This news just appeared.  The conventional wisdom for the last decade has been that Neanderthals died out without leaving any descendants.  That is, their genes died with them.  Although Neanderthals were contemporaries of H. sapiens, and might have mated with them, they either didn’t hybridize or their “hybrids” were sterile.

Now, a new study by Svante Pääbo and his colleagues confirms that this genetic “introgression” did indeed take place, and that between 1% and 4% of the DNA of Europeans, Asians, and Papua New Guineans is attributable to hybridization between “modern” humans and Neanderthals.  The paper will appear in Science tomorrow, and is not yet online, so I haven’t seen it. There are reports at the Guardian and the BBC, and the figure from the BBC website is below.

Oh, and Carl Zimmer, who’s undoubtedly seen the paper, has more.

Fig. 1. Introgression!  Neanderthals copulate with Homo sapiens!

As one of my colleagues, who will remain unnamed, wrote me: “Now here’s a piece of speculation – what will happen when they get round to the floresiensis genome? I presume someone is beavering away at it. If we f****d Mr. or Ms. Chunky, surely we had a shag with the leprechauns!”

Update:  The paper is now online here.  Look at all the authors!  And although I mentioned Pääbo above, the first author is Richard Green.

More on this later.

h/t: Greg Mayer and Matthew Cobb for the alert.

When people study primate behavior with the idea of relating it to human behavior, standards of evidence often seem quite low.  There’s a lot of publicity and attention to be gotten by detecting the roots of our behavior in the other apes that are our relatives.  Who among us hasn’t been fascinated by going to the zoo, watching a chimp, and saying, “Wow–they’re so much like us!”

This is not to deny that some of our behaviors descend from those of apey ancestors. They do, of course, and Darwin was the first to write about it. But we also have culture that can rapidly transmit un-apelike behaviors across diverse groups (e.g., dancing and making music).

The attention-getting power of rather thin evidence from apes is seen in a new paper in Primates by Christel Schenider et al., “Do bonobos say NO by shaking their head?” You can already tell what the answer to their question is, for had it been “no” (i.e., chimps don’t say “no” by shaking their head), the paper wouldn’t have been published.

The authors studied infant bonobos (pygmy chimps, Pan paniscus) in three German zoos,  In 190 hours of taping bonobo infants, they observed 13 instances in which an adult chimp appeared to shake his/her head in a  human “no”-like way in association with trying to prevent an infant from doing something.  An example:

The mother and her female offspring were sitting next to each other on the ground. The offspring started crawling away toward a nearby tree trunk and proceeded to climb. The mother retrieved the infant and positioned her back to her side. The infant made continual efforts to climb the trunk, and each time the mother retrieved her. This culminated in the mother seizing the infant by the leg and shaking her head while looking toward her. The infant climbed once again, this time moving around the tree (now out of sight of the mother). After awhile, the mother got up, moved around the tree, grabbed the infant’s arm, and pulled her to the place where they originally sat. When releasing the infant the mother looked at her and shook her head once more. The mother started grooming another group member, and the infant moved toward the tree again.

You can see one of the videos at the BBC website; that and another are also at the Primates website if you have access.  Sure looks like a “no” to me!

But wait. If you read the paper, you’ll see that there were actually 49 behaviors identified as “head shakes,” and, as the authors note, “The remaining 36 (nonpreventive) head shakes were used to initiate to to maintain behavior in various contexts. These were predominantly play (n = 25), e.g., to initiate play with a group member, and affiliation (n = 6), e.g., to approach and greet a group member.”

In other words, nearly three-quarters of the head shakes were associated with affirmative rather than preventive stuff.  Further, ten of those 13 head shakes were made by a single mother, so there were only four adults involved in the behavior.  It’s hardly a pan-Pan trait!

So what do the authors conclude?  They don’t wildly extrapolate to humans, but do draw the connection:

If the use of preventive head shaking is confirmed in genus Pan, this would raise a further, more speculative, evolutionary question: Do these gestures reflect a primitive precursor of the human head shake that denotes negation? This is an intriguing possibility, but additional data along the lines indicated above will be needed to provide an informed answer.

