December 15, 2004


Over the weekend, I came across the oddest passage in the book I've been reading on trilobites, one that partially answers, for me at least, a question I hinted at in connection with the conversion of longtime atheist Anthony Flew to deism (Aziz, by the way, has much more information on Flew). Which is, do we fault evolutionists or evolutionary science for the still-controversial nature of Darwin's theory.

Getting back to the trilobites -- in the book, Richard Fortey writes on page 182,

Without death there is little innovation. Extinction -- death of a species -- is part and parcel of evolutionary change. In the absence of this kind of extinction new developments would not prosper. In our own history, periods when ideas have been perpetuated by dogma, preventing replacement of old by new ideas, have also been times of stultifying stagnation. The Dark Ages in western society were the most static, least innovative of times. So the fact that trilobites were replaced by batches of successive species through their long history was a testimony to their evolutionary vigor.

The passage is endlessly bizarre -- but let's take it apart. First, we hear about extinction being a good thing. Then why do so many scientists argue for conservation of natural habitat, for heroic efforts to preserve endangered species? Aren't we then impeding new developments? A few pages on (page 185, to be exact), Fortey writes that human beings are "now causing another extinction as severe as that endured by the trilobites at the end of the Ordovician..." (ellipsis in original), and wonders whether we will have the wisdom to change our behavior. But why should we -- isn't our irrational attachment to whales, tigers and so on more or less analogous to the our attachment to stultifying dogma?

Speaking of which -- Fortey's equation of lack of extinction with the stultifying effect of old ideas not being driven out by new ideas is also weird. A stultifying, stable dogma might be, evolutionarily speaking, more advantageous than a shifting, innovative one. After all, it wasn't Medieval man who was on the verge of causing a catastrophic mass extinction (which, if the most pessimistic of some of the environmental doomsayers are correct, may well include the human species); it's modern man, with all our doodads and gadgets and geegaws. If Fortey's analogy holds, he should be demanding we forgo all the devil's devices and, Amish-like, return to a pastoral lifestyle in tiny self-sufficient, non-gas-guzzling communities. (The Amish, in fact, may be too modern.)

I could go on -- the Dark Ages were dark in part because the catastrophic collapse of Roman institutions -- of the classical world -- created a condition of anarchy -- a situation that surely was not the fault of those born during the Dark Ages. One of the things that restored, if not the political order of Rome, at least some sense of shared identity and cultural order, was Latin Christianity. Its monasteries did their best to preserve the fragments of classical learning in their possession. The vast majority of the population -- perhaps 90 to 95 percent -- were engaged in the tedious business of growing enough food to support the rest of the population. In such a context, what sorts of new ideas does Fortey think were being suppressed?

I would go on to point out the number of dark age innovations -- the heavy plow, the stirrup, and so on, but there's not much point. Suffice it to say that Fortey chooses an unfortunate metaphor, and in doing so betrays a bit of prejudice, a fair amount of ignorance, and a suggestion that he doesn't really think things through. And he's one of the more engaging populizers of evolution ...

Posted by Ideofact at December 15, 2004 12:09 AM

I think you're missing a valid distinction in types of extinction. Historical extinctions occuring through events such as sudden climate change or disease opened up new ecological niches which new species could expand into.

Man-made extinctions don't, in most cases. Where extinctions come about because of habitat destruction or dumping massive amounts of pollution into the habitat, ecological niches are destroyed instead of being recycled.

Another very common cause of manmade extinction is the expansion of species into new environments. This is especially common on islands, where species that evolve to fit the particular closed ecosystem in place get overwhelmed when human-introduced species and activities drastically change the ecosystem. Again, there are no real new niches created or, if there are, they are niches for animals like rats, dogs, and pigs which follow human activity and are hardly scarce to begin with.

The effect in each case isn't merely change from one species to another, but a net loss in biological diversity.

Posted by: Alex at December 19, 2004 04:48 AM


I'm not sure that the distinction you're making is one that can be made, because you have to infer tha mankind is unnatural, whereas I'm assuming that anything mankind does is as natural as, say, an extraterrestrial event like a meteor landing off the Yucatan penninsula and causing a massive extinction.

Human activity is pumping a great deal of carbon into the atmosphere through the burning of fossile fuels -- I seem to recall from my geology class that the earth's atmosphere contained far more carbon in the precambrian and cambrian periods than it does now.

I suppose you could argue that humans have choices about these things, although I'm not sure that we do in any real sense. Yes, you can forgo a bag of potato chips because you'll be sitting down to a steak dinner in an hour, but I doubt that, absent the sort of coercive force associated with totalitarian regimes, you could convince people to starve themselves for their own good -- or go cold or forgo fresh fruit in the winter or deny themselves any of the other benefits that our energy economy make affordable.

I have no problem with preserving habitats or species, and I'm happy to do it, but I also concede that it's a choice I'm making on the basis of a rather stultifying dogma, one which puts rather a low value on human happiness and progress.

Posted by: Bill at December 21, 2004 05:50 PM