Saturday, November 28, 2009

Thursday, November 19, 2009

Human cooperation from violence?

If you think that we live in a more violent world than our predecessors, you would be agreeing with almost 300 people recently surveyed by the psychologist and writer, Steven Pinker. You would also be wrong. At a talk in the Harvard Law School, Pinker presented convincing evidence for a secular decline in violence across millennia, centuries, decades, and even years. He then attempted to answer two questions: why don't most people perceive that violence has declined, and why has it declined?

An earlier version of Pinker's ideas on violence can be found in one of his articles. Most of the talk is in it: He is now planning a book on the subject, with the potential title "The Better Angels of Our Nature".

Pinker presented three broad explanations for the secular decline in violence. Firstly, that Hobbes was quite right about life being "nasty, brutish and short", and that modern centralised states with a monopoly on violence function as Leviathan. Secondly, that technological advances have increased the number of positive-sum games, also known as win-win situations. Trade, for instance. Thirdly, that increasing ways to spread empathy, via fiction or journalism, for example, have helped to create the philosopher Peter Singer's "expanding circle". Humans are less violent now because more and more people (and sometimes animals) are included in an "in group" they can identify with.

The next day, Sarah Blafer Hrdy, renowned feminist sociobiologist, gave an equally synthetic talk on her latest book, Mothers and Others, that elaborates on the latter two of Pinker's explanations for declining human violence. Unlike Pinker, who is focusing largely on modern humans, and asking why we are so much more peaceful than ever before, Hrdy is interested in the evolutionary origins of human cooperative tendencies that far exceed those in other living apes.

I won't go into all the evidence that Hrdy presented in her talk, and in her book, but will outline her main ideas. At the moment, and ever since Darwin's Descent of Man in 1971, the predominant explanation for human cooperation is between-group conflict. The notion that our ancestors evolved to work together so they could defeat neighbouring tribes or families is apparently almost dogma amongst anthropologists.

In contrast, Hrdy contends that inter-group competition is not a sufficient, and probably not even the predominant force selecting for cooperative tendencies. Instead, she proposes that humans, unlike other apes, became extra good at sharing and reading each others minds and emotions because of communal child care. This probably sounds rather unconvincing when stated like that, but there are good arguments for taking Hrdy seriously.

All living great apes have rudiments of empathy and what philosophers like to call "theory of mind"-- kinowing that others can have thoughts different from your own. Humans, by the age of two, far outstrip captive-reared great apes in these mental abilities necessary for cooperation. Since great apes have rudiments of these abilities, we can assume that early humans did too. The question is, what caused strong selection in favour of increasing these abilities?

Cooperative breeding, a situation where some individuals forgo reproduction to help others rear offspring, has evolved independently in several species of insects, birds and mammals, and many times within primates alone. In other words, it's not hard to evolve into a cooperative breeder. Cooperative breeding also tends to evolve when the environment is harsh or unpredictable. The Pleistocene environment our ancestors lived in certainly was unpredictable, and Hrdy proposes that the lineage leading to humans evolved cooperative breeding.

Now we have some neural and genetic hardware for cooperative traits, and a novel communal rearing environment. As a result of being reared by multiple individuals instead of just Mum, offspring would develop mental abilities that had only existed as genetic potentials in the past. Natural selection cannot favour traits that are coded in DNA but aren't expressed in an individual's behaviour. So by exposing variation in capacities for empathy, cooperative breeding made it possible to also select for expanding these capacities, because the youngsters best able to persuade others to care for them, would be most likely to survive and pass on their abilities to engage with others.

One of the lovely things about this model, is that it provides a clear example of how intertwined "nature" and "nurture" are in evolution. Without some genetic capacity for empathy and social engagement, there would be no way for a novel rearing environment to extend the expression of such traits, and no way for the information to be passed to subsequent generations. Without the novel rearing environment, there would be nothing to select on or for genetic variation in the capacity to feel empathy.

Although Singer, Pinker and Hrdy have argued strongly for empathy being crucial for being nice to others, one could also point out that it is jolly useful in competitive contexts too. What better way to manipulate and deceive others for your own ends than to be able to read their minds and feelings? While humans, honeybees and meerkats are superb examples of cooperative breeding, conflict does occur within groups. Like most new technologies, cognitive tools such as theory of mind or empathy arguably extend our abilities to be both more cooperative and more competitive.

Wednesday, November 18, 2009

Comfort on the Origin

Creationists have been handing out free and glossy new copies of the Origin of Species in universities all over North America. This is apparently a cunning scheme to entice students into reading a 50 page introduction linking Darwin and his evolutionary ideas to Hitler. For the really funny bits, jump to "Solving Life’s Most Important Question" on pg41 and continue reading from there.

