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, March 19, 2005

The magical designer

Well, I'm trying to do my work, but the creative juices aren't flowing right now, so let's get back to design.

Let's ask two questions here. One: What is design? Two: What is an explanation, such that design explains something?

To the first: when some person designs an object, they typically have several features as designers. They have a plan or intention, they have the competence to make that plan work, and they have the tools to implement the plan.

Plans don't generally pop up out of thin air. The most inspired of people have usually, if not always, spent years learning and pondering, trying out variations, and so on. As Pasteur said, chance favours the prepared mind. Artists train for years in older styles and techniques before they can make the break and move to novel ones of their own devising. Even what looks like random splatter, as in Jackson Pollock's Blue Poles, is the end result of years of experimentation. Plans get developed by inheritance of prior technique and goals, and by trial and error.

So, too, the competence. Anyone who trained in any art or skill knows that you don't do it easily at first, or well, but that you need to practice, identify your mistakes (or more likely have them identified for you by one who has already achieved proficiency), and correct them. Competence is the outcome of trial and error.

Tools and techniques in the manufacture (the word once meant "the doing of the hands") of designed objects are themselves the end result of a long period of cultural and technological development. One cannot make, say, a Toledo blade sword, without the knowledge of what materials to use, how to assemble and treat them, and the tools to cast and sharpen them. This is itself the end result of a process of, you guessed, trial and error, at the level fo the tradition, guild or community.

So ordinary design, the design we do know something about, and which features in our explanations of artifacts, is the end result of trial and error processes, which the American psychologist Donald Campbell called "variation and selective retention". He did this in direct parallel to a process of natural selection, and he added one more adjective - "blind". The variation cannot, ex hypothesi, be directed, because we do not know ahead of time what will work. So, we work blind, applying what we used before and making, deliberately or not, small changes to our techniques which may, or may not, work out. We make these variations in many ways. We try them out in our mind's eye, and reject those that seem wrong to us (based on the past). Sometimes this is not useful. We may discard approaches that could have worked very well indeed. But we will never know this, and the "space" of all possible variations is so vast that we just cannot try them all out.

Then we try the seemingly viable variations out in practice. Often we will start, and stop when it seems to be going wrong. This may also mean we miss out on good tricks. Again, the space of all variations is vast. We could also waste our lives trying everything. Then, if they work in a small scale, we will attempt to see if they work well in the wild, so to speak. If people find them useful swords or pleasing paintings. Then, we have advanced our tradition beyond where it once was. Thus is progress made.

Could it be that genius can sidestep this trial and error? I doubt it. Even the greatest of geniuses have, in their fields, studied. They may have a more creative mind, or be especially well-adapted to making bold moves that turn out to work, but before the event, they are indistinguishable from the many creative and bold folk who will eventually fail.

So I am going to make a declaration here; a principle of design, if you will. Call it Wilkins' Design Desideratum: any successful design is the outcome of past experience and trials.

Next, we'll consider how design is used in explanation.

Creationism and viruses

No, not the obvious memetic point that creationism is a virus of the mind, but that evolutionary theory can do things of importance in health issues - here the evolution of HIV - while intelligent design and creationism say nothing novel or helpful. From Carl Zimmer's Loom blog.

Wednesday, March 16, 2005

What actually is "design"

I've been wondering of late what it is that is explained when something is called "designed". The older design theorists had no such trouble - Aquinas, for example, noted that
... things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. [Summa, 1Q2.iii]
This is a wonder of spare and elegant prose, as always with Aquinas. Modern readers may miss the "has an end" and the meaning of "fortuitously". Something has an end if it is for that reason it does whatever it does. And something is fortuitous if it does not happen by necessity. These are old, Aristotelian, categories of metaphysics. It is my opinion that they were developed by Aristotle and his successors as an attempt at science, not grand philosophy. You can explain things with an end/efficient/material/formal cause distinction. And so Aristotle and crew explained their world by positing that they had natures which included an end, and which had necessary properties referred to as "essences", and "accidental" properties which were fortuitous and unnecessary.

Anyway, much of the ... err... necessity for these categoricals is gone from science. We can have things develop from egg to adult without "ends". In effect we explain this mostly in what Aristotle would call "material" (the properties of the matter from which things are made) and "efficient" (the actual motive forces) causes. Ends are not required in the paradigmatic cases of living things.