Well, maybe, but 13 preventive head shakes and 36 “affirmative” ones doesn’t seem to me like a lot of evidence.  I’m not very impressed.

But the BBC takes it further, calling their report on this finding “Bonobo chimps filmed shaking their head to ‘say no’.” (For language freaks, shouldn’t “head” be plural?) And they say this:

The researchers are cautious to say that they cannot be sure the bonobos definitively mean ‘no’ when they shake their heads this way.

But it remains the best explanation so far.

Best explanation for what?  In how many “preventive situations” did the chimps not shake their heads in a “no-like” fashion.  And what about those other times when head-shaking was associated with positive stuff?  Does head-shaking explain that, too?

There’s one other matter.  Do all humans really say “no” by shaking their heads?  Many societies do this, but I’m not so sure the behavior is a cultural universal.

During the months I spent in India, I learned that Indian head-gestures for “yes” and “no” are very different from ours. When the head is drawn back upwards, looking like part of a “yes” nod, it really means “no.” A side-to-side waggling, however—(the “Indian head bob“)—which looks much like our “no”, means “yes.” It took me a while to learn that when I thought I was being refused, I wasn’t.

And, in fact, the chimp’s head shake in the BBC video looks very much like the “nodding” and affirmative Indian bobble:

Apparently the same gestures hold in Bulgaria:

Schneider admits this cultural variation in her interview with the BBC, but the authors sure don’t discuss it in the Primates paper, saying only that “[head shaking] is generally associated with an explicit or implicit negative connotation in many parts of the world.”  And we simply have no idea how early hominins used their heads to gesture “no,” or whether what generality there is among cultures in the “no-shake” might be based on cultural inheritance instead of being—as the BBC suggests—”hardwired” in humans.

Of course very few people who read the BBC report will read the original paper.  Pity.

h/t: Matthew Cobb, Otter

_______

Schneider, C., J. Call and K. Liebal.  2010.  Do bonobos say NO by shaking their head?  Primates online, doi: 10.1007/s10329-010-0198-2

Okay, I’m going to play Andy Rooney.

You know what really bothers me?  Psychics. My peregrinations on the Web led me to a UK site where pet psychics claim to help you tune into the “morphogenic field” of your dog or cat:

And while they say they “don’t promise miracles,” in fact they do, for they will put you in touch with the late Fluffy:

If you are looking for proof of life after death you may want to first ask our operator for advice about which psychic medium to choose. A medium usually connects with the spirit of a family member and they in turn may give you some proofs that the animal you’ve lost has survived death.

This ticked me off, because I’m an animal lover and can well imagine that some non-atheist, grieving over their dead pet, may decide that Mittens is still alive over the Rainbow Bridge.  And people like the psychics at this site make money from fleecing those gullible individuals.

This stuff isn’t limited to the UK. With a bit of Googling, you can find many similar scams in the U.S.  Here’s American “pet psychic” Laura Stinchfield, who claims to put owners in touch with their dead animals:

Can you talk to deceased animals?

Yes. I find this to be of great value to people who are suffering over the death of their animal. Talking to your animal is a wonderful way to aid in closure. Once our animals have passed they meet their old friends in heaven, their suffering is gone and replaced with bliss, they are given a job, and they are able to watch over us and protect us. They can give us amazing insight. It is only us that suffer when they leave us in body.

Occasionally, an animal may be stuck and need help in transitioning into heaven. If that is so, I can help with that transition. When I say “stuck” I meaning the animals may not have crossed over. This can happen if an animal dies suddenly (hit by a car or killed by a coyote) and they don’t know that their [sic] are not in their body anymore. It can also happen if their people are grieving and holding on to them so tightly that the animal feels frightened to cross over and wants to stay. They do not understand that they need to cross over and then come back to watch over their people.

I like to give the animals three days after death to transition before I do a session with them.

Holy crap! More fleecing.  More sad people, lighter in the wallet.

