Fire in the hole: earliest evidence of human cooking.

April 4, 2012 • 5:59 am

You may be familiar with Harvard anthropologist Richard Wrangham’s book Catching Fire: How Cooking Made us Human, in which he posits all sorts of features of modern humans, including not only morphology (teeth and brain size), but also sociality, intersexual relationships, division of labor, and other forms of behavior were impelled by the discovery that we could cook food on fires.  I haven’t read this book but I have read about it, including an interview with Wrangham at Edge.  Based on this admittedly cursory reading, I think his hypothesis is a little simplistic (i.e., maybe easily digestible protein allows us more energy to evolved a larger brain, but there still must be selection pressures for that larger brain), but there may be something to it.  However, there are many other alternative theories for bigger brains (my favorite is social interaction and language), several of them may have operated simultaneously, and it’s hard to discriminate among them.

One piece of evidence against Wrangham’s hypothesis was, until now, the finding that enlargement of human brains appeared to have begun well before hominins started cooking.  Brain size enlargement in humans is traditionally throught to have begun its rapid phase with Homo erectus, about 1.5 million years ago, although there may have been an evolutionary speedup about 300,000 years ago. (Wrangham has also noted that human molar teeth underwent a relative reduction in size at that time, which one might expect if we were processing cooked rather than raw foods.)  But the first evidence for controlled use of fire was about 400,000 years ago.  There had been earlier reports of burned bones and vegetation associated with human presence from 1.5 million years ago, but those might have been due to wildfires rather than fires controlled by humans.  (Controlling is important if cooking is to be frequent enough to affect our evolution.)

Now, however,  a new paper in PNAS by Berna et al. (free download!) gives a pretty unequivocal report of controlled fire use about 1 million years ago, in “Wonderwerk Cave,” in northern South Africa:

The evidence for controlled fire use includes the fact that there are multiple findings well inside the cave of charred bone and burnt plant material.  The source of the bones wasn’t identified, but presumably they’re animals rather than human (no cannibalism!), and reflectance spectra of the bones that match the spectra of newly heated bones and differ from those of unheated bones.

The burnt plant material was not wood but grasses, leaves, or brushes, indicating that humans hadn’t yet perfected the use of cooking over logs (this of course meant that they had to feed the fire constantly).  The reflectance spectra suggests that bones were heated to a temperature between 400 and 500 degrees C, which is hot enough to cook stuff but not hot enough to cook a steak well done (but why would they want to?).  The highest temperature suggested by bone and plant scans is about 700 degrees C—not hot enough to be produced by wood.

Here are a couple of pieces of charred bone for your inspection (these are from the paper):

And here’s a bit of “ashed plant material” along with the bone fragments (don’t ask me which is which):

The authors conclude this:

Thus, our data, although they do not show evidence of constructed combustion features, as listed by Roebroek and Villa as a criterion of controlled burning (3), demonstrate a very close association between hominin occupation and the presence of fire deep inside Wonderwerk Cave during the Early Acheulean. This association strongly suggests that hominins at this site had knowledge of fire 1.0 Ma. This is the most compelling evidence to date offering some support for the cooking hypothesis of Wrangham(1).

Note how carefully the authors hedge their conclusion; this is good science, showing that conclusions are tentative.

_____________

Berna, F., et al. 2012. Microstrategraphic evidence of in situ fire in the Archeulean strata of Wonderwerk Cave, Northern Cape province, South Africa. Proc. Nat. Acad. Sci. USA: published ahead of print April 2, 2012, doi:10.1073/pnas.1117620109

For the earlier suggestion that human morphology of a million years ago had already been evolutionarily molded by the use of fire, see:
Organ C, Nunn CL, Machanda Z, Wrangham RW. 2011. Phylogenetic rate shifts in feeding time during the evolution of Homo. Proc Natl Acad Sci U S A. 2011 Aug 30;108(35):14555-9. Epub 2011 Aug 22.

