Author: Discover Main Feed

John Hawks has a post up, Multiregional evolution lives!, in response to Rex Dalton’s reporting on Neandertal-human admixture. He notes:

These ongoing studies are concluding that present-day genetic variation is inconsistent with a simple model where a random-mating ancestral population gives rise to today’s global population by means of a staged out-of-Africa dispersal. They next look at a model with some substantial (possibly complete) isolation between ancient human populations followed by a subsequent out-of-Africa dispersal. They show that this model fits the data significantly better.
So far, so good.

For a moment, I’m going to adopt a critical perspective. Previous results haven’t yet been able to answer an important possible question: Can they distinguish the effects of intermixture outside Africa from an ancient population structure inside Africa? Increasingly it looks like population structure inside Africa may have been very important to the evolution of Late Pleistocene Africans. How can we distinguish these kinds of structure from each other?

The short answer is that maybe we can’t, yet. Human population history was not simple. If we take a simple model and add more parameters, it will fit the data better. The question is whether there may be some even better model with the same number of parameters. Population structure within Africa, selection on some loci but not others, asymmetrical migration — all these and more might be possible.

The Out of Africa + total replacement model had a clean elegance, but it might not be viable in the near future. That being said it seems to me that the old Multiregional model implied, though proponents were often careful to reject this characterization, more regional parity than was the case. I do not expect the predominant African ancestry of modern humans to be rejected for example. There are other frameworks out there, such as Alan Templeton’s Out of Africa again and again (Richard Dawkins favors this in The Ancestor’s Tale).

Muslim Group Says It Is Warning, Not Threatening, ‘South Park’ Creators. Here’s a screen shot from the cached version of the site (it was hacked after the threat):

The website is run by a dozen crazy people. No word on crazy Buddhists objecting to the fact that Buddha was depicted as a cocaine snorting junkie in the episode. It’s a two part episode, so watch the finale tonight.

In my lastest podcast, I talk to Keith Klugman of Emory University about pneumonia–how its devastation worldwide is worse than we once thought, and how vaccines are proving surprisingly effective at keeping it in check. A pneumonia vaccine may even prevent a replay of the 50 million deaths during the 1918 Spanish flu pandemic. Check it out.

In today’s edition of far-out science, researchers have found evidence that the wafting aroma of food has an effect on an organism’s lifespan–and they’ve demonstrated that interfering with a fruit fly’s sense of smell causes it to live a longer, healthier life. While there’s no guarantee that the trick would work for humans, optimistic researchers suggest that certain odors—or drugs that block us from sensing them—might one day help prevent disease and extend lives [ScienceNOW].

In the past decade, scientists have established a clear connection between extremely low-calorie diets and extended lifespans; studies have demonstrated that yeast, fruit flies, mice, and monkeys on these diets live longer than their peers. While the exact mechanism at work isn’t yet clear, researchers suspect that a near-starvation diet causes an organism’s metabolism to slow down, and triggers other changes that evolved to help organisms survive in times when food was scarce. Now scientists say it may not be just what a creature eats, but also what it smells that has an effect on how long it lives.

In one 2007 study, molecular biologist Scott Pletcher and his colleagues found that completely eliminating fruit flies’ sense of smell caused them to live nearly 20 percent longer than normal flies. They also found that wafting the smell of yeast, a tasty treat for fruit flies, towards flies that were on a low-cal, live-extending diet hastened the death of those flies. This led the scientist to hypothesize that specific odors might be influencing the flies’ lifespans. Luckily, other scientists had identified a receptor in a group of neurons that enable fruit flies to smell carbon dioxide, which signals the presence of a good meal of tasty yeast [ScienceNOW]. So, Pletcher and his team set out to find if the CO2 had anything to do with the duration of the flies’ lives.

