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

Tuesday, March 22, 2005

Design continued: A tale of two knives

Suppose I present you with two objects. One is a Toledo blade, made from Wootz steel (which, it turns out, was actually made in south India by families who guarded the secret of its manufacture. Even today we know its composition but not the way it was manufactured, exactly, although there are enthusiasts who are reinventing techniques, possibly not the same ones, to make equivalent steel).

The other is a stone knife, or seems to be, made from chert around 6,000 years ago.

What can we infer about the objects? Well, it may seem obvious that they both are made by design or intent. But it is possible that a suitably primitive stone knife is indistinguishable from an accidental flake of chert caused by another falling rock hitting a cliff face. There is no seemingly plausible account of the Toledo sword being made by unintentional processes.

Why can we reliably infer design in the case of the sword and not the stone knife? Let us consider some reasons:

1. We have a historical record of Toledo blades, but not of stone knives. Well, yes, this is true, but if we came across one for the first time, with no prior record or knowledge or Toledo blades, Damascene steel, or even human warfare, we'd likely conlude it was made by technologically sophisticated manufacturers, and that it was designed to do its job - either by the sword maker or by a tradition of sword making to which the maker was heir. It doesn't matter if the designer is a single individual or a tradition here.

2. The complexity of the structure is not producible by any known natural (i.e., non-artificial) process, while it is known to be the sort of thing humans make. Complexity alone is not sufficient as an indicator of design, despite the assertions of the IDevotees. Many natural things are complex (in particular, the microstructure of minerals and crystals). But as we uncover more about the natural world, we get an increasingly clearer idea of what the natural world can produce, and very surprising it is too. The usual argument for ID is based on an argument from incredulity, as Dawkins calls it, or a failure of imagination.

3. We know the function of swords in human culture. We also know the function of stones with sharp edges, but unless there is some sort of complexity (flaking patterns on the edges) that could only feasibly be produced by humans, we can't tell if it is a natural or an artificial product.

Are you starting to see a pattern here? We can tell if it is designed only if we know the sorts (classes) of things that designers produce, and the classes of things produced in the natural world without design, and the instance in question is in one but not the other.

Incoherent theories: Our ancestors were the smartest...

An Indian blogger and respondent named Manjunatha has further comments in his own blog Incoherent theories: Our ancestors were the smartest... about the reasons why evolution was proposed by Europeans and not by the Hindu tradition.

It's an interesting suggestion - Europeans developed a theory of evolution because they thought they were naturally better than everyone else, and the theory supported that. In short, because they were racist.

Manjunatha doesn't make the genetic fallacy error here - he's not doing the usual foolishness of those who dislike evolution (he doesn't, for a start) by thinking it is tainted by its origins. In fact he seems to think this is a matter of social conditions that made it possible to discover not only evolution, but other science.

Is this true? Well, yes, partially. Evolution (the idea that things change over time) was developed by a temporalisation of the Great Chain of Being, which was "progressionist" in that the scale of nature rose from simple and primitive to complex and "civilised", and of course, Europeans were at the top of that ladder in the 18th century, so they thought. So the first kind of evolutionary theory was indeed racist, since it implied that Europeans evolved last, or, in Lamarck's scheme, that their independent lineage began evolving first, and were thus "highest".

But did this mean India could not have developed it themselves? I don't think so. A group of thinkers known as the Charvarkas (or Carvarkas) were as materialistic in their way as the Epicureans. And they lived at the beginning of the Vedic period. I think, though, that the reason India never came up with this idea is pretty obvious - they didn't develop a scientific endeavor. Science evolved once - in Europe. And even so it took another 250 years for a proper theory of evolution to be developed in that tradition. In short, while being racist may have set up the preconditions for science to approach the topic, and even made legitimate a few of the eventually adopted ideas, I don't think that racism is the key - science is the key. Had India developed a full-blown scientific tradition, then they may have come up with it first, or independently.