But there are many more psychics who deal with problems about love, money, and dead human friends and lovers.  You can find many of these at the American Psychic Directory. Now some of these folks may just claim to offer “spiritual guidance,” which is, I guess, ok, and some of these who do “readings” are really giving advice based on their take of the client’s psychology.  But some of these psychics also claim that they can put you in touch with dead relatives.  Here’s Erin Pavlina:

If a deceased friend or relative is going to come through during a reading they are almost always hovering around me 5-10 minutes before a reading, and I just know we are going to have contact with a deceased relative or friend.  In those cases, I am usually instructed to start with their message because it is usually important and/or urgent.

If you want to connect with someone specific on the other side, I will attempt to make contact.  I have found that sometimes they will come through and sometimes they won’t.  If they don’t come through, don’t panic.  It doesn’t mean they are not there, it just means I cannot connect with them.  It’s like ringing someone’s phone and they don’t answer.  They are there, just screening their calls.

Now I know what you’re saying: let these stupid people get fleeced—it’s just natural selection!  A fool and his money are soon parted.  But what about all those people who are promised spiritual cures or bogus medical cures for real diseases, pay a lot of money, and die? (You may have seen the 60 Minutes piece two weeks ago on bogus stem-cell therapy for cancer.)  What this has in common with psychics who promise contact with the dead, glimpses into the future, and the like, is that all of these practices are based on lies—lies totally unsupported by evidence.  The promises of bogus “cures,” however, are illegal: the stem-cell quacks will be arrested.

And all of these, including psychics, violate the advertising rules of the Federal Trade Commission, to wit:

Under the Federal Trade Commission Act:

• Advertising must be truthful and non-deceptive;
• Advertisers must have evidence to back up their claims; and
• Advertisements cannot be unfair.

Additional laws apply to ads for specialized products like consumer leases, credit, 900 telephone numbers, and products sold through mail order or telephone sales. And every state has consumer protection laws that govern ads running in that state.

What makes an advertisement deceptive?

According to the FTC’s Deception Policy Statement, an ad is deceptive if it contains a statement – or omits information – that:

• Is likely to mislead consumers acting reasonably under the circumstances; and
• Is “material” – that is, important to a consumer’s decision to buy or use the product.

Promises of psychics contravene these rules.  They are deceptive, there is no evidence for them, and they mislead consumers.  Why are they still in business?

And for that matter, why does the government still let homeopaths practice when it regularly cracks down on other bogus medical therapies?  The claims of homeopaths are also deceptive, unsupported by evidence, and misleading to consumers.  They would appear to violate the FTC’s regulations.

If advertisers make claims, they should be able to back them up.  If not, they should be driven out of business—especially those who profit from human suffering.

(I won’t say anything about churches, but only because, with the exception of tithing, they don’t demand payment.)

Fig. 1.  The late and beloved Theodore B. Coyne. I shall see him no more.

He’s 94, so what can you expect? With a title curiously close to Francis Collins’ The Language of God, author Herman Wouk produces the autobiography of an accommodationist.  Here he bedescribes him about the book:

. . . But what of A Child’s Garden of God, the title I cherished for so long? Well, when my almost infallible wife read the second part, she said, “Fine, but I don’t like your title. The book is about science and religion, and the title should say so.” I bethought me of my first meeting with Feynman, when he asked me if I knew calculus, and I admitted I didn’t. “You’d better learn it,” he said. “It’s the language God talks.” This casual remark by a towering scientist, an aggressively secular Jew, strikes the modern note with a resounding agnostic clang. The Language God Talks acknowledges my lack and offers something of what I have learned of His other language, which I know pretty well: the Bible.

If anybody has the kishkas to read this thing, report back.

By now we’re familiar with accommodationists attacking scientists as being largely responsible for not only the rejection of science by the faithful (because we’re so clueless about how to frame our work) but also for scientific illiteracy itself.  A few days ago PeeZee posted about a misguided attack by Carlin Romano on Massimo Pigliucci’s new book on pseudoscientific garbage, Nonsense on Stilts.  Romano objected to the certainty with which scientists dismiss pseudoscientific claims—a certainty that, he argues, translates into the public appearance of arrogance.

