22 August 2005

But why should we save the Wiliwili?

One of the comments that was inspired by my earlier post on the invasive gall wasps that are threatening some native Hawaiian plants raised a point that is worth responding to in detail, since it comes up fairly often both in arguments with anti-evolutionists and in discussions about the costs and benefits associated with conservation efforts:

"Big Bill" said:
"And further, letting foreign people plants and animals in always increases diversity. Sure, some native peoples, plants, and animals will die out, but it’s not like they have any right to the land. There is no God-given title. If the native peoples, plants and animals cannot compete and survive, that is their fault. It’s Darwin in action."

Bill's statement does capture a basic fact about the biological effects of invasive species: if the invasive species outcompetes the natives, resulting in the extinction of the native species, it is simply a case of natural selection. I cannot argue with that. There are some who might claim that situations involving invasives do not count, because the invasive arrived as the result of human intervention rather than "naturally". I dislike that argument, both because it ignores the fact that the effects would probably have been the same regardless of the mode of arrival and because it implies that humans aren't really part of nature.

In this case, there isn't any direct competition involved - the gall wasps aren't eating the food of some other species of insect. In fact, they aren't even eating the wiliwili trees to death. They are depositing their larvae inside the leaves. This damages the leaves that are used in this way, and the wasps are currently so successful at reproducing that they are damaging trees beyond repair. But no matter - the gall wasps are a new factor in the wiliwili's environment, and the wiliwili do not seem to be adapting quickly enough to adjust to this new environment. The same general pattern of events has probably occurred with different sets of species countless times over the last few billion years, and such events have likely been a contributing factor in the extinction of many, many species. The loss of the wiliwili would hardly be a unique or even uncommon occurance in the history of life. I wouldn't call it "Darwin in action", as the old man isn't known to have moved much since they stuck him under that old church floor, but the loss of the wiliwili would (will, if nothing changes) be the product of the harsh reality of natural selection.

How do I, as a person who accepts the obvious reality of evolution, justify taking action to preserve the wiliwili - or any other species - when it is failing the test of natural selection? For that matter, how does anyone who understands and accepts evolution justify aiding organisms that do not seem to be fit to survive without our help? Why is there such a field as conservation biology, particularly if it is filled with "Darwinist" scientists?

The answer is simple, it is clear, it is obvious to anyone who understands science, and it is apparently incomprehensible to any number of creationists. Science can provide us with information about the world that we can use to inform moral judgements, but it does not provide moral guidance. Scientific knowledge can tell us what the situation was, what it is now, and what it may or may not be in the future. It does not tell us what we should or should not do.
The question of whether or not we should try to preserve species requires us to make a moral judgement. There may be some people who think that a world that is populated by far fewer species than we see today might be a good place to live. I am not one of them, and I don't know anyone who is. Like many other people, when I look at nature I see something that is wonderful, even awesome - and I mean that in a very literal way: nature often evokes awe and wonder. I believe that a world in which entire communities of diverse species have been destroyed would be a far poorer place to live. I believe that we have a duty to pass on to our children a world that is better than the one we inherited, and I believe that doing our best to preserve the diversity of nature is part of doing that.

My understanding of science allows me to understant that the actions of the gall wasps are likely to lead to the extinction of the wiliwili unless something is done. My moral principles tell me that something should be done. My understanding of science does not change my moral principles, and my moral principles do not change my understanding or acceptance of science. And that is as it should be.

14 Comments:

Blogger Nic George said...

Well put. Is biodiversity important? I think the answer is YES regardless of how utilitarian you are. Humans need living world to survive! It might not hurt us if a few tropical trees go extinct – but how can we be sure? Do we know enough to say they are not key stone species the loss of which could cause other species in the Hawaiian Islands to become extinct. We have plenty of historical examples that show if societies wreck the natural environment they either collapse or end up with seriously reduced standards of living - Polynesian Islands, original civilizations from Fertile Crescent, Mayans, American Indian, the US dust bowl…, (Western civilization following the depletion of fossil fuels and phosphorous reserves?).

2:39 PM  
Anonymous tgibbs said...

There is a tendency, even among those who accept evolution, to simply substitute Natural Selection for God. But as you point out, natural selection is not like the Christian God, whose works are good by definition. If Natural Selection were a god, it would be more like the capricious pagan gods.

Although natural selection has given rise to us (which most of us regard as good) and much in nature that is beneficial or esthetically pleasing to us, there is nothing that guarantees that the outcome of natural selection will always be good, or consistent with our concepts of justice or morality.

So it is not a sin to interfere with natural selection--rather the advantages and disadvantages need to be considered on a case by case basis. While one might imagine that one could not improve upon the works of God, this is not true for natural selection, which by its vary nature tends to get stuck in local optima, not necessarily finding the global best solution to a design problem.

2:45 PM  
Blogger Linkmeister said...

I've got a more practical reason to save this tree: I have two, which flank my driveway on either side and provide a great deal of shade. I grant you they're a very dirty tree, but I really don't want to have mine die.

4:04 PM  
Anonymous Anonymous said...

The question of whether or not we should try to preserve species requires us to make a moral judgement. There may be some people who think that a world that is populated by far fewer species than we see today might be a good place to live. I am not one of them, and I don't know anyone who is. Like many other people, when I look at nature I see something that is wonderful, even awesome - and I mean that in a very literal way: nature often evokes awe and wonder. I believe that a world in which entire communities of diverse species have been destroyed would be a far poorer place to live. I believe that we have a duty to pass on to our children a world that is better than the one we inherited, and I believe that doing our best to preserve the diversity of nature is part of doing that.