Aquinas continued, presenting the locus classicus of the Argument from Design:
Now, whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God.
Once we lose the need for an ends-metaphysics, a teleology or entelechy (that is, a general external view of ends being imposed, or a specific view of ends being innate, respectively), we lose the force of this argument, but it is a pretty good attempt at the time to explain all the physical and in particular biological phenomena we see around us. [Incidentally, Aristotle restricted ends to living things; his successors were not so spare.]

But we no longer need it. We no longer need it in the matter of development, which is explained now as the outworking of the physical properties of the constituent elements of living organisms in a given environment (internal and external always need to be included here - chicken eggs don't develop well in space). And we no longer need it in the matter of how organisms came to be as they are - natural selection and the rest of evolutionary theory obviates that. So Aquinas quick and easy conclusion carries no formal force to us - there is an alternative.

But the modern intelligent design-theorists, the IDevotees, as I have called them, are not arguing to the existence of a designer, a point noted by that somewhat notorious philosopher Anthony Flew in his book Darwinism. Now they are arguing from a designer to an explanation of the properties of living things. Somehow, "design" is an explanation of why bacteria have flagella, why we have hemoglobin, and so on. So what is "design" that it explains anything?

This is something I'll follow up next time. Cheers

Tuesday, March 15, 2005

Family trees, genes, and races

Armand Marie Leroi, an evolutionary developmental biologist at Imperial College in London, writing in the New York Times has argued that races are not social constructs, but are biological realities.

This goes against the prevailing view of modern anthropology since Boaz in the early twentieth century, but the view that Leroi is engaging here is that of Richard Lewontin, the present doyen of evolutionary population biology.

The argument is that we do, indeed, find that biological traits, including, yes, skin colour, travel in groups so to speak. You can look at someone and find out that they are "African or European, but Ibo or Yoruba, perhaps even Celt or Castilian, or all of the above".

Lewontin had claimed in the 1970s that genes do not vary according to the standard racial groupings, but, says Leroi, his mistake was to not realise that they do vary in ensembles of genes, forming regional ethnic groups.

This is a kind of Family Resemblance Predicate analysis - and it is absolutely correct. But it fails to answer the real problems with racial analyses. Simply put, these biological realities are not races. They are regional variants, tribal forms, ethnic groups, whatever you like to call them, but they are not races.

The term "race" original just meant some family or tribe - this is the original sense of the Greek word "genos" from which we get "genus". But around 1800 or a bit before, it was fashion to define a small number of human races, in relation to European (and northern European at that) varieties. Even Kant had indulged in this, around 1775 in a lecture on Human Races. He wrote that we had to classify all living things, and in particular humans, in terms of their genealogical relationships. This is true enough. But given the paucity of data, and the tendency of light skinned people to identify everyone with dark skin as a single "kind" (with resonances derived from the biblical account of creation and the subsequent etiologies of different races), the taxonomy of races that came to be adopted was that of Blumenbach, as described in one of Gould's books. It was this that found its way into official American terminology.

And there lies the rub. "Race", once a perfectly useful term of biology, while at the same time a social term of discrimination and derogation, has political force. To a biologist, "race" means
... a Mendelian population, a reproductive community of individuals sharing a common gene pool. [John Buettner-Janusch, reviewing Carleton Coon in American Journal of Physical Anthropology, in 1966, vol 25:182-188. This is not a new debate, despite what Leroi implies.]
But there is no biological reality that answers to "Negro" or "Negroid" or "Asiatic" or "Amerindian" and so on. Sure, there are African populations. Some are clearly marked, like the Yorubi, Ibo, BaMabuti or San. But there is no "Black" race.

Leroi needs to recognise that when a scientist uses a word that has political cachet, it has political implications. In the symposium that issued forth in the 1968 book Science and the Concept of Race from which I drew the above quote, many scientists, including Dobzhansky, the great evolutionary biologist, and not coincidentally the mentor of Lewontin, attempted to claim that scientists had no social obligation qua scientists to use terms that impacted on the social struggle (remember, this is at the height of the Civil Rights era). But they must. Any use of "race" will issue forth in privileged social groups (some of them coinciding with biological geographical populations) claiming that their group is better than, or under threat from, some other social group (that may or may not coincide with a biological group).

There are no "races" among human beings. There are only biological geographical and ethnic variations, and socially constructed categories that instantiate the status quo.

Mead, M. Dobzhansky, Th., Tobach, E. and Light, R. E., eds, Science and the Concept of Race, New York: Columbia University Press, 1968