A new article on the accommodationist website BioLogos makes a similar point.  In “The dangers of advocacy in science”, molecular biologist Steven Benner claims that one reason “why non-scientists often have a difficult time understanding what scientists do” is because when we appear in public to advocate causes, we fail to convey the uncertainty inherent in the scientific enterprise.

When scientists appear in the news, they are generally sought for their advice on a matter of public policy. They are asked for certainty, not to express the uncertainty that is at the core of science correctly done. . .

The temptation to participate in the public dialogue as an advocate is considerable. I myself have been interviewed by reporters who become impatient if I actually practice science before their eyes. It is generally simpler give an answer rather than to present the context, including all of its uncertainty.

For this reason, it is important, here and elsewhere, for scientists to emphasize that uncertainty is central to science, and advocacy is disruptive of it. When a scientist becomes an advocate, he loses for himself the power to use scientific discipline to discern reality.

Indeed!  From now on whenever I defend evolutionary biology in public, I’ll make sure to emphasize that, after all, even though it’s been supported by 150 years of solid evidence and millions of facts, and there is not a single fact to suggest that the idea of evolution is wrong, some day we just might find a fossil rabbit in the Precambrian.  Maybe that public professional of uncertainty will finally make people sit up and accept evolution.

Benner fails to appreciate two things. First of all, scientist-advocates wear two hats: when we’re advocating public policy or some other social change, we are not practicing science. We are acting as humans who have concerns and science-based arguments.  Or are we not supposed to advocate anything because we’re scientists?

Of course we can be fallible (look at the scientists who deny that AIDS is caused by a virus), and we shouldn’t pretend certainty when it doesn’t exist, but do most scientists who go on radio and t.v. really pretend that they know more than they do?  That’s not my impression, and it’s telling that Benner doesn’t give a single example of the failure of scientists to show proper deference to The Great Unknown.  (He mentions doctors putting on white coats when appearing with Obama to endorse health care reform, but that’s hardly the same thing.)  And when the news does show us looking dogmatic, more often than not it’s the fault of sound-bite loving journalists who edit out all the uncertainties.  I’m quite familiar with that!

Second, some scientific advances, including the “theories” of evolution and virus causation of AIDS, are so well established that it’s simply moronic to pretend there are credible doubts about them. Usually—though not always—scientists advocate based on what they feel is reasonably well established knowledge in the field.  Do we really want doctors advocating measures against AIDS to appear on t.v. saying, “Well, you know, there are a very, very few people with Ph.D.s who feel that AIDS is simply the result of a decadent lifestyle”? It’s no smarter to hedge well established science than to hedge any other well established fact used to support a cause.

But wait—there’s a bigger problem.  What about all that advocacy based on religion?  Can we expect BioLogos to also advise the faithful to stop advocating based on their religious views?  Or at least to hedge their statements like this:

“We should prevent all abortions because even one-day-old embryos have souls.  Oh, wait. . . I forgot to add that there’s not the slightest bit of evidence that humans do have a soul.”

“You shouldn’t use condoms to prevent AIDS because God says that birth control is wrong.  Of course, we have absolutely no evidence for God’s existence.”

There’s a curious asymmetry in the views of accommodationists.  They tell us that we’re supposed to be meek, humble, respectful, and always ready to emphasize our uncertainties.  But who has more uncertainty or arrogance than the faithful, who take public stands on abortion, bioethics, conservation and the like based on beliefs for which there’s no evidence?  As always, religion gets a pass in the marketplace of ideas.

Let’s rewrite that BioLogos statement so that it addresses the other side of the faith/science debate:

For this reason, it is important, here and elsewhere, for the faithful  to emphasize that uncertainty is central to religion, and advocacy is disruptive of it. When a religious person becomes an advocate, he loses for himself the power to use faith to discern reality.

