire to ferry astronauts to orbit after the shuttle’s phaseout [Scientific American].

Related Content:
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80beats: Neil Armstrong Slams Obama’s Space Plan; President Will Defend It Tomorrow
80beats: Obama’s NASA Plan Draws Furious Fire; The Prez Promises To Defend His Vision
80beats: Obama’s NASA Budget: So Long, Moon Missions; Hello, Private Spaceflight
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Image: NASA


Scientists Speak Out on Climate Science and Its Enemies | The Intersection

There is a powerful letter, signed by 225 National Academies members, in the latest Science. Not only does it explain why we accept the consensus of mainstream climate science (or mainstream evolutionary science, or planetary science, or cosmology), but it denounces Cuccinelli-style tactics:
We also call for an end to McCarthy- like threats of criminal prosecution against our colleagues based on innuendo and guilt by association, the harassment of scientists by politicians seeking distractions to avoid taking action, and the outright lies being spread about them. Read the whole statement. Bravo to the these scientists for taking such a stand. UPDATE: I now see that these scientists explicitly state they are not speaking on behalf of the National Academies. So I may have erroneously attributed the existence of the statement to the Academy in an earlier version of this post. It has been modified to remove this unwarranted assumption.


A Hundred Years Without A Malaria Vaccine | The Loom

mtsitunes220When I’ve traveled abroad, I’ve gotten my share of jabs for hepatitis and other diseases. But for malaria, the best I could hope for was to take malaria-blocking drugs like Lariam, which gave me weird dreams at night and made me feel as if someone was tugging my hair all day.

For people who live in countries with malaria, these prophylactic drugs just aren’t practical. Given that 800,000 people a year die of malaria, why don’t we have a good vaccine for it? It’s not for lack of trying–in fact, this year marks the 100th anniversary of the first attempts to make a malaria vaccine.

To understand this epic fail, I talked on my latest podcast with Irwin Sherman, a malaria expert and author of The Elusive Malaria Vaccine: Miracle or Mirage?.

Check it out.


Whales evolved from small aquatic hoofed ancestors | Not Exactly Rocket Science

This article is reposted from the old WordPress incarnation of Not Exactly Rocket Science.

Travel back in time to about 50 million years ago and you might catch a glimpse of a small, unassuming animal walking on slender legs tipped with hooves, by the rivers of southern Asia. It feeds on land but when it picks up signs of danger, it readily takes to the water and wades to safety.

Indohyus

The animal is called Indohyus (literally “India’s pig”) and though it may not look like it, it is the earliest known relative of today’s whales and dolphins. Known mostly through a few fossil teeth, a more complete skeleton was described for the first time last week by Hans Thewissen and colleagues from the Northeastern Ohio Universities. It shows what the missing link between whales and their deer-like ancestors might have looked like and how it probably behaved.Whales look so unlike other mammals that it’s hard to imagine the type of creature that they evolved from. Once they took to the water, their evolutionary journey is fairly clear. A series of incredible fossils have documented their transformation into the masterful swimmers of today’s oceans from early four-legged forms like Pakicetus and Ambulocetus (also discovered by Thewissen). But what did their ancestors look like when they still lived on land?

Hooves to flippers

Until now, we had little idea and their modern relatives have provided few clues. According to molecular evidence, the closest living relatives of whales are, quite surprisingly, the artiodactyls, a group of hoofed mammals that includes deer, cows, sheep, pigs, giraffes, camels and hippos.

They all have a characteristic even number of toes on each hoof and not a single one of them bears even a passing resemblance to whales and dolphins. Among the group, the hippos are evolutionarily closest and while they are at least at home in water, their family originated some 35 million years after the first whales and dolphins did.

Enter Indohyus, a small animal about 70cm long that lived 47 million years ago. It was a member of a family of mammals called the raoellids, prehistoric artiodactyls that lived at the same time as the earliest whales and hailed from the same place of origin – southern Asia. By analysing a fossilised skull and limbs collected from India, Thewissen found compelling evidence that the raoellids were a sister group to the ancestors of whales.

