Wednesday, September 28, 2011

Extinction and taxes

There's not actually very much evolution in Robert Frank's The Darwin Economy. Frank takes a big idea from Darwin: the insight that success is relative, and so how much is enough depends on what everyone else is doing. But the deeper you go into the book, the less Darwin is mentioned. (Also, this something that economists must have already realized, because they've got a name for it: positional spending.) Essentially, it's a book about tax policy, and a very good one.

I've got a piece in Slate criticizing his biological examples (and spinning off from there). But I thought the writing about economics was excellent, partly because I'm not an economist and it was all clear to me. Not everything he advocates chimed with my prior prejudices — he argues (convincingly), for example, that goods should be allocated on willingness to pay, even though that might see them go to those we consider less deserving. But it's hard not to think that the world would be a better place if Frank were making tax policy.

Frank makes the point that an arms race and a tragedy of the commons are the same thing. Everyone is better off if everyone shows restraint, but any individual is better off if he or she alone cheats. So the rational thing to do is cheat, and everyone ends up worse off.

This is a connection that biologists have only just begun to make. In particular, Hanna Kokko and her colleagues, including Daniel Rankin, have published a series of papers looking at whether and how a species might evolve itself to death, with selection for individual advantage leading to population collapse. (In a not-very-useful sense, every adaptation beyond being a string of RNA sitting in the primordial soup is a tragedy of the commons, because it diverts resources from reproduction in search of a competitive advantage.)

It's this connection that originally set me thinking about Frank's take on evolution, although, as is the way of these things, nothing of that ended up in the piece.

The main purpose of this post, then, is to make up for that by directing you to this very readable paper published in Oikos early this year, in which Kokko and Katja Heubel draw the link between tragedies of the commons, levels of selection (i.e. individual vs group) and sexual conflict (differing evolutionary interests between males and females).

As an example, they use a fish, the Amazon molly, so called not because of where it lives (Mexico/Texas), but because it's an all-female species. But even though it produces asexually, it still needs to mate with a male of a closely related molly species, to help things along developmentally.

The Amazon molly, then, is a sperm parasite, and the host species would be better off if males could resist the temptation to mate with them. Selection on individual males, however, usually tends towards indiscriminate keenness, because missing out on a genuine mating costs more than mating erroneously. So a tension between group and individual good is created. Can this, Kokko and Heubel ask, lead to prudent males? There's some evidence it can — males from population that coexist with Amazon mollys are choosier than those that don't.

Besides all that cool stuff, another reason I liked this paper is that it says this about the group selection debate:

Our second message is to remind researchers that much of the battle about levels of selection is ultimately about how we teach students about evolution. For some reason, most laymen who accept evolution think of natural selection as something that ensures the survival of a species. Student generation after student generation, bright young minds must be made aware of the flaws lurking in naïve group selection thinking before they can hope to argue clearly about evolution. …The mainstream approach of evolutionary biologists in dealing with this problem is to learn to label all ‘group’ arguments as inherently dodgy.

Given the number of dodgy arguments ever produced, this rule of thumb is often valid. Still, recent theoretical work creates the very valid question by any deeply thinking student: if kin and group selection really are two sides of the same coin, why is one ‘good’ and the other ‘bad’ in our textbooks? The crux of the issue seems to be no particular scientific result, but the fact that for some unknown reason it is much more natural for people to come up with naïve (wrong) group selection arguments than naïve (wrong) kin selection arguments, and evolutionary biologists consequently have to be trained to be very wary of the former. … However, among experts, it might be time to move on from petty semantics to a true appreciation of demographic consequences of cooperation and conflict, and the rich tapestry of evolutionary outcomes that can arise over different time scales, whichever the favoured mathematical method each person chooses to employ.

Which seems a very useful way of looking at it.

Thursday, September 15, 2011

How reputation can (help, in a small way, to) save the world

Nature Climate Change has just published a comment piece by me looking at the role reputation can play in achieving some sort of action on climate change. But hey, seeing as it'll cost non-subscribers $18 to read it, why not save yourself 87 cents and pre-order my book instead? Most of it's in there, and you'll get approximately 78,500 other words thrown in at no extra charge.

Reputation is fantastic at solving collective action problems. Climate change is the biggest collective action problem in our species' history. So what can reputation do to address climate change? At an individual level, perhaps a bit - there seem to be reputational rewards from shopping green, and from climate-conscious generosity. That said, conspicuous consumption is always likely to be a more reliable status symbol than conspicuous non-consumption.

But me not taking leisure flights (which I haven't for a few years) is not going to stop China building coal-fired power stations. So how do we get international agreement to limit emissions? The world of international relations has been described as one of anarchy and self-help. And yet, most countries honor most of their treaties, most of the time. In the absence of the world government that isn't going to happen any time soon, concern for their reputations is one of the things that makes them do so. (I am a fan of UC Berkeley law professor Andrew Guzman's papers on this topic.)