UPDATE:  Benner has written two long responses to the critiques of his post that P.Z. and I have written, accusing us of not having read his essay and of ignoring his impressive credentials as a scientist. Rather than have a long back and forth in the comments section here, I refer you to his response at Pharyngula, which you can find here (comments 39 and 40).

My own response is this: I stand by what I wrote. I do apologize for my initial misspelling of Benner’s name (which I immediately corrected when one of the commenters pointed it out). Benner beefs that P.Z. and I did not read his entire multi-part essay. That’s right:  I was not criticizing the whole thing, which I still have not read, but only his one final post on why scientists should not be advocates. It was a sloppy and misguided piece, and my comments on it stand.  And Benner’s text, which is what I criticized, was at odds with what the accompanying cartoon showed.

Perhaps the most persistent criticism of evolutionary biology is that natural selection isn’t sufficient to explain life’s complexity.  This of course is the mantra of intelligent design, which claims that in principle natural selection can’t explain “irreducibly complex” traits (for a refutation of this see the discussion at TalkOrigins).

But there’s also criticism that there is not much evidence for natural selection.  I’ve discussed this in WEIT and in my recent review of two books (and of natural selection) in The Nation.  The refutations of this claim are easy: we have lots of evidence for selection occurring in nature, including the many studies cited by John Endler in his book Natural Selection in the Wild, and more recent studies including the famous work by Peter Grant and his colleagues on selection for break size in a Darwin’s finch (for a summary of recent studies go here).

Evidence for natural selection also comes from the many observations of animals and plants responding to human-induced changes in the environment.  These include the famous studies of wing color in the peppered moth, heavy-metal tolerance in plants, insecticide resistance in insects, size changes in animals due to overharvesting, and of course antibiotic resistance in bacteria.

Some creationists object to using these cases as evidence for selection, since the selection pressures come from humans, making these (so they say) analogous to artificial selection.  This objection is misguided.  Yes, the selection pressures result from human activity, but far from trying to produce a given response, humans do not want a response.  Who wants bacteria to become resistant to penicillin?

Further, unlike animal and plant breeding, these responses to anthropogenic changes in the environment are not directed to a particular end by human desire.  When a plant evolves resistance to lead or copper on mine tailings, it’s drawing on a naturally-occurring pool of genetic variation—exactly as if the plant were responding to high concentrations of metals that occur naturally on serpentine soils.  I see all genetic responses to human meddling with the environment as evidence for natural selection, and we’re going to see more as the climate gets hotter.  Evolution is going on around us all the time, but it’s often invisible.

In the past week there have been two new reports of natural selection causing evolutionary change as a response to human activity.  The first is in today’s New York Times: a discussion of how weeds in the U.S. are becoming resistant to the herbicide Roundup.  The Roundup story is complex, but the basics are that the herbicide’s active ingredient is glyphosate, an amino acid analog that kills plants by interfering with the synthesis of some amino acids in the growing points.  It’s really effective at wiping out weeds, but can also kill growing crop plants if it’s sprayed onto fields after planting.  In the 90s Monsanto also developed “Roundup Ready” varieties of transgenic crops (which now include corn, soybeans, cotton, and alfalfa), in which they introduced into plants a gene from bacteria that allowed amino-acid synthesis to proceed normally in the presence of Roundup.  The combination of Roundup and Roundup Ready crops made millions for Monsanto, and farmers liked the convenience of not having to till the soil before planting to get rid of weeds.  But there were lots of objections to the use of transgenic crops and to the dependence of farmers on corporations who made both herbicides and herbicide-resistant crops.

But now, as reported in the Times, weeds are evolving resistance to Roundup throughout the world. As one soybean farmer observed, “We’re back to where we were 20 years ago.”  So far only about 5% of crops are infested with resistant weeds, but I can confidently predict that natural selection will make things worse.