Even though Indohyus had the elegant legs of a small deer and walked around on hooves, it also had features found only in modern and fossil whales. Its jaws and teeth were similar to those of early whales, but the best evidence was the presence of a thickened knob of bone in its middle ear, called an involucrum. This structure helps modern whales to hear underwater, it’s only found in whales and their ancestors, and acts as a diagnostic feature for the group.

Based on these physical similarities, Thewissen suggests that the raoellids are a sister group to the whales. Both of these groups are evolutionary cousins to all modern artiodactyls. (As a note for journalists and creationists, Indohyus is not a direct ancestor of whales, as many news sites are claiming, and nor did whales ‘evolve from deer’!)

A swimming Indohyus

Life in the water

Indohyus‘s skeleton also suggests that it was partially adapted for life in the water. Its leg bones were unusually thick, a feature shared by other aquatic animals including hippos, sea otters and manatees. These heavier bones stop swimming mammals from floating by default and allow them to hang in the water and dive more easily.

Because Indohyus had slender legs and not paddle-shaped ones, Thewissen pictures it wading in shallow water, walking hippo-style along the river floor while its heavy bones provided ballast.

Thewissen found more clues about the animal’s lifestyle from its teeth, and particularly the levels of certain isotopes in their enamel. Levels of oxygen isotopes matched those of water-going mammals, providing further support for Indohyus‘s aquatic tendencies. Its large crushing molars are typical of plant-eaters and levels of carbon isotopes in them suggested that Indohyus either came onto land to graze (like hippos) or fed on plants and invertebrates in the water (like muskrats). In terms of behaviour, they were close to the modern mousedeer, a tiny, secretive deer that feeds on land but flees into streams when danger threatens.

Put together, this portrait of Indohyus‘s life also tells us about the changes that drove the evolution of whales, and it looks like it wasn’t a move to water. Whales and raoellids are evolutionary sisters and since early members of both groups were happy in the water, aquatic lifestyles must have pre-dated the origin of whales.

Instead, Thewissen suggests that the key step was a switch in diet. He speculates that whales developed from an Indohyus-like ancestor that fed on plants and possibly small invertebrates on land, but fled to water to escape predators. Over time, they slowly turned into meat-eaters and evolved to swim after nimble aquatic prey.

Video: Have a look at Thewissen talking about Indohyus and the origin of whales.

Images of Indohyus are painted by the extraordinary Carl Buell

Reference: Thewissen, J.G., Cooper, L.N., Clementz, M.T., Bajpai, S., Tiwari, B.N. (2007). Whales originated from aquatic artiodactyls in the Eocene epoch of India. Nature, 450(7173), 1190-1194. DOI: 10.1038/nature06343

Dramatic image of Eyjafjallajökull ash cloud | Bad Astronomy

Some volcanoes just don’t know when to stop. Like Eyjafjallajökull:

terra_Eyjafjallajokull

[Click to envulcanate.]

This image is from NASA’s Terra satellite, and was taken on May 6 (yesterday). The border of Iceland is outlined, and you can see the ash plume carries on for hundreds of kilometers. Air travel is being grounded yet again.

Interestingly, according to the NASA site, volcanoes this far north don’t affect global climate much. Air currents rise at low to mid-latitudes, and sink in the high latitudes, so the aerosol particles that can cool the atmosphere (like sulfur dioxide) don’t get spread globally in eruptions like this one. But the ash particles do make it to Europe, causing havoc there.


No scientists had to die for this paradigm shift! | Gene Expression

In Science Ann Gibbons has a very long reported piece, Close Encounters of the Prehistoric Kind. It’s well worth reading, but behind a pay wall. If you don’t have access though, I want to spotlight one particular section:

The discovery of interbreeding in the nuclear genome surprised the team members. Neandertals did coexist with modern humans in Europe from 30,000 to 45,000 years ago, and perhaps in the Middle East as early as 80,000 years ago (see map, p. 681). But there was no sign of admixture in the complete Neandertal mitochondrial (mtDNA) genome or in earlier studies of other gene lineages…And many researchers had decided that there was no interbreeding that led to viable offspring. “We started with a very strong bias against mixture,” says co-author David Reich of Harvard Medical School in Boston. Indeed, when Pääbo first learned that the Neandertal DNA tended to be more similar to European DNA than to African DNA, he thought, “Ah, it’s probably just a statistical fluke.” When the link persisted, he thought it was a bias in the data. So the researchers used different methods in different labs to confirm the result. “I feel confident now because three different ways of analyzing the data all come to this conclusion of admixture,” says Pääbo.