For the new study published in PloS Biology, Pletcher eliminated the fruit flies’ ability to smell carbon dioxide, while keeping the rest of the olfactory system intact. Even on a standard, full-calorie diet, the flies that couldn’t detect CO2 lived up to 30 percent longer than other flies. The researchers suggest that the absense of CO2 may have indicated to the altered flies that food was scarce in the environment, prompting them to snap into survival mode. Oddly, however, the life-extending effect was only seen in female flies–male flies gained no such benefit. The smell-deprived female flies also seemed healthier and stronger by several measures: They stored extra fat, produced more offspring, and proved to be more resistant to oxidative stress than normal flies.

Pletcher isn’t sure how the inability to smell CO2 extended the females’ lifespans, but he says the findings open up fascinating new areas for studies of human aging. He suggests that there might be certain smells or drugs that would block certain odors, and which could give humans a bit more time before we shuffle off our mortal coils. Matt Karberlein, an aging expert who wasn’t involved in Pletcher’s research, was cautiously optimistic about that possibility, saying: “We definitely undergo physiological changes in response to smelling food – I’m getting hungry just thinking about it – so I think it’s possible” [New Scientist].

Related Content:
80beats: A Single Genetic Tweak Gives Mice Longer, Healthier Lives
80beats: Low-Calorie Diet Staves off Aging & Death in Monkeys
Not Exactly Rocket Science: Low-calorie diets improve memory in old age
DISCOVER: In Worms, a New Theory on Aging

Image: Scott Pletcher / University of Michigan, Ann Arbor

New technique shows hearbeat-like “drumming” in atoms in graphite and may one day let us see reactions in living cells

My friend Sara Mayhew is pretty cool. I am reminded of this by her interview on Skepticality this week, and I’ve been meaning to write about her again anyway.

How do I know she’s so cool? I mean, besides this being my blog which makes me the final arbiter of cool? And also that she linked to me in a fabulous cartoon she drew?

She’s cool because she’s a skeptic and she draws manga and she’s a TED fellow. And she’s also pretty frakkin’ smart. And she spreads the joy of science and skepticism through her art. Behold:

That, me droogs, is a very cool ad. And how can you not love someone who asks, “Do we have the courage to let go of our beliefs, to grab on to what is true?”

If you want more of her, then check out the talk she gave at CfI LA in March, and you too will see why I like her so much.

So I’ve given you the website of the Kennedy School science blogging event–cosponsored by the Knight Science Journalism Fellowships program–but not yet the speakers list. Here goes:
Program 9:30 Introduction/Framing Sheila Jasanoff, STS Program, Harvard Kennedy School 10:00-11:00 Panel 1: Blogging as Business Henry Donahue (CEO, Discover), Gideon Gill (Science Editor, Boston Globe), Representative of Seed Magazine [not confirmed] 11:15-12:15 Panel 2: Science on the Web Francesca Grifo (Union of Concerned Scientists), Chris Mooney (MIT and Discover), Jessica Palmer (Bioephemera) 1:15-2:30 Panel 3: Rules and Responsibility Amanda Gefter (New Scientist), Kimberly Isbell (Citizens Media Law Project), “Dr. Isis” (ScienceBlogs.com), Thomas Levenson (MIT) 2:30-3:30 Panel 4: Norms and Law Sam Bayard (Citizen Media Law Project), Phil Hilts (Knight Program, MIT), Cristine Russell (Harvard Kennedy School) 3:30-4:00 Open Discussion and Wrap-Up Incidentally, I also want to credit the poster artist whose work is helping so much to publicize this event: Alex Wellerstein. Amazing work.

The F/A-18 Super Hornet burns through more fuel than any other aircraft in the Unites States Navy, whose pilots have flown more than 400 of the jets. But with the week of Earth Day upon us, the Navy is trying to use the jet to show it can mend its fuel-guzzling ways. Tomorrow the “Green Hornet,” an F/A-18 running on a half-petroleum, half-biofuel blend, will make a test flight from Maryland.