Mike, you explained the end result of your moral judgement, but not the reasoning by which you got there. Just because you "believe" that the world would be a poorer place if many species are wiped out is a sentiment, not an argument. It might be cool if we still had dinosaurs around, but the evidence seems to indicate that them dying off was necessary for us to arrive on the scene.

As you say, few people think it's a good idea to go around killing off as many species as possible - the problem is that it's always a result of competing interests, usually economic. How do you measure the importance of biodiversity? Are certain species more valuable than others? Is there a linear relationship between the cost and the number of endangered species, or is it exponential? How do you balance biodiversity concerns with economic ones?

4:11 PM  
Anonymous Anonymous said...

You should bottle that essay and send it to the NPR show This I Believe.
Paul Flocken
sfbrules@*nospam*cs.com

4:16 PM  
Anonymous Jaime Headden said...

It was by our actions and stupidity that species were introduced in an environment. Thus any destruction, "right" or "wrong," is our fault. The loss of diversity becomes our responsibility as a part of this environment. The same was true of killing Native Americans with smallpox, and this will be true with any other introduced organisms where our lack of foresight impairs the world diversity. This is, in a nutshell, a moral obligation on our part to preserve diversity.

4:28 PM  
Anonymous Dave Harmon said...

Wonderful essay, well capturing the place of morality vis-a-vis science. I would, however, like to point out that a strong understanding of science does indeed encourage certain moral principles and biases.
The idea that "diversity is good" comes from our experience with ecosystems, especially the ones we've already trashed. So does our general dislike for "invader" species. Science also teaches us that (and why) destroying things is much easier than (re)creating them. Notably, it tells us that if we trash this planet, we get to live in the mess we made, until we fix it.

These are the sorts of moral judgements that science produces. It's not big on commandments, sin, or taboos, but there's a lot of stuff about consequences, and even some basic rules for responsibility.

tgibbs: "there is nothing that guarantees that the outcome of natural selection will always be good, or consistent with our concepts of justice or morality."

No guarantees, indeed - but maybe something short of that. Consider that at least some of our "gut feelings" about morality are based on instinct, and thus have been shaped by adaptation to the world we live in, especially including other humans. As Terry Pratchett wrote in The Last hero: "What goes around, comes around. If not examined too closely, it passes for justice."

5:29 PM  
Blogger Kele said...

Wouldn't another problem be that the environment (the animals, plants, bacteria, etc.) have been evolving together for a number of years and an invasive species throws this whole thing out of wack? Couldn't something like this screw up the entire environment?

6:38 PM  
Anonymous fred said...

I take a quite utilitarian stance on this point: if the introduction of new species forms a threat to humans (example, the meditteraenean sea algae), something should be done about it. But honestly, that is the only reason i see to intervene.
If a parasite were introduced by any other species, by natural means, and if it decimated the original population of that region, we would call it natural selection, as has happened many times before.
Other than our own survival, I don't see any moral obligation to save species from natural (allthough introduced) competitors or "enemies". (Except that it would be a pity, which is purely sentimental.)

11:52 PM  
Anonymous Shaggy Maniac said...

Whether or not to preserve biodiversity (however one defines it) really is determined by the outcome of interacting values. We may use scientific information to inform our values, but the decision to (re)intervene or not is based on values. Attempting to use an argument based on what is "only natural" (one way or the other) is an example of employing the naturalistic fallacy.

4:59 AM  
Anonymous spinner said...

Good post, though you didn't mention that practical scientific progress (and the consequent increase of human power and potential) is partly dependent on the preservation of nature in its myriad forms (as an inspiration for chemicals, medicines, structures, and systems). Who knows what purpose the Wiliwili may eventually serve? (Of course, this doesn't imply that the Wiliwili must be preserved at all cost - as other commenters have mentioned, there is a cost-benefit analysis to be performed.)

12:57 AM  
Anonymous Anonymous said...

Fred:

i Other than our own survival, I don't see any moral obligation to save species from natural (allthough introduced) competitors or "enemies". (Except that it would be a pity, which is purely sentimental.)

When you say 'our own survival' do you mean species survival? If so, you're drawing a line there between grounds for moral obligation and mere sentiment which I'm not sure stands up. Maybe it does - I'll admit 15 lines is not going to be a full declaration of your moral position - but couldn't that reasoning be used to turn a blind eye to any action or event which does not threaten our own survival? For the sake of argument, famine or war does not threaten species survival; nor does murder, for example. Indeed, it would take pretty extreme catastrophe to threaten our survival as a species! (I'll take it as read that tribal survival is written into that as well.)

I imagine it's unlikely that you would seriously advance the same argument for, say, letting nature take it's course in Niger; but what's the difference, logically speaking? Surely to act out of pity for the sufferings of others of our own species is also 'sentiment'?

I'm not implying parity between our own species and others; I am wondering if your utilitarian morality is consistent.

'Tis not contrary to reason to prefer the destruction of the whole world to the scratching of my finger.'

- Hume

4:23 AM  
Blogger jockoknox said...

The dominant invasive species on this planet is HOMO SAPIENS him/herself. I watch whole ecosystems being destroyed every day to be replaced either with concrete and pavement or sterile one dimensional deserts such as lawns,crop fields or orchards. I do not question the need for such, but I do observe that mankind's projects are becoming more and more massive and also more and more one dimensional. Natural diversity is actually disappearing in some localities in a very big way.

11:26 PM  
Anonymous Anonymous said...

Excellent point that choosing biodiversity can be a moral decision, and can not be a scientific one, but it doesn't have to be moral - some people prefer biodiversity for aesthetic (or possibly) reasons, with no moral basis at all.

4:18 PM  

Post a Comment

<< Home