I haven’t followed the Roundup controversy closely, but the Times reports that Monsanto “once argued that resistance would not become a major problem”.  That’s insane. Any evolutionist will tell you that you can’t predict stuff like that.  More often than not, natural selection finds a way around these things, just as bacteria have devised insidious ways to combat antibiotics, and the antibiotics that replaced those antibiotics, and so on to the point where in some cases (like TB), we have bacteria that resist all known antibiotics.

The problem will get worse, and companies will have to develop new herbicides, putting farmers into the same spiral that doctors have been in with antibiotics for decades.

Crop plants are afflicted with insects as well as weeds, and those too can adapt to human-induced selection. A new report in The Proceedings of the Royal Society of London by Vincent Calcagno et al. shows that one crop pest, the European corn borer (Ostrinia nubilalis), seems to have responded to corn harvesting by changing its behavior, making the larvae less likely to be killed during the harvest.

The corn borer appears to have evolved from the sister species Ostrinia scapulalis about 500 years ago when corn was introduced to Europe.  O. scapulalis lives on the non-crop plant mugwort (Artemisia vulgaris). Both species undergo a winter “diapause”—a period of arrested development—in the stems of their plants. (We are talking about the caterpillars here, though both develop into moths.)

Calcagno found that, unlike the mugwort-infesting species, larvae of the corn borer move down from the tops of the plant before they diapause.  This was shown both in the wild, by putting both species on either corn or mugwort, and in the lab by making artificial “stems” out of food-filled plastic tubes.  The down-movement (“negative geotaxis”) of the corn pest did not depend on living in corn, but was also seen when the corn borer was forced to live in mugwort.  In contrast, O. scapulalis did not move down at all before diapause, but tended to overwinter right where it was in the plant.

Calcago et al. speculate that this difference was due to selection associated with the harvesting of corn.  That harvesting now involves lopping off the top 15-40 cm (about 6″-16″) of the plant to get the ears.  The truncated stalks are then left standing in the field over winter.  This would impose strong selection on corn borers to diapause further down in the stalk so they wouldn’t get lopped and killed.  Calcagno estimate that this selection is pretty strong, eliminating roughly half of the corn borers.  One would certainly expect a response to that selection, and it seems to have appeared in the last few centuries. This of course makes things worse for corn farmers, because many of the pests who would be killed during the harvest now survive.

Now their case isn’t airtight, for they haven’t actually nailed down the evolutionary cause of the species difference in movement. All we see is a difference between species and a pretty plausible story that is supported by experiments.  One way to test their idea would be to see what happens in populations of corn borers that aren’t harvested—presumably they would revert to the ancestral behavior.  (Farmers wouldn’t want to do this test, of course, but it could be done in an agricultural station.)  Calcagno et al. also mention another species of corn borer, O. furnacalis, that might have evolved independently in Asia. If that species showed the same down-moving behavior it would strengthen Calcagno et al.’s case for the evolution of a corn-harvesting-associated behavior.

What all this shows is that our control over nature isn’t as strong as we think.  As the volcano in Iceland abruptly reminded us, we can’t fool Mother Nature.  And we can’t fool natural selection, either.

Fig. 1.  The European corn borer doing its job.  It’s a pest because these infestations can stunt the plant or make the ears drop prematurely. (Photo from Iowa State University.)

UPDATE: Carl Zimmer goes into more detail about Roundup at The Loom.

h/t: Greg Mayer

_________

Calcagno, V., V. Bonhomme, Y. Thomas, M. C. Singer and D. Bourguet. 2010. Divergence in behavior between the European corn borer, Ostrinia nubilalis, and its sibling species Ostrinia scapulalis: adaptation to human harvesting?  Proc. Roy. Soc. Lond. B:doi: 10.1098/rspb.2010.0433 (online).

In honor of today’s book winner, Last Chance to See, I’m putting up a 75-minute talk by Douglas Adams on the book (which he describes as his favorite) and endangered species.  This was presented in 2001 at The University of California at Santa Barbara, only a few days before Adams’s tragic death at age 49 from a heart attack.  He’s a superb speaker.

Note his mention of speciation starting at 1:08:25!  There’s a question-and-answer session at the end.