Secretary of the Navy Ray Mabus has set a target that half of naval energy consumption will come from alternative sources by 2020. A “Great Green Fleet,” to sail by 2016, will include nuclear ships, as well as surface combatants with hybrid electric power systems using biofuel and biofuel-powered aircraft [National Geographic]. Before we can talk about ambitious deployment targets, however, the Navy has to prove that its “green” fighter has got what it takes, and so the experimental F/A-18 will try to break the sound barrier.

The Green Hornet’s biofuel constituent is made from Camelina sativa, also called gold-of-pleasure or false flax. (It earned the latter moniker for surviving by looking increasingly like real flax, a talent that garnered it a spot in our gallery of plant and animal impostors.) As a biofuel, Camelina has the advantage of growing with little energy input. Humans have cultivated the plant for millennia; the Romans used its oil in lamps and in cooking (pdf). Another advantage is that the fuel made from it was remarkably similar to the military petroleum jet fuel called JP-5 [National Geographic]. However, just as ordinary car engines can’t run on strictly ethanol, the design of the engine seals on the F/A-18 still demand a substantial component of conventional fuel.

Even advanced biofuels have their detractors among environmentalists and energy gurus, but the military’s potential embrace of them and other technologies—like electric vehicles, solar, and wind power—could supply the marketplace boost they need. The size of the military’s investment will create economies of scale that help bring down the costs of renewable energy, and military innovations in energy technologies could spread to civilian uses, just as the Internet did [Miami Herald].

And perhaps when you go to an air show in a decade, the Blue Angels‘ F/A-18s will be flying on biofuel.

Related Links:
80beats: London’s Garbage Will Soon Fuel Some British Airways Flights
80beats: Air New Zealand Tests Jet Fuel Made From Poisonous Jatropha Seeds
80beats: Super-Green, Algae-Derived Jet Fuel Passes Tests With Flying Colors
80beats: DARPA Wants a Biofuel Jet, While Germany Works on a Hydrogen Plane
DISCOVER: Impostors! Ten Species That Survive By Imitation (photo gallery)
DISCOVER: The Second Coming of Biofuels
DISCOVER: It’s a Bird, It’s a Plane, on flying in formation to save fuel

Image: Staff Sgt. Aaron Allmon, U.S. Air Force

We’ve all seen this scene being played out in the local park: When a guy walks a cute dog, people don’t hesitate to approach him to strike up a conversation about schnauzer breeds. Or there’s the guy-with-a-baby scenario, in which the baby-hauling dad is perceived as friendly and non-threatening (not to mention irresistible to some women).

Now, new research from France suggests that male Barbary macaques may be onto the same “baby effect” strategy. The study found that male macaques with an infant were more likely to make male monkey buddies, as the presence of a tiny, defenseless baby immediately breaks down barriers.

The study, which is due to be published in the journal Animal Behavior, is also the first to demonstrate that infants can serve as social tools for some primates, writes Discovery News.

Study coauthor Julia Fischer told Discovery News that when a male Barbary macaque comes across another male with a baby, it sets off a “bizarre ritual.”

Fischer said the males “sit together, embrace each other, then they hold up the infant and nuzzle it. Their teeth chatter and lip smack while making low frequency grumbling noises.”

The researchers found that the monkeys with babies not only attracted other males for this ritual, they also ended up with quite a few pals this way–which had benefits for these monkeys’ social status. Discovery News writes:

Males who worked their networks in such a way tended to rise up the monkey social ladder. For example, one male rose from fifth to second place after acquiring “the highest number of male partners.”

What if a social-climbing monkey doesn’t have his own kid? No problem. The study showed that monkeys sometimes borrow babies, and proceed to use the infants as friend magnets. But it’s not all fun and games for the bambino-carrying monkeys. The researchers found that, much like human males, the male monkeys got stressed out when the kids started bawling.