A reader describes what will make him accept evolution

April 3, 2012 • 11:01 am

A new reader, “Blas”, submitted this comment (to follow my “modest proposal” post) on what would make him accept evolution (I’m assuming he’s a “he” because “Blas” sounds male):

I will believe in evolution when I listen darwinist tell his fiance or his wife:

“The chemistry of my body make me feel good when I see you. I´m telling this to you because may chemistry is making me tell that, not because I´m free to say this or other thing”

instead of “I love you”

I will believe in evolution when I listen darwinist tell his childrens:

“The chemistry of my body make me feel good when I see you, because the vision results in the possibility that my shelfish genes will survive.I´m telling this to you because may chemistry is making me tell that, not because I´m free to say this or other thing”

instead of “I love you”

Well, perhaps this guy is not a human but a mollusc (“shelfish genes”), but regardless, this is not necessarily evidence for evolution. It is evidence for emotions and feelings coming from physiology, something that many antievolutionists can accept, I suppose. After all, God could work through hormones, too, just as theists tell us he works through natural selection.

And I’m puzzled by how Blas mixes up physiology with free will.  Presumably many of the compatibilists who post here would readily admit that our feelings are conditioned by hormones.  Indeed, we can change a person’s feelings by adjusting his/her hormone titer.

At any rate, let’s turn this guy around.  I can tell him that I have had a female tell me that her feelings for me were due to a surge of oxytocin.  I don’t have a family, but perhaps one mother or father can verify that they’ll tell their children that their feelings of love derive from natural selection, promoted by inclusive fitness, that acted on genes that produce hormones and emotions.

All it takes is one of us to say these things and—presto—Blas will become a Darwinian!

Too windy for you?

April 3, 2012 • 8:16 am

Last week Matthew Cobb put up a nice animated map of the world’s ocean currents. Today, courtesy of alert reader Ken, we have a cool real-time map of where and how strongly the winds are blowing in the U.S. at this moment:

Animated wind map here.

You can click on any point to enlarge the map and find out the local wind-speed reading.

Right now it’s blowing gusts down the central U.S., but things are pretty calm in Chicago.

A modest proposal (not mine): how do we get Americans to accept evolution?

April 3, 2012 • 5:59 am

No doubt about it, Richard Dawkins was “stridency” in his Reason Rally talk in D.C.  You can find the transcript of his speech here, which include the following controversial call to arms:

So when I meet somebody who claims to be religious, my first impulse is: “I don’t believe you. I don’t believe you until you tell me do you really believe — for example, if they say they are Catholic — do you really believe that when a priest blesses a wafer it turns into the body of Christ? Are you seriously telling me you believe that? Are you seriously saying that wine turns into blood?” Mock them! Ridicule them! In public!  Don’t fall for the convention that we’re all too polite to talk about religion. Religion is not off the table. Religion is not off limits.

Religion makes specific claims about the universe which need to be substantiated and need to be challenged and, if necessary, need to be ridiculed with contempt.

There’s a time for stridency, and I have no objection to these remarks, which will undoubtedly be seen by faitheists and believers as a call to mock people, not their ideas. (Another example of an unclear antecedent!).  And, indeed, at a piece at 3 Quarks Daily, “Should we address the controversy?“, Quinn O’Neill interprets this as an obvious call to make fun not of peoples’ beliefs, but of people themselves:

Ridicule can take many different forms, including well-crafted satire and cartoons like South Park, but Dawkins is suggesting that we make fun of people face-to-face. “Mock them! Ridicule them! In public!” he instructs.

And she goes on to make the obvious point—a point so obvious that no evidence is ever adduced in its favor—that one must coddle the faithful to bring them to Darwin:

Being a well-known advocate for evolution, Dawkins’ advocacy of hostile anti-theism may have an undesired effect. For some people, he may be reinforcing an association between evolution and a threat to something that they value. From a marketing perspective, this would be an obvious blunder. It’s like reminding people that Coke promotes tooth decay when you actually want them to buy Coke.

That reminds me of what the geneticists J. B. S. Haldane called “Aunt Jobiska’s theorem,” which is “It’s a fact the whole world knows!” (Ergo, no need for evidence: it’s what Alvin Plantinga calls a “basic belief.”  When accommodationists come up with some evidence that telling the faithful that Jesus and Darwin are compatible will turn more of them to evolution than straight-out critique of religious belief, then I’ll sit up and take notice.

