Natural history
Feb 24th 2006Wallabynerd alert
This grew out of a discussion at The Art of Teaching Science. My reply was getting to be rather long so I moved it here instead. This’ll make rather more sense in the context of that post, at a very interesting site for anyone interested in how science is (and should be) taught.
As far as guessing, I don’t agree that is what scientists are doing. A theory is a long way from a guess. A theory is an explanation of factual information and observation.
Jack is right, “guess” is not quite the right word. My point is that “the theory of (macro) evolution” is an attempt to reconstruct a complex process that cannot be repeated on an experimental timescale. (So is “the theory of intelligent design”.)
I can go into the lab and collect facts about a reaction; I can develop a hypothesis that explains the facts I observe. I can test that hypothesis by changing the experimental conditions and seeing whether the hypothesis still explains the outcome. I can support my fledgling theory by testing it repeatedly.
A biologist cannot do quite the same thing with data about the colors of a butterfly’s wings, or even gene sequences. He can, at best, analyze some particular trait and conclude that two species are more closely related to each other than to a third species, and therefore may have diverged from that third species at an earlier date than they diverged from each other. This is not the same as watching the three species as they evolve.
A biologist willing to consider intelligent design also has this problem. A particular structure may show characteristics of design; it may be complex enough that the odds against its accidental evolution are astronomical. This is not the same as watching it emerge fully assembled from the head of Zeus.
In that respect, biology seems to have more in common with the study of history than that of “experimental” science. A historian can collect a mountain of evidence favoring her theory of the causes of the English Civil War, but there’s no way to test that theory by trying to recreate that particular war. She could generalize her theory by including studies of other civil wars. If she cared more for her theory than for the consequences, she could even test her theory by attempting to cause a civil war by applying (testing) the theory. In that sense, history is very scientific.
I should note that I’m distinguishing between studying an organism/tissue/cell/gene to learn more about how it currently lives/works, and studying it with a view to discovering where it came from. Observing finches and concluding that beak shape is related to diet is “experimental biology”; concluding that finches with beaks of similar shapes must be closely related is (natural) “history”.
In both cases — evolution and design — there can certainly be a big enough mountain of evidence to provide support for all but the most hard-headed critic to agree that the theory is correct.
3 Responses to “Natural history”
Jack Hassard on 24 Feb 2006 at 8:23 pm #
For many years I directed doctoral students studies in science education. When I first started (many years ago—let’s leave it at that), the majority of studies in the field of science education were quantitative studies—and these studies used pre-post test design models (often with multiple groups). The researcher was outside the system being studied, and used methods that involved testing, and quantitative observations. Emerging at the same time were studies that were labeled “qualitative studies,” and these studies, which grew out of anthropology (and to use your example ‘natural history), showed the researcher to be part of the system being investigated, and used a vast array of qualitative methods (journals, photography, video taping, artifact collections, and so forth. These studies now represent the majority of studies done in science education (and many other fields, as well). So, as I thought about your comment, the studies you described in biology focusing on evolution and I.D., would tend to fit the qualitative paradigm.
The problem that I.D. proponents have doesn’t dissapear, however, in a qualitative model. The I.D. approach uses examples which end up not being able to be explained, or in the I.D. model, if it is too difficult for science to explain, than we should “throw in the towel” and appeal to an intelligent design explanation. A qualitative approach to answering questions actually leads to much more “data” than what you would find being reported in studies that are quantitative.
What do you think?
Wallaby on 08 Mar 2006 at 9:53 am #
Long delay in my reply, it must be stellar, right? Actually I’ve been out of town.
Interesting comparison, I hadn’t thought of it in those terms. I think that you’re quite right about the distinction between the two types of “evidence”. (Having taken a couple courses myself in science education, I’m not willing to argue that the qualitative “personal experience” type is invalid.) I don’t think that’s the only line that can be drawn here.
There *is* quantitative evidence: the apparent age of rocks in which fossils were found, the distance between certain gene sequences, etc. The sequencing of a gene is a very experimental piece of work — any number of people can do it any number of times and reach the same answer.
The qualitative or historical aspect is when scientists take the quantitative evidence and then weave around it a story of where it came from. (It’s like trying to reconstruct a novel from the last page and scattered sentences from the rest.) This story — this hypothesis, if we’re treating it as experimental — cannot ever be repeated, in the same way that the English Civil War cannot be repeated.
It’s easy to see this “story” in any book by Dawkins, for instance: there’s a nice narrative describing how the first living cell developed and everything else since. Are these “data”? No, at best it’s “hypothesis” — a way to explain the observed facts.
Comparing this to the personal narrative overlooks the fact that the personal narrative is valid not because it’s personal or because it’s a narrative, but because the observer was really there. Making up the same kind of story when one’s really stayed at home is not research; it’s not science; it’s academic fraud.
Last time I checked, Dawkins was not millions of years old. “Climbing Mount Improbable” is a “Just-So Story” after the genes for rhino skin have been sequenced.
Wallaby on 08 Mar 2006 at 9:56 am #
Oh yeah –
As far as ID goes — you’re quite right, it uses example which the evolutionary approach is not able to explain. Evolution argues that intermediates exist(ed), each of which is sufficiently similar to its immediate neighbors to have a high probability of conversion to the next form and each of which is also independently functional in its
current form. ID argues that systems of “specified complexity” cannot have such intermediates — *not* just that we haven’t seen them yet.
Evolution urges scientists to “throw in the towel” and conclude that a billion years and oceans of primordial ooze are enough to allow practically anything to happen, even if we can’t see it happening now. ID says “if it walks like a duck, and quacks like a duck, and looks like a duck, we should recognize that it might be a duck — whether we personally like ducks or not.”
There’s a very nice intro to ID that actually treats this very argument (and many more), good place to start for learning what ID actually claims (better than, say, Panda’s Thumb, cough cough). It’s at http://www.ideacenter.org/resources/faq.php.