Unfortunately, Guzman (I think it was him) has written that reputation seems to work best at encouraging compliance in areas that aren't central to a country's interests, such as nature conservation. I don't think we can really put the transition to a low-carbon economy in that category. The higher the stakes, the greater the temptation to break the rules (I think the Dutch football team's behaviour in the last world cup final is a great example of this.)

And it works best when there's also domestic pressure on the government to behave well. Which is missing at the moment. And unlike people, countries rarely treat each other in one area based on how they behaved in another - rather, they have lots of different reputations.

So in terms of avoiding a global tragedy of the commons, most of what's in our social nature is still pointing the wrong way. I'm still hoping for some moral leadership to come from somewhere. But I'm not hopeful.

Tuesday, September 06, 2011

Bruce Chatwin's evolutionary biology

I started reading The Songlines in the belief that it was a travel book. And it is, and for a while that's all it is — Bruce Chatwin's book, published in 1987, is primarily about his time in the Australian desert with Aborigines and the people who work with them.

But about a third of the way in, it starts getting evolutionary, with a sudden digression to recall a visit to Konrad Lorenz in 1974 (I think he was interviewing Lorenz for the Sunday Times.). Chatwin goes to Lorenz's family home in Altenberg, just outside Vienna (a place I have visited in its current incarnation as the Konrad Lorenz Institute for Evolution and Cognition Research; I don't think it's appearance has changed much).

The memory is triggered when Chatwin sees an Aborigine act out the travels of the Lizard Ancestor, reminding him of Lorenz's own ability to mimic the animals he studied. For anyone wonkish about animal behaviour, this chapter is worth the price of admission alone. But it is also a jumping off point, from where Chatwin goes into Lorenz's ideas about aggression in and human animal nature. From then on the book is increasingly devoted to Chatwin's own ideas about human evolution.

Chatwin was not a complete amateur in this regard. In the mid 1960s, he abandoned a job as an auctioneer at Sotheby's and went off to do a PhD in archaeology at Edinburgh, which e also dropped out of after two years. There's lots in The Songlines about his visits to important palaeoanthropological sites, especially in South Africa, where he spends time with Raymond Dart and Elisabeth Vrba. He also planned a sort-of-academic book about nomads that he never completed, and large sections of Songlines is given over to fragments from those notebooks, along with quotes, reminiscence, anecdote, and so on (much of which teeters on the verge of outrageous padding).

Chatwin's big idea about human evolution is that predators — or The Beast, as he calls it — provided the selection pressure that made our species smart and social. Out on the savannah, he thinks, the carnivores, especially big cats such as Dinofelis, were so menacing that it was adapt-or-die, and in our case adaptation meant becoming human.

Chatwin runs this idea past Lorenz: "[He] tugged at his beard, gave me a searching look and said, ironically or not I'll ever know:
'What you have just said is totally new'."

I say: baboons*.

Chatwin's ideas about The Beast led him to believe that the violence in our natures arose not for competing with each other, but for defending ourselves against predators. And his travels among nomads lead him to believe that settlements, institutions, states and so on pervert our natures so as to bring out the worst in us. That is to say, he thinks that humanity's natural and good state is to be like Bruce Chatwin.

There's nothing wrong with this just-so-storifying, and he's far from the first or last person to come up with a scientific hypothesis that's comfortingly close to his own temperament. I don't think Chatwin's ideas on human evolution have aged very well —if I had to sum up what evolution has done to human behaviour, I'd say it has made us better at cooperating with members of our own group, the better to compete with members of other groups. (See for example, to pick a couple of examples off the top of my head, the work of Sam Bowles and Robin Dunbar.) And humans seem the most likely culprits for the extinction of Dinofelis, and a host of other large vertebrates, not least in Australia. But this isn't a paper, and he's not an academic, so he doesn't have to meet the standards of academia. (Rather, he shows what you can get away with if you've got a fine prose style and the intellectual confidence that goes with being posh.)

I think Chatwin's 1977 travel book, In Patagonia is more successful, but I'm glad I read the Songlines, particularly for its descriptions (the accuracy of which I'm not qualified to judge) of how songlines work, and how Aboriginal Australians use them. Between the lines, there's also much that speaks to more orthodox ideas about human nature in how these groups coexist with one another, even though they are potential competitors for resources.

And one notebook fragment touched a nerve with me. A much-cited Bedouin proverb goes: "I against my brother, my brothers and me against my cousins, then my cousins and I against strangers." This is often, and correctly, given as an illustration of how people instinctively grasp kin selection.

But Chatwin's version adds another line: I against my brother, I and my brother against our cousin, I my brother and cousin against the neighbours, all of us against the foreigner.

What made me so happy about this is that it shows that social distance and genetic distance are equivalent, because they are both a measure of shared interests, and so influence the benefits of cooperation versus competition. Ideas about social distance are a theme of my reputation book, and one that no doubt/I hope I'll be developing here in future posts


*That is, a smart-but-not-that-smart level of group solidarity and some nasty canines seem quite adequate for dealing with large carnivores.