Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Saturday, May 13, 2006

Evolution and truth

One of the problems in having a philosophy related blog is that ideas are hard things to generate on demand, so often you need someone to raise the problems for you to think about. Being naturally (and preternaturally!) lazy, I don't go out looking for problems (of a philosophical nature; the ordinary kind seem to find me like flies find rotting garbage). Hence, this blog is sporadic.

Well, I just tripped over an interesting question raised by Certain Doubts: can we reconcile the Platonic value of truth with an evolutionary view of epistemology? That is, if we think that our knowledge is the outcome of evolution (which I do), can we still think that knowledge is about the getting of truth? Absolute truth, that is, not the purely "good enough for government work" kind that we all rely upon in daily life.

The conundrum is this: evolution (natural selection, anyway) serves only to optimise that which is satisfactory to the past environments of the organism's ancestors. To use a memorable phrase of Hull's, evolution is like the Prussian military academy that turns out officers admirably suited to winning past wars. But our cognitive capacities were not designed to deal with such matters as subatomic physics, comparative biology, or risk analysis in complex economic systems. We were designed to deal with living in certain environments and social groupings that we no longer mostly live in, and the ideal of truth-gathering is well out of that environment. In short, can we trust modified monkey brains, as Darwin posed in another context?

One way to rescue some form of naturalised epistemology f this kind might be to say that we can rely upon our native cognition in cases where they are closely similar to those ancestral conditions, whatever they might have been. But even this fails, since evolution is not, generally speaking, a global optimiser, but a general satisficer. That is, so long as the animal is viable enough, relative to other candidates, then it will procreate its kinds. Some sort of induction is good enough for hominids in their usual environment - as Quine said, "Creatures inveterately wrong in their inductions have a pathetic, but praiseworthy, tendency to die before reproducing their kind". I don't know about the praiseworthiness, which remains to be seen, but Quine's claim was that we have an innate "quality space" honed by selection, which refers because it works.

There's an obvious problem with this, or rather, several obvious problems. First of all, we often make mistakes. The problems of optical illusions have a long history in philosophy of indicating the unreliability of vision, and similar issues arise with our cognition. We are very bad at deductive reasoning, for example, when the variables are abstract or unnatural, as the Wason test shows. We are bad at risk assessment - people are afraid of flying but not of riding in a car, although you have a much higher danger of death or injury in cars than planes. We fear home invaders far more than family, although you are more likely to be attacked by a family member than a stranger, and so on. Our cognitive skills are based on whether or not they contribute to reproduction rather than individual knowledge. Evolution, if we envisage it as a designer, cares nothing for truth, just progeny.

Another problem is that our quality spaces are, if they exist from evolution, very domain specific. While it explains why we have a priori concepts - Kant's synthetic a prioria are evolutionary a posterioria, as Lorenz said - it doesn't guarantee their applicability outside those domains. A third problem is the one of satisfaction; if a concept works most of the time, it doesn't make it reliable all the time, just satisfactory so far. Consider what will be better - the ability to spot a predator if and only if there is a predator, or a jumpiness that works most of the time if there is a predator, but also makes us jump at sudden noises and shadows. There is a cognitive cost to being right all the time, and evolution won't burden us with an expensive solution that in any case would take time to employ, while the leopard is leaping at your throat. Better to startle and run, and be embarrassed, than to be right and dead.

So, can we have absolute truth and natural evolved cognition? I think, as Putnam said, that evolutionary epistemology fails to explain the core problems of epistemology. Or does it?

We often focus on individual cognition as the locus of selection, and in one way this is right, because we are considering the reason we have big brains, and the cognitive apparatus they make possible. But there is another level of analysis - that of the tradition or culture. These, too, evolve, only not biologically but culturally. A society that learns how to use local resources to flourish has knowledge even if the "explanations" given involve ritual magic or religious etiology. It doesn't matter how the efficacy of Amazonian poisons derived from frogs is explained by the local tribes - it matters that the tribes know that it works.

But that brings with it implications of the magical explanations, and so on, which are formed largely in the context not of the physical world as such, but the social world in which explanations asked and offered play functional roles in establishing and maintaining social structure. In short, these explanations are not about adapting to the "world" but to "society". And throughout human history, such cultural evolution has been both minimally adaptive in a given environment (or not, as in the Anasazi case where they overexploited local resources), allowing the society to remain viable, and adaptive in social functional terms allowing agents within the culture to interact in various ways. What it does not do is offer truth, or if it does, this is a truth of pragmatic virtue and convention.

But around 1700 or so, a movement finally took off in which several factors combined to permit human cognition to overcome the limitations of biology and society to an extent. In this movement, specialisation ensured that the explanations given were satisfactory in each domain to those who were best acquainted with the material. It recorded the work in detail, and made a virtue of discovery and theory. I am talking about science, of course.