And I don't think Europe was any more "racist" than any other ethnic group in political and military ascendancy, and particularly not India, which seems to have fossilized its racism into the Varna caste system.

Monday, March 21, 2005

The creationism of the Vedas

From New Humanist January 2005:
Under BJP rule, superstitions started getting described as science. Hindu nationalists started invoking science in just about every speech and policy statement. But while they uttered the word ‘science’ — which in today’s world is understood as modern science — they meant astrology, or vastu, or Vedic creationism, or transcendental meditation or ancient humoral theory of disease taught by Ayuerveda. This was not just talk: state universities and colleges got big grants from the government to offer post–graduate degrees, including PhDs in astrology; research in vastu shastra, meditation, faith–healing, cow–urine and priest–craft was promoted with substantial injections of public money.
Prayers to smallpox goddesses, menstrual taboos, Hindu nature ethics which derive from orthodox ideas about prakriti or shakti, and even the varna order were defended as rational (even superior) solutions to the cultural and ecological crises of modernity.
"Varna order" is the Hindu caste system.

Hindu creationism/antievolutionism is well-established. See Sri Swami Sivananda's book for an example. The Vedas say the universe is milions of billions of years old, and humans are billions of years old. Again, science is twisted to serve religious ends. Michael Cremo, author of Forbidden Archeology has just released his Human Devolution.

[A passing note worth remarking upon. It isn't just Christians or Muslims. Anti-modernism is everywhere.]

Sunday, March 20, 2005

Design and explanation

Let's think for a second about explaining how things happen or why.

When we give an explanation of something - philosophers refer to it as the explanandum, the thing to be explained - what is it we are doing? There are a number of accounts in play, but in science, I believe the nomological-deductive (ND) model or "covering law" model and its variants is the best account. Another account is the causal mechanism account in which something is explained if a causal mechanism is offered that is sufficient to cause the explanandum - I have no major objections to this, but I think it can be accommodated in the ND view. A third, as given in the above link, is the "unificationist" account, which is pretty well a "winner takes all" view that owes a lot to evolutionary epistemology, so let's leave it to one side for fear of question-begging.

Under the ND model, explanation is given when something like the following is successfully offered:
M. Model, law or generalisation
C. Initial and boundary conditions
E. Thing (phenomenon or process) to be explained
The "sum" here is a relationship whereby M + C make E likely, or determinate. If M, C and E are all statements representing the states of affairs, then the outcome is to make E true or very likely to be true. It is usually put, since explanation is an act of knowledge, as an inferential relation. Hempel's original version had it as a deductive relationship, but probabilistic and statistical accounts were very soon forthcoming, from him and others.

Okay, enough arcane stuff. Let's consider how we might explain the existence in bats of a membrane between their phalanges that enable them to fly. Evolutionary explanations would run like this:

M. In environment E, if Trait T is fitness-enhancing, T will become fixed or widespread at an equilibrium in the population P
C. [Bat ancestors were in E, had membraneous inter-phalangeal T and T was fitness-enhancing in P]
E. Modern bats have T
Notice something here - the conditions C are not available to us. We do not know what conditions bats were in, and we do not know whether in fact having membranes between the phalanges increased fitness. This is something we infer. In fact, it is something we predict. If we ever find a basal bat fossil, we expect it will have partial membranes and will be, on one account anyway, an arboreal creature, like sugarglider possums and flying squirrels are today.

An explanation allows us to make predictions. If the model M has exceptions, then we are able to refine or extend the model to enhance our knowledge and explanatory ability. This process is called scientific progress. Suppose we find that there are animals that routinely have a fitness-enhancing trait that do not end up at fixation or equilibrium.

Now, how would we explain an E with a design model? Let's take two cases - one where we know that a thing was designed, but not how (the Toledo steel used in the blades), and one in which we know how a thing might be designed, but not that it as. [In the next blog entry, that is.]