Related Content:
80beats: Maternal Monkey Love: Macaque Moms Coo Over Their Babies
80beats: Monkey See, Monkey Do: How to Make Monkey Friends
80beats: Do Tricky Monkeys Lie to Their Companions to Snag More Bananas?
80beats: When Baby Monkeys Throw Public Temper Tantrums, Moms Often Give In
80beats: Female Monkeys Chat More Than Males to Maintain Social Ties

Image: Andreas Ploss

It’s not just that some birds can use tools, as primates can. Their smarts stretch even further: New research this week suggests that New Caledonian crows can solve a three-step problem, in which the three steps must be completed in succession to reach a tasty snack. Alex Taylor and colleagues document this discovery in the Proceedings of the Royal Society B.

Here’s the setup: There’s a short stick dangling from the bird’s perch on a string. That short stick isn’t long enough to grab the food that’s tucked inside a long and narrow box, but there’s a longer stick in a separate box. If the birds could figure out the first two steps—grabbing the short stick, and using it to get the longer stick—then voila, they could use the longer stick to reach the food.

The team split the birds into two groups. The birds in group number one got to mess around with each step of the process individually before researchers presented them with the problem as a whole. Coauthor Russell Gray says, “All these birds had to do was to put together things they could already do in the right sequence” [BBC News]. And they did: Each solved the problem on its first try.

Group two faced a tougher task, Taylor says. “These crows had never pulled up a tool on a string before and they had never used one tool to get another tool,” he says. Instead, he says, they used their previous experiences of pulling up a string and using a long tool to get food to innovate a new behaviour [Australian Broadcasting Corporation]. Thus, it took the group two birds a little longer to crack the puzzle—sometimes multiple attempts. But in the end they all succeeded as well. In the video above, a bird named Sam figures it out.

The genius of crows comes as no surprise. A feature article in DISCOVER’s March issue, “Who You Callin’ ‘Bird Brain?‘,” documented the mind-blowing mental abilities of crows and other members of the corvid family. For example, British researcher Nicky Clayton’s scrub jays appeared to sense when they were being watched by competitors, and thus would return to their hidden caches of food and move them around in an attempt to thwart would-be thieves.

The researchers in the three-tool study have already seen New Caledonian crows whittle branches into tools, and a stream of other finds has shown that birds recognize themselves in the mirror, or, in a confirmation of an Aesop fable, use rocks to raise water level. The American preacher Henry Ward Beecher said that if men “bore black feathers, few would be clever enough to be crows”. Certainly, in a parliament of fowls, they would rule any roost [The Guardian].

Related Content:
DISCOVER: Who You Callin’ “Bird Brain”?
DISCOVER: Magpies Recognize Themselves in the Mirror
80beats: Not So Bird-Brained After All: Rooks Make And Use Tools
80beats: Mockingbird to Annoying Human: “Hey, I Know You”
80beats: Aesop Was Right! Birds Use Rocks To Raise Water Level

Video: Taylor et. al. / Proceedings of the Royal Society B

Thierry Legault is a French amateur astronomer… and if ever the word “amateur” were misleading, it’s here. Thierry is an incredibly accomplished astronomer; his pictures have graced my blog many times in the past. Like when he caught the Shuttle and Hubble silhouetted against the Sun, or this lighthearted picture of someone painting the Sun, or the Shuttle and the space station transiting the Sun.

Come to think of it, he seems to have a fetish with the Sun. But that’s good, because he’s done it again: he’s captured a record-breaking picture of the newest new Moon!

It’s very hard to see, so I bracketed it with those red lines. Thierry caught the Moon when it was as absolutely close to the Sun as it could get at the time, so in fact this is the youngest Moon it could possibly be!

So what does that mean?

Hopefully this terrible diagram I slapped together may help. Picture yourself on the Earth (that should be easy) marked by the E in the drawing. Once a day it appears that the Sun (yellow circle) circles the Earth (black path). The Moon (crescent symbol) circles the Earth once per month — well, it rises and sets every night, but relative to the Sun the Moon moves slowly across the sky. The Moon’s distance to the Sun changes so that at sunset every night, the Moon is in a noticeably different part of the sky than it was the night before.