The finding of interbreeding refutes the narrowest form of a long-standing model that predicts that all living humans can trace their ancestry back to a small African population that expanded and completely replaced archaic human species without any interbreeding. “It’s not a pure Out-of-Africa replacement model—2% interbreeding is not trivial,” says paleoanthropologist Chris Stringer of the Natural History Museum in London, one of the chief architects of a similar model. But it’s not wholesale mixing, either: “This isn’t like trading wives from cave to cave; the amount of admixture is tiny,” says molecular anthropologist Todd Disotell of New York University in New York City. “It’s replacement with leakage.”

The power of data to overwhelm human prejudice is sometimes very awesome. And the bias which Reich and Pääbo exhibited was not unfounded; Pääbo was involved in the sequencing of the Neandertal mtDNA, and found no evidence of admixture there. These data were strong, and I believe they should now shift our assessment of probabilities in relation to earlier papers which claimed some admixture between the population which derives from the Out-of-Africa expansion, and the Others.

In the second section it is notable that Chris Stringer has discarded replacement as not viable. He uses the term “not trivial,” which means that it’s a significant finding of note which one can’t simply ignore when generating inferences from a set of facts which one takes as axiomatic. Disotell’s attempt to minimize the finding is more a matter of rhetoric. He does not dismiss the admixture, he simply consigns it to the undefined category “tiny.” To some extent this reminds me of the neutralist vs. selectionist arguments of the 1970s, and more recently of the Out-of-Africa vs. Multi-regionalism disputes in human evolutionary origins. An argument over the meaning of words is a matter of law, an argument grounded in empirical data and quantitative estimates is an argument about science. No one holds to the extreme caricatures of any four of the models at this point; we’ve established that all these paradigms are unchaste, now we’re just haggling over price. We know that humans and the Others did the deed, we’re now mapping out the what, where, and how often.

But this is not the closing of the gate of itjihad. Dienekes presents an alternative model which may explain the data:

There is an alternative explanation. It involves the emergence of Homo sapiens and Homo neanderthalensis from a common ancestor and the subsequent admixture of Homo sapiens with populations that have branched out before this divergence. This would account for increased similarity between Eurasians and Neandertals, but without the problem of explaining how “Neandertal” ancestry is so similar in Europeans and East Asians.

What about Africans? Why do they stand further away from Neandertals? The answer is simple: low-level of admixture with archaic humans in Africa itself. It is fairly clear to me that the sapiens line whose earliest examples are in East/South Africa must have been an offshoot of an older African set of populations. We are lucky that Neandertals lived in a climate conducive to bone (or even DNA) preservation, while the African populations inhabiting the tropics left no traces of their existence.

In conclusion: I am not at all convinced that the authors have uncovered evidence of Neanderthal admixture in Eurasians; the alternative explanation is that modern humans and Neandertals were related, modern humans spread from East Africa/West Asia and as they entered deeper into Africa, they interacted with archaic human populations there.

In his magisterial post John Hawks has hinted at more wheels within wheels. From a Kate Wong story in Scientific American:

Intermixing does not surprise paleoanthropologists who have long argued on the basis of fossils that archaic humans, such as the Neandertals in Eurasia and Homo erectus in East Asia, mated with early moderns and can be counted among our ancestors—the so-called multiregional evolution theory of modern human origins. The detection of Neandertal DNA in present-day people thus comes as welcome news to these scientists. “It is important evidence for multiregional evolution,” comments Milford H. Wolpoff of the University of Michigan, the leading proponent of the theory.

The new finding shows that “gene flow across taxonomic boundaries happens,” observes geneticist Michael F. Hammer of the University of Arizona. Hammer is among the minority of geneticists who have espoused the idea of gene flow between archaic and modern populations. His own studies of the DNA of people living today have uncovered, for example, a stretch of DNA that seems to have come from encounters between moderns and H. erectus.