The prior commitment to Platonic or Aristotelian truth had, in 2000 years, made almost no progress of any real kind. While the logical and theological domains were transformed, actual knowledge of the extra-social world was thin on the ground. When advances were made that did relate to physical facts, such as engineering and manufacturing technologies, before this point, they could easily be lost because that knowledge was held only by a small family tradition or a guild that might be banned or become uneconomic at any time. Yes, truth was a virtue, but one more honoured in the breech than the observance.

It wasn't even enough to be empirical. Many, such as Roger Bacon, Nicholas Oresme, Frederick II, and others had done good empirical observation in the middle ages, but the habit didn't take. With the appearance (in fact the evolution) of specialisation and above all communication of results and the availability of the records to all, science took on the role of cognitive system. Subsequent adaptation of scientific institutions made it more able to generate knowledge than at any time in human existence.

But what is science adapting to, exactly? A naive answer might be that it is adapting to the data. This is a nice simple answer - we can rely upon science because hypotheses are tested and proven (in the Old English sense of "proven", meaning well tested and found reliable, as in the "exception that proves the rule" by testing it). Add a dash of falsificationism, and you are on your way. I think this is grossly mistaken.

Science is adapting to the real world, in some manner. It might help to think of it like this - a model builder invites you to guess what he has made, but it has a sheet of some thickness over it. You can see the points that support the sheet well enough, but the identifying details are hidden behind the cover. How can you find out what it is? You have a stick to poke it with, and ten seconds. Go...

Well, it's a large model, and in ten seconds you can't feel all of it, so you poke at the supported bits in the hope that the shape will become clear. At the end of ten seconds, you guess that it's a model of some guttering. It's actually the Vallis Marinaris on Mars.

Science, like you, has a limit on what it can measure, and there's a a cost to that activity, so some conceptual triage is needed. If something is measured, then within measurement error you have knowledge of that data point alone. The rest is inference, interpolation and generalisation. How do you choose what to measure, and what to infer? Some of these choices are influenced by your personal dispositions and predilections, some by the conventions of the discipline. Others are mostly due to social context, government policies, religious beliefs, and so on. Science has some social functional adaptation after all.

This has led some to claim that science is just another worldview, a claim seized upon by antiscience movements like creationism and intelligent designism. But it isn't. Is is not just another worldview. It is an enterprise that is parallel to worldviews, creates worldviews, and shares a multiplicity of disparate worldviews amongst its practitioners. Worldviews aren't what makes science special.

What makes it special is that the institutions themselves tend to make claims that can be challenged and do get challenged, if there is any reason to. And given that the resources of science as limited like any other, there is always reason to do so. Of course, not everything gets tested in the usual sense, but there is sufficient selection for consonance with prior work, for empirical adequacy, for explanatory power and the ability to generate research programs, that in the medium to longer term, science generates pretty adapted results. Adapted to the empirical world, that is.

I can think of some constraints on science, though. One is, and I haven't seen this discussed anywhere so You Heard It Here First™ unless you didn't, that science cannot progress beyond the ability to teach the next generation how to proceed. If something requires a depth of study that is going to take fifty years to learn, it will be abandoned in favour of either some other more rapid payoff to the individual's career, or the field will be divided into more manageable chunks. What can't be, won't be investigated at all.

So science is not absolute truth. Is it truth at all? Are we being objective here? Who knows? But a truth that is unattainable is not a truth that does much hard work. If the truth we can get through science works enough, that's the best we can hope for. Fortunately we got sufficient of a leg up from evolution to get started, and fortunately we did get started. But the Platonic ideal of truth is a dream of a reality we will never get access to, and is thus an item of religious faith not needed.

Novelist reinvents ethology

Tom Wolfe, whose works often show a considerable pretentiousness in my opinion, has a piece in the New York Sun entitled "Darwin meets his match". In this he adduces Zola and Weber, and most of all the 1950s American sociologists whose works stressed status seeking and display, to show that there is something missing from Darwinian theory.

Like social dominance ethology and psychology never happened, right? Darwin talked about social dominance and submission several times, and much of Weber's dialectic comes from the tradition of social psychology one might suggest Darwin was influential in creating, if not being the originator (Hobbes has that honour in my view). The ethology of Lorenz and Tinbergen, and the creation of social dominance theory among various species (not often applied to our own species, although the sociobiologists of the 1970s tried, such as Lionel Fox and Robin Tiger, but were shouted down as being neofascists), explained how social animals form dominance hierarchies, and the theoretical apparatus of honest advertising (costly, and therefore hard to fake) of status explained why animals "spend" status advertising the way they do, from the peacock's tail through to conspicuous consumption of potlatch feasts.