The august author of this thrilling introduction is none other than Ray Comfort, made famous by a short video in which he (in all seriousness) extols the domesticated Dole banana's divine design. This video has kept many undergraduate evolution classes entertained, particularly as Mr. Comfort's enthusiasm extends to descriptions and demonstrations of how "the banana" has been perfectly designed for "ease of entry into the human mouth", with a "non-slip surface". The fact that bananas in general, and Dole bananas in particular, have been bred and genetically modified by humans to acquire all these handy characteristics had escaped Mr. Comfort's notice (he has since apologised for the oversight). With such stunning credentials, Comfort is just the man to introduce Darwin's Origin. After all, he has all the necessary faith at his fingertips. If you aren't familiar with the Dole banana debut, here's a link:

The 50-page Comfort introduction is available online:
So is a rather feeble rebuttal by America's National Center for Science Education:

The Comfort introduction begins with a laughably banal section on Darwin's life, swiftly followed by an attempt to clarify Darwin's religious beliefs. No one, least of all Darwin himself (in his writings) is at all clear what Darwin's religious beliefs were, except that they changed rather often, and depended a lot on who he was writing to. A few quotes out of context doesn't shed much light on how Darwin defined a deity or his beliefs. Besides, what possible bearing does Darwin's religious beliefs at different points of his life have to do with evidence for evolution and natural selection?

After his little foray into Darwinian biography, Comfort attempts to explain how DNA constitutes evidence against evolution. The irony of this as a first salvo is almost painful, because the recent developments in genomics are arguably the best and most overwhelming evidence that all living things inherited their genetic code from a common ancestor. Living things simply have far more genes in common than anyone had imagined before they had genomes to compare. Every new genome adds hundreds and thousands of examples of the same genes, duplicated or tweaked slightly to serve new or modified functions, all coded in the same four DNA "letters".

Recognising this fact, Comfort suggests that an intelligent designer would know when something works, and use that design feature repeatedly, so of course lots of genes should be shared. There are two glaring counter-examples to this claim. Firstly, the genome (and natural diversity in general) abound with examples of convergence-- different solutions to the same functional problem. For instance, genetic changes conferring pesticide resistance have evolved independently in more than one species or population of pests. Secondly, there is plenty of evidence of unintelligent, suboptimal design in biology. For instance, genomes are full of DNA that seems to exist simply because it's good at persisting and replicating -- rather like computer viruses. Why would an intelligent designer add that?

Comfort trots out the beloved creationist argument that all this superb genomic complexity could never have come together by chance. Well who, other than creationists, tries to claim that? The whole point of evolution by natural selection, is cumulative change over time. Richard Dawkins is eloquent on this particular topic, so I won't belabour it.

Sadly, all the NCSE had to "rebutt" the notion that genomes arrived suddenly out of nothing, is that "This is not a scientific view of evolution", and "almost all scientists understand that complexity is not a problem for evolution". That's rather like saying the Pope understands that condoms are not a problem for Catholics. Rather than a claim that relies on faith, a sentence or reference with a decent counterargument would have sounded more scientific.

From DNA, Comfort moves to fossils. Why, he asks in separate sections, are there no good transitional forms, and why are there missing links? Those sound like the same question to me, and the answer is that there are plenty of transitional forms. Besides, the standard biologists' quip is that a new missing link only creates two more. And there is no good reason to expect transitional forms in the fossil record to look intermediate between the most closely related species still alive. You might expect the human ancestor to look half human half chimp -- Comfort seems to. But just look at birds. No one would have expected transitional forms in the ancestry of birds to lead to dinosaurs, but that is what the fossil record demonstrates, in abundance.

Admittedly, the fossil record isn't perfect, and events like the Cambrian Explosion are unusual. That doesn't mean that the Cambrian Explosion contradicts evolutionary theory. To quote an eminent evolutionary biologist, JBS Haldane, what the creationists really need is "fossil rabbits in the pre-Cambrian".

Finally, we get to "The Evolutionary Process" itself. Comfort trots out the usual creationist stand that microevolution (changes within species), is acceptable, and distinct from macroevolution (between species). As Darwin takes pains to emphasise in the Origin, there isn't really a point in time when you can stab a finger at a two varieties and say "look, separate species". Species are categories that we can define with hindsight, when populations have diverged enough to be reproductively isolated. Saying yes to evolution within but not between species is simply a retreat into a "God of the gaps" argument.

Mutations. Comfort seems to think that Darwin was au fait with the term, when the rudiments of genetics weren't incorporated into the evolutionary synthesis till the early 1900s. Yes, adaptation by natural selection does not require mutations to occur in the direction that favours the adaptation. That's the beauty of natural selection. It's a sieve, it keeps the variants (thanks to mutations and other processes like sex) that work, and the rest fail to replicate themselves. The variants don't have to be created in any directed way.

Evolution's Difficult Questions. This should make evolutionists quake in their boots. The first salvo is a devastating return to the notion of "irreducible complexity", the notion that you can't get to something as complex as an eye through little steps, because every bit of the structure has to be there for it to be of any use. A similar argument inferring design is far more eloquently expressed by Paley, one of Darwin's favourite writers when Darwin was reading theology at Cambridge. What Darwin did was to find an unconscious designer in the repetitive sieving algorithm of natural selection. The fact is, both poster children of irreducible complexity, the eye and, more recently, the intricate molecular motor known as the flagellum, have been repeatedly squished by evidence of transitional forms that do benefit the organism that has them.