New Moon is when the Moon and Sun are as close together as they can be, and it happens once per month or so. But since the Moon’s orbit is tilted, it doesn’t always pass directly in front of the Sun (creating a solar eclipse); it misses by a bit. But still, the Moon is so close to the Sun in the sky that we’re basically seeing the half of the Moon that’s unlit (the lit half is facing away from us, toward the Sun). When it’s offset a bit from the Sun, only the barest, slimmest bit of it is lit that we can see, producing an extremely emaciated crescent.

When you go outside and first notice the crescent Moon with your eye, it’s usually been a day or two since it passed its closest point to the Sun. The crescent is thicker, making it easier to see, and it’s farther from the Sun than at the exact moment of New Moon, reducing the glare. The closer the Moon is to the Sun, the thinner the crescent and the brighter the sky, making it doubly harder to catch. In Thierry’s case, he caught it when it was only 4.6 degrees from the Sun — only about 9 times the diameter of the Moon itself!

That’s why astronomers prize seeing the thinnest possible crescent; it’s a contest, like anglers catching the biggest fish or bird watchers seeing a rare species. It shows that the person involved has used a lot of skill and experience… and clearly Thierry has those!

This picture shows just how difficult Theirry’s setup had to be. Look how close to the Sun he was shooting! The screen blocks a lot of the glare from the sky, and the circular hole lets the ’scope see the Moon while cutting back on glare a little more. To reduce the sky brightness further he used an infrared filter; the sky doesn’t emit as much infrared light, so it appears a little bit darker, while the Moon does reflect IR (from the Sun), making it easier to spot. He used a filter that let through light at a wavelength at 0.85 microns, just a hair outside what the human eye is sensitive to.

Of course, he couldn’t see the Moon with his eye. So he aligned the telescope with the stars the night before to get it properly tracking the sky, and then used a computer program to aim the telescope at the position of the Moon. And obviously, it worked!

This was an amazing feat. And the only way to beat it is to catch the Moon at exactly that closest solar approach when the distance is actually smaller (or, if you like, closer to the point where the two paths of objects intersects on the sky). That’ll make this observation even harder… but I suspect Thierry’s already planning his next attempt.

Well now I can expand on yesterday’s teaser. Here’s the website for the conference. Note, it requires members of the interested public to register in order to attend. Meanwhile, here’s the abstract of what we’re going to be considering–which, I might add, is not being considered nearly enough:
The blogosphere represents a new kind of deliberative space that is both enlarging and constraining public discourse in unprecedented ways. The key factor about this space, the issue this workshop seeks to explore, is its lack of norms. It is an unruly space in the sense that there are no rules of entry, access, or conduct, except for extreme forms of behavior that are positively illegal. The consequences of this unruliness have been specially severe for scientific communication, which depends on common standards of truth-telling and civility for its progress. In turn, the erosion of scientific standards destabilizes the foundations of democratic deliberation. Can norms of discourse be inserted into the blogosphere that would advance science and democracy? Can blogs induce deliberation or must they encourage extremism and rage to the detriment of public reason? Is science helped or hurt by the new media? What particular distorting factors enter the picture as blogging becomes …

For some animals, sex involves the ultimate sacrifice. Some species of spider, for example, redefine the concept of a dangerous liaison when the female turns around and devours her mate in a post-coital attack of the munchies. For males, it’s important that this act of sexual cannibalism isn’t in vain and that they die while impregnating the best possible mate. And for the wasp spider Argiope bruennichi, that means no sisters allowed.

Klaas Welke and Jutta Schneider from Hamburg’s Zoological Institute found that male wasp spiders are more likely to succumb to their grisly fate if they have just mated with an unrelated female than a sibling. Doing so allows them to avoid the heavy costs of inbreeding, where two copies of the same harmful or faulty genes have a high chance of ending up in the same individual. That’s bad news and both sexes do their best to avoid it, but for these spiders, the female holds all the cards.

She can mate with multiple partners and she can even control whose sperm actually fertilises her eggs. So the male must do everything he can in order to ensure that his genes pass on to the next generation. His job is even more difficult because he can only ever mate twice in his life. He has a pair of sexual organs – pedipalps – and each has only one use. And of course, his mate invariably attacks him after sex with murderous intent. Around 80% of sexual encounters end with the male becoming a meal and even if he survives his first time, the second time will kill him.