I assume Wolpoff is exultant. I do not personally think that this finding necessarily is going to result in a renaissance in Multi-regionalism, but Wolpoff has been the subject of a rising tide of skepticism and dismissal these past few decades. But rather than a more robust discussion between a revived Multi-regionaism and Out-of-Africa, I think these findings, and those that are likely to follow, will force us to move past simplistic typologies and accept that human evolutionary history works itself out through the principles of population genetics, and so can only roughly be modeled in words. The devil is in the parameters.

Washington Post Editorial Page Condemns Cuccinelli | The Intersection

Here it is. It's damning, and the most powerful statement yet:
We hope that Gov. Robert F. McDonnell (R) and the University of Virginia have the spine to repudiate Mr. Cuccinelli's abuse of the legal code. If they do not, the quality of Virginia's universities will suffer for years to come. Importantly, the Post makes the point that there is no serious evidence to justify the inquiry. You would have to have good reasons for suspecting Mann of fraud; merely disagreeing with his results certainly doesn't suffice. But there is no good reason for suspecting Mann of fraud--misreading emails and taking them out of context does not constitute any such thing. Every inquiry that has looked closely and seriously into ClimateGate has found that there's no there there. Or as the Post recaps:
For Mr. Cuccinelli's "investigation" to have any merit, the attorney general must suppose that Mr. Mann "knowingly" presented "a false or fraudulent claim for payment or approval." Mr. Cuccinelli's justification for this suspicion seems to be a series of e-mails that surfaced last year in which Mr. Mann wrote of a "trick" he used in one of his analyses, a term that referred to a method of presenting data to non-experts, ...


Griffin: Obama Space Policy = Drivel

Former NASA chief calls Obama space policy proposals "drivel", Examiner.com

"Former NASA administrator Michael Griffin takes strong exception to most of President Obama's proposed space exploration policy, disagreeing with the major points and calling much of it "drivel." Griffin spoke in Seattle Tuesday evening at the Museum of Flight. .. Griffin also rapped the President's proposal to nix Moon missions, and concentrate on heavy lifting and Mars. "There was considerable other drivel in the president's proposals, which were supposedly based on the Augustine Commission," he said."

Moon Walkers Briefed On Internal NASA Study Results

Keith's note: ESMD AA Doug Cooke briefed Neil Armstrong and Gene Cernan today via telecon on the results of NASA's internal exploration working group studies. No word yet as to when the rest of us will learn what Doug told Armstrong and Cernan - perhaps next week a this Senate hearing on 12 May?

Reshaped spaceflight plan gains support, MSNBC

"Nelson has arranged a high-profile Senate hearing on the future of U.S. human spaceflight for May 12, just two days before the shuttle Atlantis is scheduled to lift off on its final trip to the International Space Station. Among those who may testify are Apollo astronauts Neil Armstrong and Gene Cernan, the first man and the last man to walk on the moon."

Presentations From The Closed Space Organization Meeting (Update)

NASA Presentations on New Space Plans for FY2011, Planetary Defense

"Lori Garver, Ed Weiler, Bobby Braun, and Laurie Leshin (all from NASA) presented at a meeting in Washington, D.C. on 05 May 2010 aspects of the new NASA plan, specifically those elements involved with the new NASA budget. I have posted these docs to the Google Docs library (General) for this site."

Keith's note: The Google Docs server where these presentations were originally posted does not seem to be cooperating, so A.C. Charania has provided me with copies of the presentations - here they are: Robert Braun,
Laurie Leshin, and Ed Weiler

Google Goggles Turns Translator

From Geeks are Sexy Technology News:

Those of us not lucky/smart enough to read foreign languages have, until now, been fairly poorly served by technical replacements to the trusty travel phrase book.There are, of course, plenty of standalone handheld devices which are simply elect

Genetic Switch Could Restore Memory

From Wired Top Stories:

Scientists have discovered what could be a key to why older mice, and possibly older people, lose their memory. The research suggests that the genetic changes responsible could be reversed.

Read the whole article