5/16/2007

What exactly is natural selection?

I am no scientist--my background in the sciences is, at best, patchy--but I try to learn what I can about the natural sciences. I can't help myself from voraciously consuming news of the latest breakthroughs (for instance, check this out), or from spending hours on Wikipedia reading articles on quantum mechanics that I can scarcely comprehend, or from dabbling in a little philosophy of science now and then.

One issue that has long fascinated me is evolution. A few years ago, I read Dawkins' The Blind Watchmaker and was impressed by the way he connected evolution to other physical phenomena. If we think about things in terms of the probability that they should exist--this is highly speculative but bear with me--we would expect to find, for instance, things that last a long time (like rocks) or that are frequently produced (like clouds). But add in something that can replicate itself--but does so imperfectly--and the history of life on this planet seems like a foregone conclusion. (This is a partial response to creationist "arguments" concerning the improbability of life.)

I've also had debates with colleagues about evolution, trying to argue on premises like Dawkins' that natural selection (leaving aside the phenomena of mutation/variation and genetic drift, which are in some ways more straightforward, as generators of a kind of "randomness") is a general physical process not specific to biological organisms. Even higher-level phenomena like culture and technology, I would say, undergo an analogous process in their development.

As it turns out there are physicists who are trying to argue exactly this. A common "criticism" leveled by creationist idiots is that life is incompatible with the second law of thermal dynamics (viz., that entropy in a closed system increases over time). Contrary to what we might think, living things actually do more to increase entropy than do non-living things. One physicist in particular, Roderick Dewar, has even argued that what natural selection is really selecting for is not something vague like "fitness" but rather "maximum entropy production" (MEP):

Dewar has shown that MEP is the most probable behavior of an open, nonequilibrium system made up of many interacting elements, provided that system is free to “choose” its state and not subject to any strong external forces.... The large-scale state of MEP represents the largest proportion of the countless possible arrangements of the system's microscopic parts, regardless of what those parts are up to.

Natural selection in biology could work the same way, Dewar thinks: “In physics, to speak of natural selection is to ask, among all possible states, which is the one that nature selects.” This, he points out, is a question of probability. “The state that nature selects is the one that can be realized in more ways than any other. Biologists don't think like that, but I want to entertain the hypothesis that natural selection in biology works the same way, and see where that gets us.”


The issues here are actually quite complex, and I encourage you to read the whole article, which includes opposing points of view and an alternative theory about increasing matter and energy "flow"--did someone say "Heraclitus"?

Part of what we're dealing with is a question about the distinction between living and non-living things, but it also pertains to the issue of scientific reductionism: is biology ultimately explicable in terms of physics? Personally, I'm inclined to believe in emergent properties that require "higher" levels of description to account for.

In any case, I think it advantageous to see natural selection as a more general--dare I say metaphysical?--principle. Some have even argued that a kind of selection operates between different universes--although this is too speculative to entertain as anything more than a neat idea. When it comes down to it, we may not be able to ask why there is something rather than nothing, but the question of why this something rather than another may be in bounds.

5/03/2007

Emotions and Reason: Together at Last

The emotion-reason connection has now bled through to popular media, as evidenced in this Boston Globe article:

Ever since Plato, scholars have drawn a clear distinction between thinking and feeling. Cognitive psychology tended to reinforce this divide: emotions were seen as interfering with cognition; they were the antagonists of reason. Now, building on more than a decade of mounting work, researchers have discovered that it is impossible to understand how we think without understanding how we feel.

[...]

Antonio Damasio, a neuroscientist at USC, has played a pivotal role in challenging the old assumptions and establishing emotions as an important scientific subject. When Damasio first published his results in the early 1990s, most cognitive scientists assumed that emotions interfered with rational thought. A person without any emotions should be a better thinker, since their cortical computer could process information without any distractions.

But Damasio sought out patients who had suffered brain injuries that prevented them from perceiving their own feelings, and put this idea to the test. The lives of these patients quickly fell apart, he found, because they could not make effective decisions. Some made terrible investments and ended up bankrupt; most just spent hours deliberating over irrelevant details, such as where to eat lunch. These results suggest that proper thinking requires feeling. Pure reason is a disease.


Besides Damasio (whose Looking for Spinoza is a must read!), the article makes reference to other theorists who I've been in the habit of reading, Jon Haidt and Josh Greene.

Spinoza, of course, goes unmentioned, but again we find that he was centuries ahead of his time.

(Tangential Remarks: Recently, I've been toying with some unusual interpretations of Spinoza, not so far from Damasio's neuroscience-infused account of the mind-body relationship. For instance, the many-worlds interpretation of quantum mechanics would be consistent with Spinoza's claim that everything that is possible exists.

Now I'm not so brash as to claim that Spinoza anticipated modern physics, anymore than he anticipated evolution with his outstanding refutation of intelligent design in Ethics I Appendix. Rather, like Damasio has argued with respect to the brain, Spinoza provides a framework for thinking about the sciences that is far preferable to other paradigms, like the Cartesian.

In a similar vein, Spinoza also seems to have a notion of identity as continuing proportion which meshes nicely with current ideas about identity as patterns of information--which has now led me to believe that mind uploading is possible [particularly if the upload is gradual, but perhaps even in the case of instantaneous transfer or the activation of a "backup" copy--imagine being able to "save" your life story!--it's something I've wanted to do for as long as I've been playing RPGs].

These recent ideas, which are extremely exciting, have spawned from my recent reading of Hans Moravec's brilliant 1988 work Mind Children. Moravec's solution to the problem of consciousness copying strikes me as brilliant, if extremely counterintuitive.

I hope to write more on this work at some other point, because it's been extremely fruitful for my thinking: so much so, that I think the more appropriate title would be Mind Fuck [which would be a natural predecessor to Mind Children, anyway.] The first 100 pages can be a bit boring, especially since he dabbles in what's state of the art for 1988 [i.e., even before the Internet], but beginning with the fourth chapter's discussion of the Robotic Bush [not the George variety, but the branching kind] things take a turn for the surreal-yet-plausible.)