The male’s chances of living to mate again depend entirely on how long he lasts during his virgin encounter. If he jumps off the female within the first five seconds, he has a shot at survival. If he hangs around for more than ten seconds, he will almost certainly die. The trouble is that the longer he sticks around, the more sperm he can pump into the female and the greater his odds of fathering the next generation. It’s a tricky dilemma – with only two chances at mating, he should only make the choice to stay, inseminate and die if his mate is worth the trouble.

And according to Welke and Schneider, that’s exactly what happens. They found that males escaped being eaten almost half of the time (47%) if they were mating with their sisters, but just a fifth of the time (22%) if they mated with an unrelated female. This was directly related to the length of their flings – when they had sex with sisters, they left after 5.8 seconds but they kept at it for 9 seconds when it came to unrelated females.

Of course, it’s possible that this represents a choice on the part of the female – perhaps she cuts the male off early if he’s a relative. However, Welke and Schneider think that this is unlikely because females will attack any male regardless of how closely related he is. They get their say by choosing to mate with another male if they wish. The decision to end sex early appears to be the will of the male.

But why should a male mate with their sister at all, if she’s such an undesirably partner? The duo suggests that males lead precarious lives anyway, and the longer they spend searching for a mate, the greater their odds of dying before becoming fathers. So high is this risk that they’ll accept even undesirable mating opportunities; they’ll just try to move on to better things without getting eaten first.

Reference: Biology Letters http://dx.doi.org/10.1098/rsbl.2010.0214

More on cannibalism:

• March of the locusts – individuals start moving to avoid cannibals
• Attack of the pregnant cannibal fathers

Mr. Carl Zimmer points me to a new article in Nature, Neanderthals may have interbred with humans. The details within the article are more tantalizing, it seems to me, than the headline would imply.

The topline is this, researchers presented the following at the recent meeting of the American Association of Physical Anthropologists:

* An analysis of 614 highly variant loci, microsatellites, in ~2,000 people from diverse populations imply some variants which seem to be derived from human lineages outside of the mainline which led to the anatomically modern humans who left Africa 50-100,000 years before the present to settle the world. I assume there were “long branches” on the phylogenies of some loci, indicating that some of the alleles were “separated” from others for long periods of time so that recombination wasn’t able to dissolve the differences between distinctive haplotypes (if we’re all descended from a small African populations which expanded demographically less than 100,000 years ago the common ancestor of the variants should have a shallow time depth).

* The data imply two admixture events, one 60,000 years ago in the eastern Mediterranean, the other 45,000 years ago in East Asia. I think of this as a floor to the number of events. The latter one seems particularly clear in Oceanic populations from the reporting.

* African populations do not have the variants for these two admixture events (there hasn’t been that much back migration to Africa aside from north of the Sahara and the Horn of Africa. I assume that’s because Africans are well adapted to their environment, and outsiders are not).

In light of the recent discovery of a Siberian hominin which lived ~30,000 years ago, and was not a H. sapiens sapiens or H. sapiens neanderthalis, as well as the confusing but intriguing Hobbits of Flores, I think we can conclude that the the evolutionary genetic past was much more complicated than we’d assumed 10 years ago. Remember three years ago when there was a spate of research on a few genes which were suggestive of introgression into the human genome from Neandertals? There are other hints here and there which pop up in the literature over the years, some in Asia. But the methods being imperfect, and interpretation being somewhat an art, a consensus of Out-of-Africa + total replacement has been assumed to be a null. So we look at isolated results with some skepticism (I think this is justified).

So is this going to be met with skepticism due to reliance on the orthodox model? This section of the article is intriguing:

A test of the New Mexico team’s proposals may come soon. Svante Pääbo and colleagues at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, announced early last year that they had finished sequencing a first draft of the Neanderthal genome, and they are expected to publish their work in the near future. Pääbo’s earlier studies on components of Neanderthal genomes largely ruled out interbreeding, but they were not based on more comprehensive analyses of the complete genome.