Vestigial Organs. According to Comfort, these constitute evidence against evolution because it is "devolution". If Comfort had actually read and understood the book he is attempting to introduce, he should have noticed that evolution is not a directed or progressive process with a goal. Devolution is evolution.

Another Thought. This paragraph arguing for an intelligent designer because humans, intelligent as we are, still can't create something from nothing, is somewhat sudden. It also follows ironically on the heels of one of the best arguments against an intelligent designer. Why would an intelligent designer leave bits and pieces of useless vestiges in his creations?

And now for something completely different. Really from the ridiculous to the more ridiculous. Darwin's "Unsavory" Views. One wonders why Comfort even bothered with the inverted commas, he means it so literally. Criticising Darwin for the more unfortunate outcomes of "Social Darwinism" is like saying Jesus was evil because of the crusades. Darwin was unfortunate enough to have the movement named after him, but that is hardly a personal connection. Comfort also accuses Darwin of racism. By today's standards, all Victorians were racist. Darwin was an abolitionist, vehemently opposed to slavery, and he also viewed humans as a single species, something that was under great debate at the time. Comfort talks about not finding evidence that Darwin thought blacks and whites should be treated differently. He cunningly avoids mentioning that during the Beagle voyage, Darwin was appalled by the ill-treatement of a slave, and argued with his captain about this.

Charges of sexism come next on the list. Victorians were, by and large, sexist by today's standards. The brevity of this paragraph suggests a distinct lack of evidence, but Comfort does dredge up one of my favourite Darwin quotes "better than a dog anyhow", which is in the "Marry" column of a list Darwin compiled while deciding whether or not to marry. But to get back to the point, racism and sexism don't follow from evolution or natural selection.

His Famous Student. A long paragraph devoted to Hitler. Hurrah. As with the accusation of Social Darwinism, we have a spectacular leap from the person who proposes an idea, to an example of something nasty that has picked up bits of that idea. Hitler doesn't quote or mention Darwin by name in Mein Kampf. We could just as easily accuse Plato of proposing the notion of "ideals", and inspiring Hitler to create an ideal race.

The Hit List. "Just as he did with evolution, hitler [sic] also used Christianity for his own evil political ends." That is actually what Comfort writes. Why, then, is he only lambasting Darwin, and not every person involved in creating and modifying the Bible?

Darwin and Atheism. In addition to repeating a variety of misunderstandings, Comfort appears to view science and religious belief as democratic processes. He cites the depressing figures from a 2007 Newsweek poll, where "48 percent said God created humans in the present form at one time in the last 10,000 years or so, and another 30 percent believe God guided the process—so 78 percent attribute creation to God. only 13 percent believe in naturalistic evolution." Therefore, concludes Comfort, evolution is not true, and the creator wins. ???????
Possibly aware that readers are flagging at this point, Comfort adds "... please stay with me. I deeply care about you and where you will spend eternity."

Solving Life’s Most Important Question, is how Comfort tries to help us spend eternity in the right place. Would you like "the original Mona Lisa" or a parachute if you had to jump out of a plane? Apparently the plane is life, death is hell, the Mona Lisa is atheism, and a parachute is Christianity. "does that help you connect the dots?", asks Comfort. No.

The Leap. Assuming that one believes in an Old Testament God, this attempt at cross-questioning your conscience a la Spanish inquisition is positively pant-wetting. Well, if you thought that was frightening, things get better. We are told of "Little Jessica", a brutally raped and murdered 9-year old girl. "How do you react?", asks Comfort. Apparently any outrage you feel is a result of God's outrage, which is "evidence of his goodness." (italics Comfort's). I am surprised that Comfort doesn't even try to use evolution, atheism and Darwin as punchbags for all this outrage he's generated.

I'm rather surprised that Comfort's Almighty God is such a frightful Old Testament bogeyman. The next sections are titled "Instant Death", "Let's See" (how hopeless other major religions will be at saving you from hell), and "Back to the Plane", in which Jesus is stuck in to rescue us sinners from a very nasty crash. "Do it Today", urges Comfort. "Do it right now". Hang your faith on "Lord Jesus Christ" has you would hang your body on a parachute. Good luck.

Thursday, November 5, 2009

Cowboy days

The Four Corners, where New Mexico, Colorado, Utah and Arizona meet is the only spot where four US states meet. The meeting point itself is a rather dismal Navaho trading post covered in small stalls and parking spaces, but the region is simply stunning. Here are a smattering of photos-- gory details on Flickr.

Incidentally, if you are at all keen on American folk/country music, the album "Clean Shirt" by Waylon Jennings and Willie Nelson is superb.

Tent Rocks

Taos Pueblo

Forest fire on the way to Bryce CanyonBryce Canyon

Raven at the Painted Desert