But there’s no doubt, at any rate, that “strident” critiques of faith do make converts to both atheism and evolution. I keep pointing people to Dawkins’s “Converts corner,” in which people testify to a Dawkins-induced conversion, and accommodationists keep ignoring it, saying that it’s only anecdotal evidence.  But there are 44 pages of conversion tales. In contrast, I haven’t seen a single anecdote in which an evolution-denier finally accepted evolution after an accommodationist convinced them that Jesus and Darwin were friends.  Where is Kenneth Miller’s “Converts corner”? Whence Francis Collins’s “Converts corner.”  All these people produce is arguments rather than evidence, and then dismiss 44 pages of evidence as “anecodotes.”  Pardon me if that’s not a good enough reason to abandon my critique of faith!

But I digress.  O’Neill’s point in her piece, beyond dissing Dawkins, is to propose a new way to convince people of evolution.  Her inspiration, apparently, was a class I taught at the University of Maryland, in which I lectures to students on Monday as an evolutionist (discussing, for instance, the fossil evidence for evolution), and then as a creationist on Wednesday, knocking down all the evidence I’d adduced two days before. On Friday I monitored a discussion among the students, trying to sort out the conflicting views and come to a conclusion.  As Quinn notes, the class was pretty successful in bringing creationist students around to evolution. (The turning point was their realization of how ridiculous “flood geology” was: that a simply hydrodynamic sorting of organisms caught up in the Great Flood could never have produced the fossil record we see.)

From this Quinn suggests a series of debates:

So here’s an idea, partly inspired by Coyne’s classroom success. It may be ridiculous and completely unfeasible. I’m offering it here in the hope that it might generate some ideas beyond either ridiculing or coddling religious people.

I propose an evolution vs. creationism debate with representation for each side that would be deemed worthy by proponents of each view – perhaps representatives from a national science organization like the NSF or the NCSE, and from a creationist institution, like the Discovery Institute. The debate wouldn’t be public or in person and the time frame would allow for careful formulation and revision of arguments and rebuttals. Respective parties would be free to formulate their response in groups or appoint people they deem up to the task. The number of back-and-forths permitted should allow the entire process to be completed in a reasonable time frame, maybe a few months. The end result would be a formal debate which presents each side’s views and let’s students decide what to think, just as proponents of “teaching the controversy” claim to want.

I envision this debate being part of a booklet that might also contain brief deconstructions of common evolutionary misconceptions and maybe a section on the nature of science. I would have copies in science classrooms and school libraries. Teachers could mention the resource to students and encourage them to read it but still refrain from discussing religion in the classroom. It would be a supplemental curriculum resource not intended to replace coverage of evolution in the curriculum.

In addition to schools (science classrooms and school libraries), perhaps this booklet could be distributed to public libraries and museums and available online for order and/or download. It might be nice to have copies available for handout at various events, like Darwin Day celebrations. . .

I think this could be helpful for a number of reasons. I personally found a transcript of an evolution vs creationism debate to have a sizable impact on my own thinking about the issue. The debate was between Isaac Asimov and Duane Gish. It was only a few pages in length, but it sealed the deal for me in high school.

I think she’s envisioning the kind of written back-and-forth that occurred on the internet between, say, Sam Harris and Andrew Sullivan.  Her suggestion is well motivated, but I don’t think it’s feasible for several reasons.

  • Do we really want to waste time in biology classes with a long segment on intelligent design?
  • Intelligent design is only one aspect of creationism; indeed, there are probably just as many, or more, young-earth ex nihilo creationists as ID creationists. And even ID creationists differ among themselves: Michael Behe, for example, accepts a limited form of common descent, while others like Paul Nelson (and probably Dembski) don’t.  Who will represent creationism?
  • A debate that devolves into details like malaria resistance and the flagellum will quickly exhaust the patience, interest, and mental resources of students.
  • You can’t “refrain from discussing religion in science classrooms” so long as you talk about ID, since an integral concept of that brand of disredited thought is a supernatural designer.
  • It wouldn’t work without a monitor to guide discussion.  In my own class, described by Quinn, I was able to guide discussion (but not force evolution down kids’ throats) by making them stick to reasons for their beliefs.  But that was an entire course, and not a biology course (it was a “general ed” course).  Perhaps this idea could be part of a general course on critical thinking rather than a huge segment interpolated into a biology curriculum.
  • Such a procedure would be of limited effectiveness given that most people’s rejection of evolution comes from their religious beliefs rather than their comprehension of or rejection of biological evidence.