Linda Vigilant, an anthropologist at the Planck Institute, found Joyce’s talk a convincing answer to “subtle deviations” noticed in genetic variation in the Pacific region.

“This information is really helpful,” says Vigilant. “And it’s cool.”

Trying to glean what results Paabo is going to come out with is like reading tea leaves, but it is notable that a colleague at Max Planck seems to be excited about the results of this study. I do not get the sense that any of these results would reject the model that the overwhelming signal of ancestry in non-African humans is African. There’s a reason that mtDNA, later analysis of classical markers, and finally modern genomics (as well as cladistic analysis of skeletal features) imply that there was an Out of Africa event, whereby anatomically modern humans entered into a period of massive demographic and range expansion from a small ancestral group. But that does not preclude the assimilation of other groups along the way, and there is circumstantial evidence of sex between the Others and modern humans (the time of separation between various hominin lineages is on the low side in relation to various other taxa which can still produce fertile hybrid young).

A final point is that if these results hold up, one might look to Africa itself for other hybridization events. It may be that ancient hominin genetic variation is preserved in modern Africans as H. sapiens sapiens entered its period of expansion within that continent. Those signals may be currently obscured because the archaics in Africa were genetically more similar than those outside of Africa, and the African genome hasn’t been as well characterized as that of other populations in relation to its great diversity (remember the finding of new SNPs in the recent paper on Bushmen).

Image credit: National Geographic

So, I’ve been working very hard over the past month to organize an event with Sheila Jasanoff of the Harvard Kennedy School about the state of science blogging. The event is cosponsored by Jasanoff’s Science, Technology, and Society Program and the MIT Knight Fellowship in Science Journalism. I’ll be putting up much more information about it very soon, but for now, just a teaser….the truly rockin’ poster: C’mon, you know you want to attend….

Some weird results on potential Neanderthal interbreeding are coming out. Nature News has a write-up. Hat tip, Vaughn Bell.

There is some interest in the upcoming British election, and the renaissance of the Liberal Democrats under Nick Clegg. See this article in The New York Times about the rise of the Liberal Democrats at the expense of the two traditional parties of power, Labour and the Tories. One interesting fact from an American perspective is that Nick Clegg is an admitted atheist, though his children are being raised Roman Catholic by his wife. Of course the lack of faith of British politicians isn’t that new, two Prime Ministers were not even nominal believers, Clement Attlee was an agnostic and James Callaghan was an atheist.

This is of course in sharp contrast with the United States where all politicians operationally have to avow a religious affiliation, and the higher that a politician ascends up the ladder of achievement the more vocal and thorough the assertions of sincere faith have to become. And yet it is Britain which has an established church, where the head of state is the head of the church, and, religiously oriented schools receive public funding.

There are many models rooted in history one could propose, but the facts as they are would probably be unlikely to be inferred from prior axioms. It’s a reminder that human social affairs are the outcome of messy dynamics, and observation is often far easier than deep analysis. In 1800 one would reasonably have expected that it was in the United States where “infidel” politicians would flourish, and yet that has not been so.

LiveScience:
The Eyjafjallajokull volcano in Iceland, which began erupting on Wednesday, April 14, has been churning out volcanic ash that’s electrified with lightning. Credit: Olivier Vandeginste.

Salvia divinorum: effects and use among YouTube users.

“Salvia divinorum (salvia) is an intense, short-acting hallucinogenic plant gaining popularity among adolescents in the United States. There has been little scientific documentation of salvia’s effects. The popular video-sharing website YouTube has received literally thousands of video-posts of people using salvia. The objective of this study was to assess the effects of salvia use through systematic observations of YouTube videos. A sample of salvia videos was obtained using the search term “salvia.” The videos were further screened and only videos that captured the entire drug “trip” without video edits were included in the analyses described here (n=34). Three trained research assistants independently watched the videos and rated their observations on 42 effects in 30-s intervals. Onset of symptoms was quick (often less than 30s) and tended to dissipate within 8min. Further, there was a relationship between salvia dose and effect duration. Since salvia’s effects on humans are largely undocumented, this study provides the look at users in a non-laboratory environment (e.g. self-taped videos) exhibiting impairments and behaviors consistent with this powerful hallucinogen. Also, this study demonstrates the feasibility and shortcomings of using YouTube videos to assess emerging drugs and drug effects.”