What I especially object to here is Wolfe's implication that somehow evolutionary theory is inadequate to this task of social explanation. But the theoretical infrastructure of modern evolution not only is adequate to it, it requires it. If the fitness of an individual depends upon his or her (or its) position in the social group, then he/she/it will need to be able to badge that status to those from whom the organism is seeking aid or mating opportunities.

Humans are social animals. This is a point noted since Aristotle. We form social dominance hierarchies. But unlike many organisms, which have a single, often nontransitive, hierarchy, we humans are able to set up and maintain our status on several hierarchies at once. I suspect this is because we are (i) mobile, and can interact with different geographical bands of humans through trade, warfare, intermarriage and cultural exchange, and (ii) we are able to abstract and communicate status verbally. Yes, Tom, language is important, but you are wide of the mark if you think there is no work done on when we evolved it. The likelihood is that it evolved around 200,000 years ago in its present form.

So we have a rank hierarchy for our own tribe or community, as well as hierarchies of age cohorts, ethnic groups, and within-gender hierarchies (come on - you didn't think that jewellery or bling was to impress the opposite sex, did you?). We also have a rather more obvious hierarchy in sedentary urbanised cultures - class hierarchies. So what will the average human do to maximise his/her/its* status? Each individual will strive to maximise fitness on a vector sum of these hierarchical scales, based on the physical traits and inherited wealth they have at birth and maturation. It may pay to get much money irrespective of physical attractiveness (the Trump ploy), but mostly it pays to come to an optimal tradeoff. You might find it best to be the top dog in your class, or your ethnic group. You might find that aggression works for you. Or it might be that being a middle manager in a middle class is the best outcome for you.

We use status to increase our fitness, but it doesn't follow that this equates to mating opportunities. It may be that your inclusive kin benefit from being a warrior who dies. It may be that having status vicariously will mean others in your tribe or troop will look after the progeny who are left behind. Or it may be that favours are returned, and because Uncle Fred died in the War (a sacrifice to the common good), his nephew is helped through hard times. All that counts from an evolutionary perspective is that one's inclusive fitness is improved.

One point that is often overlooked when discussing this sort of thing, is that it means that our biological dispositions created modern society. Evolutionary psychologists often say that our evolved dispositions are maladaptive in modern society. I find that hard to accept - we are in our "natural environment", because we made it. So we ought to go looking for the adaptive benefit of our general tendencies in urbanised agrarian societies, and not naively assume that if only we lived like foragers of yore, we would all be much happier. Perhaps we would if things went well. But have a population explosion, or a change of climate, and we would be damned unhappy. I read recently that "traditional" forager societies have a murder rate around 2-5% over an adult lifetime. That's much worse than New York during the 1980s.

Wolfe's essay is entertaining, and has some nice case examples, but it's not exactly news...

Friday, May 12, 2006

They call him the Decider

The US has an endangered species day

or so I found out from Grrlscientist. Given the extreme focus of US conservation policies on individual species, and the Endangered Species Act itself, now under attack from conservatives, I suppose this is a good thing. But one wonders, when will they have National Endangered Ecosystems Day?

They'd need to have it every week, I should think.

Hybrids in the news

I have a long standing interest in hybridisation, one that appeared out of nowhere after I read Jan Sapp's Evolution by Association, which is about another intuition-breaking aspect of evolution, symbiosis.

Hybridisation as an explanation of biodiversity goes back at least to Aristotle's History of Animals (Bk VIII, ch 28).

As a general rule, wild animals are at their wildest in Asia, at their boldest in Europe, and most diverse in form in Libya; in fact, there is an old saying, ‘Always something fresh in Libya.’

It would appear that in that country animals of diverse species meet, on account of the rainless climate, at the watering-places, and there pair together; and that such pairs will often breed if they be nearly of the same size and have periods of gestation of the same length. For it is said that they are tamed down in their behaviour towards each other by extremity of thirst.
"Libya" is the name for Africa, from the Hellene perspective, of course. Aristotle had another long standing account of biodiversity too - the effects of local water, soil and climate. This view wasn't abandoned until the early years of the 20th century. But it's hybrids that fascinate me and motivate this post.

Hybrids were accepted as a way to "fill in" the empty territory of the Great Chain all through the middle ages, through the renaissance and Reformation, by the translators of the King James Bible, and even by Linnaeus, the champion of species fixity. Mendel was in part attempting to work out how hybridisation generated the material for evolution, at a suggestion of von Nägeli, who was in effect his scientific mentor.

Oddly, though, hybridisation plays a largely negative role in modern evolutionary thought - a species is defined by its inability to hybridise, according to the Mayrian hegemony, at any rate. More positive conceptions like the Recogniton Concept or the Genetic Cluster concept focus on the cohesion of species rather than the isolation between them.