To truly rid the world of creationism, weakening religion is, in my view, the more effective tactic—and has all the other benefits that come with the disappearance of faith.  Here are some poll results
that I cite often:

When asked what they would do if scientists were to disprove a particular religious belief, nearly two-thirds (64%) of people say they would continue to hold to what their religion teaches rather than accept the contrary scientific finding, according to the results of an October 2006 Time magazine poll. Indeed, in a May 2007 Gallup poll, only 14% of those who say they do not believe in evolution cite lack of evidence as the main reason underpinning their views; more people cite their belief in Jesus (19%), God (16%) or religion generally (16%) as their reason for rejecting Darwin’s theory.

Quinn doesn’t realize that the goal of people like Dawkins, P. Z. Myers, and myself is not simply to get students to accept evolution.  It’s to weaken those forms of uncritical thought, born of superstitition, dogma, and revelation, that create many worse harms than teaching creationism in the public schools. So, while Quinn’s conclusion sounds good—

Additionally, I think it’s generally more important for people to think for themselves than to think like I do. For this reason I think focusing efforts on promoting debate, providing facts and arguments, and appealing to reason is a superior course of action than face-to-face mockery. While the former approach enhances the critical thinking process, the latter punishes the conclusion. It’s possible that mockery may induce some people to examine their views more critically, but we don’t have any idea what percentage of the time this happens.

There’s much better evidence for the effectiveness of debate and appeals to reason than there is for the effectiveness of face-to-face ridicule. There also seems to be greater potential for harm with ridicule. Ridicule is like the homeopathy of available approaches and fundamentalism like a cancer.

—remember that she adduces no evidence for what she says.  We do have some idea that mockery does work (and what Richard does is far more than mockery: it’s a critique of irrational and unevidenced ideas).  We have no idea “what percentage of the time” accommodationism unites Jesus with Darwin in peoples’ minds.  If Quinn wouldn’t mind, I’d love her to give evidence for her statement that criticizing religious views is much less effective than coddling the faithful in bringing acceptance of evolution.  All we have are a few studies showing that people are more mentally receptive to views that are consonant with theirs than opposing critical views.  But do remember that we’re aiming not at the faithful themselves, but mostly at those people on the fence, especially young people.

I would like accommodationists like Quinn to give some evidence that, in the long run, it’s easier to bring people to Darwin by fostering public debate than by criticizing religion.  And remember, I said “in the long run.”  In the long run, we’ll always have the brushfires of creationism since they’re ignited by the match of faith.

Kitteh contest: Peanut and Spot

April 3, 2012 • 4:19 am

Reader Cameron sends photos of his two cats.  First up is Peanut—rather, a moiety of Peanut:

Yes, that’s our Peanut. He’s crazy.
That marker was just sitting on the bar and he was looking at it sideways, looking above and below the bar and reaching up to grab the marker.

And Spot (note: the “DQ” on the cup stands for “Dairy Queen,” an American chain that purveys ice-cream products):

Here’s one of our Spot. He’s a little overweight. He’s always hungry. He’ll drink out of your glass of water if you’re not careful or, in this case, have some of your shake.

Political correctness gone wild: NYC wants to ban mention of dinosaurs, evolution, and pepperoni on standardized tests

April 2, 2012 • 10:31 am

Get this: New York City wants to ban the words “dinosaurs” and “evolution” from standardized school tests because the words are considered “controversial.”  According to CNN, these are merely a few of fifty words that are to be deep-sixed from the tests because they’re considered “loaded” or because they may offend child and adult sensibilities:

The banned word list was made public – and attracted considerable criticism – when the city’s education department recently released this year’s “request for proposal” The request for proposal is sent to test publishers around the country trying to get the job of revamping math and English tests for the City of New York.

The Department of Education’s says that avoiding sensitive words on tests is nothing new, and that New York City is not the only locale to do so. California avoids the use of the word “weed” on tests and Florida avoids the phrases that use “Hurricane” or “Wildfires,” according to a statement by the New York City Department of Education.