Image: YouTube/ShivihS

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Discoblog: NCBI ROFL: Is that bee on crack? Oh, wait…it is.
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Discoblog: NCBI ROFL: Pink Floyd hallucinations: not just for druggies.

WTF is NCBI ROFL? Read our FAQ!

And we’ve reached the final installment of the From Eternity to Here book club. Chapter Fifteen is entitled “The Past Through Tomorrow,” in an oblique allusion to Robert Heinlein, my favorite author when I was younger. We’re going to throw in the Epilogue for good measure.

Excerpt:

What we’ve done is given the universe a way that it can increase its entropy without limit. In a de Sitter universe, space grows without bound, but the part of space that is visible to any one observer remains finite, and has a finite entropy—the area of the cosmological horizon. Within that space, the fields fluctuate at a fixed temperature that never changes. It’s an equilibrium configuration, with every process occurring equally as often as its time-reverse. Once baby universes are added to the game, the system is no longer in equilibrium, for the simple reason that there is no such thing as equilibrium. In the presence of a positive vacuum energy (according to this story), the entropy of the universe never reaches a maximum value and stays there, because there is no maximum value for the entropy of the universe—it can always increase, by creating new universes.

This is the chapter where we attempt to put it all together. The idea was that we had been so careful and thorough in the previous chapters that in this one we could be fairly terse, setting up ideas and knocking them down with our meticulously-prepared bludgeon of Science. I’m not sure if it actually worked that way; one could argue that it would have been more effective to linger lovingly over the implications of some of these scenarios. But there was already a lot of repetition throughout the book (intentionally, so that ideas remained clear), and I didn’t want to add to it.

Of course my own current favorite idea involves baby universes pinching off from a multiverse, and I’m certainly happy to explain my reasons in favor of it. But there are also good reasons to be skeptical, especially when it comes to our lack of knowledge concerning whether baby universes actually are formed in de Sitter space. What I hope comes across is the more generic scenario: a multiverse where entropy is increasing locally because it can always increase, and does so both toward the far past and the far future. While there’s obviously a lot of work to be done in filling in the details, I haven’t heard any other broad-stroke idea that sounds like a sensible dynamical origin for the arrow of time. (Which isn’t to say that one won’t come along tomorrow.)

Chapter 16 is the Epilogue, where I reflect on where we’ve been and what it all means. I talk a little about why thinking about the multiverse is a very respectable part of the scientific endeavor, and how we should think about the fact that we are a very tiny part of a very big cosmos. Finally, I wanted to quote the very last paragraph of text in the book, at the end of the Acknowledgments:

I’m the kind of person who grows restless working at home or in the office for too long, so I frequently gather up my physics books and papers and bring them to a restaurant or coffee shop for a change of venue. Almost inevitably, a stranger will ask me what it is I’m reading, and—rather than being repulsed by all the forbidding math and science—follow up with more questions about cosmology, quantum mechanics, the universe. At a pub in London, a bartender scribbled down the ISBN number of Scott Dodelson’s Modern Cosmology; at the Green Mill jazz club in Chicago, I got a free drink for explaining dark energy. I would like to thank every person who is not a scientist but maintains a sincere fascination with the inner workings of nature, and is willing to ask questions and mull over the answers. Thinking about the nature of time might not help us build better TV sets or lose weight without exercising, but we all share the same universe, and the urge to understand it is part of what makes us human.

Among those people who share a fascination with the inner workings of nature, I of course include people who regularly read this blog. So — thanks!