So I am going to post, whenever I become aware of a case, instances of hybridisation, both as a counterexample to the Mayrian Reproductive Isolation Conception of Species, and as an example of a process that we tend to overlook and which needs more attention.

The inaugural example is a hybrid between a grizzly bear father and a polar bear mother, taken from a note on John Hawk's site. It is often the case that when a species is stressed ecologically, and members find it hard to find mates of their own species, they will attempt to mate with closely related species. This has been seen with lions and tigers, ducks, and wolves and coyotes, to mention just a few cases. I wonder if this might be due to the warming effect reducing the hunting territories of the polar bear. The polar bear is sometimes regarded as a subspecies of the Brown Bear of which the grizzly, kodiak and Mexican Brown Bear are subspecies, though, so this might be just a case of introgression between locally adapted members of the same species.

Tuesday, May 09, 2006

A model scientific paper

Here is a model paper, the very paradigm of what a scientific paper should be...

Did the Neandertals jump, or were they pushed?

John Hawks is involved in a bit of a stir by suggesting that there was little or no overlap between sapiens and neanderthalensis occupation in the Near East and Europe. A Yahoo report today gives the claims of those for and against the idea of there being little overlap. It seems that Aurignacian culture, which ended around 29,000ybp, may have been Neandertal, rather than modern human. This may also put a dent in the view some have that Neandertals and modern humans interbred, although I gather that is not a popular hypothesis anyway. Fun to watch from the sidelines...

Monday, May 08, 2006

Poor creation scientists

Click on the comic to see it at home.

Sunday, May 07, 2006

The evolution of lawns

PZ Noun laments the need to mow his lawn. So do we all (I have a Darwinian view of gardening - anything that can survive my tender ministrations deserves to be there. I once killed a cactus by under-watering. I have a shriveled black thumb). But nobody asks the obvious question: why do we have lawns at all?

I have a theory. It is mine (ahem). Consider what lawns are - they are composed of early colonising plants that typically grow in patches of recently cleared ground. Later, longer grasses take over, and if the conditions are right, and there are no grazing animals, trees and forests. So it takes a considerable amount of energy to maintain a lawn. Why would we do this?

The English had lawns of camomile and herbs in the middle ages. Grass lawns began as part of the seventeenth century fashion, out of Italy, France and England, of bordered and hedged gardens, which were made by the rich aristocracy, who had plenty of land around their manors and palaces. A mown lawn was an indicator of wealth, disposable land, and servants to do the scything before mowers were invented in 1830. So it became the fashion for the middle classes, who were on the rise at the time in terms of wealth, to emulate the aristocracy. Lawns became particularly an English passion, and from there to America and the Commonwealth.

Why would we have lawns? To display our wealth and status. In other words, to behave as social dominance behaving apes. And the use of land is particularly interesting. We evolved as territorial nomads, not as landholders. What made us landholders was the coevolution of agriculture. When you spent most of your time sowing and nurturing crops, you needed to defend your territory (Rindos 1984), which gave rise to a warrior class from whom the rulers were chosen or arose through might and alliances.

One of the things that such wealthy rulers do is display their status through conspicuous consumption. Lawns were a case of "honest advertising" in that respect. Having land meant that you controlled power, such as military might, and could waste perfectly useful crop fields for a useless product that had nothing to recommend it other than it looked good.

Lawns also take an inordinate amount of water. In arid countries and places like Australia and the south western United States, to waste that much water is another signal of wealth. Of course, this requires that the signal is both differentially available (if everyone can grow one, it's not that much of a status symbol), and of course that the water is freely available. Unfortunately, now that the fashion is ensconced in our culture, we can't continue to do this, so the social selection pressure with rise to have them to display wealth. So something is going to have to give.

And none of that even begins to address the problem of ecosystems for native animals. PZ Thingy needs to grow his prairie.

Rindos, David (1984), The origins of agriculture: an evolutionary perspective. Orlando: Academic Press.

Late edit - south eastern to south western, as per reader's edit in comments.

Rick Pombo - the Gnostic gospeller of "wise use"

Here is an interesting item at Counterpunch on the anti-environmentalist Senator Representative Rick Pombo (R, CA). An opponent of the Environmental Species Act, Pombo wrote a book described here as "the book acquired the allure of a Gnostic gospel among the "Wise Use" crowd, whose concept of wise use derives from God's commandment to Adam in the book of Genesis to pillage the earth's natural resources as he thinks fit." Again, the use of religion by conservatives to support exploitation, in this case of ecological systems, for profit shines through.

Once upon a time "conservative" meant "one who desires to keep things stable". Now it means "one who tries to take whatever can be took". It's a peculiarly American definition of "conservative".