In its request for proposal, the NYC Department of Education explained it wanted to avoid certain words if the “the topic is controversial among the adult population and might not be acceptable in a state-mandated testing situation; the topic has been overused in standardized tests or textbooks and is thus overly familiar and/or boring to students; the topic appears biased against (or toward) some group of people.”

Here, from SIlive.com (a site from Staten Island) is a complete list of the 50 banned words.  “Dinosaurs” doesn’t appear here, but does on other lists, and note the E-WORD (my emphasis):

  • Abuse (physical, sexual, emotional, or psychological)
  • Alcohol (beer and liquor), tobacco, or drugs
  • Birthday celebrations (and birthdays)
  • Bodily functions
  • Cancer (and other diseases)
  • Catastrophes/disasters (tsunamis and hurricanes)
  • Celebrities
  • Children dealing with serious issues
  • Cigarettes (and other smoking paraphernalia)
  • Computers in the home (acceptable in a school or library setting)
  • Crime
  • Death and disease
  • Divorce
  • Evolution
  • Expensive gifts, vacations, and prizes
  • Gambling involving money
  • Halloween
  • Homelessness
  • Homes with swimming pools
  • Hunting
  • Junk food
  • In-depth discussions of sports that require prior knowledge
  • Loss of employment
  • Nuclear weapons
  • Occult topics (i.e. fortune-telling)
  • Parapsychology
  • Politics
  • Pornography
  • Poverty
  • Rap Music
  • Religion
  • Religious holidays and festivals (including but not limited to Christmas, Yom Kippur, and Ramadan)
  • Rock-and-Roll music
  • Running away
  • Sex
  • Slavery
  • Terrorism
  • Television and video games (excessive use)
  • Traumatic material (including material that may be particularly upsetting such as animal shelters)
  • Vermin (rats and roaches)
  • Violence
  • War and bloodshed
  • Weapons (guns, knives, etc.)
  • Witchcraft, sorcery, etc.

CNN continues:

Matthew Mittenthal, a spokesman for the NYC Department of Education, said this is the fifth year they have created such a list.  He said such topics “could evoke unpleasant emotions in the students.”

“Dinosaurs” evoking unpleasant emotions? The New York Post speculated that the “dinosaurs” could “call to mind evolution, which might upset fundamentalists.”

But what the tabloid failed to realize is that those “fundamentalists” who oppose evolution on religious grounds, believe wholeheartedly in dinosaurs.

Anyway, a lot of the list appears to pander to religious concerns.  That’s okay insofar as favoring one faith over another, or faith over atheism, violates the Constitution. But this degree of extremism is simply stupid:

Apparently many of the words on New York’s list were  avoided because of faith-based concerns.

For instance, the use of the word “birthday” or the phrase “birthday celebrations” may offend Jehovah’s Witnesses, who do not celebrate birthdays. A spokesperson for the Jehovah’s Witnesses declined to comment on the use of the word “birthday.”

The Department of Education would not go on the record to explain the specific reasons for each word, which has left many to speculate and draw their own conclusions.

Halloween may suggest paganism; divorce may conjure up uneasy feelings for children in the midst of a divorce within their family. One phrase that may surprise many, the term “Rock ‘n’ Roll” was on the “avoid” list.

And not good news for Italians: the Department of Education also advised avoiding  references to types of food, such as pepperoni, products they said “persons of some religions or cultures may not indulge in.”

Good Lord, the degree to which children are protected these days! Kids can’t even ride their bikes around the neighborhood any more. (Do I sound like a curmudgeon? Very well, then, I sound like a curmudgeon. I am large; I contain many ages.) I agree with Stanford education professor Sam Weinburg, who, when told about the list, had this response:

When reached by phone said Wineburg, after a brief pause on the line, “the purpose of education is to create unpleasant experiences in us. … The Latin meaning if education is ‘to go out.’  Education is not about making us feel warm and fuzzy inside.”

Wineburg questioned the idea that the New York City Department of Education would want to “shield kids from these types of encounters.”  He said the goal of education is to “prepare them,” adding “this is how we dumb down public schools.”