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Re: Just So stories and science



Brian "philidor11" said:

My concern, in addition, was what happens when a hypothesis is carefully
formulated and then means of testing it effectively are found, and the
hypothesis passes. You have proven the hypothesis plausible, and the tests
continue, as you say.
Though the hypothesis is plausible, speculate for a moment that you could
also develop a competing hypothesis which meets the available facts and
stands up to the best tests you can devise.
The fact that you have found two hypotheses that meet the available facts
and tests means that neither can be preferred at that point. How could you
choose?

I suppose one could defer to parsimony, for instance. If there are two competing hypotheses about, say, theropod evolution, one might choose the hypothesis that requires the least amount of "steps." From a functional standpoint, although two competing functional scenarios might appear to have equal evidence, the more simple of the two hypotheses here would probably be preferred pending further evidence.


I know the follow up question: but what if both hypotheses are completely equal in terms of evidence or we have an ambiguous result? I will open a potential can of worms here and say that something like this has happened in dinosaur paleontology, and it is the competing hypotheses for "cold-blooded" or "warm-blooded" dinosaurs. To my knowledge (and in my opinion, which, like anyone's, has bias), the evidence for or against "warm-blooded" dinosaurs is unfortunately in a stalemate. The evidence is relatively ambiguous. I am hoping new studies by Padian, Horner, and de Ricqles, as well as work by Kristina Curry, Farlow, and others will start to improve our understanding of this fascinating branch of dino biology, but for now the evidence for or against "warm-blooded" dinos is relatively ambiguous.

In this case, perhaps the best thing to do is keep throwing everything we have at it but to try and remain as neutral to the results as possible. In other words, sometimes in science we have to wait and be patient, and many times this is very difficult! =) As human beings we want to know why and want answers, and that's what makes parts of paleontology both exciting and frustrating.

Now, the second-hand quote from Gould and Lewontin is partly about the
possibility that someone devising a hypothesis might immediately look for an
adaptation explanation and ignore other possibilities; I'd add, even if the
adaptation explanation would prove no better than the alternative.

I'm sure it happens more often than anyone would like. The ideal goal would be to try and be as self-critical of yourself as possible. But as all good scientists realize, the easiest person to fool is yourself. That's where peer review comes in. You present your data and observations, explain what you think is going on, propose a testable hypothesis, and throw it to the wolves. If your data checks and your observations are repeatable, and others come to similar conclusions, perhaps your hypothesis has some merit. If not, chinks in the "armor" show up quickly.


So, for everyone on the list who may wonder, all the professional papers you see on dinosaurs in scientific journals have passed an initial round of peer review. Most papers are not accepted immediately and usually go through a round or two of revisions and criticisms from other paleontologists. Once published, others in and out of the field can read the paper, and check the logic and evidence on which the conclusions were based. The papers become part of the cumulative human knowledge about dinosaurs, and are open to be challenged and falsified by anyone.

By not looking for alternative hypotheses, you have strengthened
artificially your first idea.  It's a sort of test you have not performed.

Again, with luck this sort of thing would be caught in peer review. If not, and the paper is published, others probably will catch the error sooner or later.


The other piece concerns logic. I had a co-worker who would not just accept
an idea of mine, but would doggedly follow every step, including the logic.
He would make me think hard when he asked, 'Why isn't it just as logical to
think that...' or 'Why do you assume that...'. To draw a logical conclusion
is one thing, to find the necessity of your conclusion is something else.

Sure. I will just point out again that ultimately it boils down to evidence and data. Evidence eventually wins out, and helps us determine which hypothesis is likely more accurate. There are many possible dinosaur family trees and many possible dinosaur functional regimes, but the ones that will be accepted are ones which are testable using evidence and data. If that cannot be done, we are merely asserting a logical construct which we happen to like. Thus, we would no longer be doing paleontology.


Just as an alternate hypothesis can affect whether my hypothesis can be
accepted, so a single place in my logic where another conclusion is possible
from the premises I have established weakens the force of my argument.
If I share a bias toward a certain type explanation with everyone else I
have to persuade, then I'm going to have an easier time selling my
hypothesis.

Unfortunately, yes. However, it is the evidence that wins converts to a particular hypothesis or theory about dinosaurs. Take dinosaur extinction. The meteorite impact hypothesis was greeted with much skepticism and criticism and definitely some unfair scoffing. However, as evidence has mounted, more scientists have decided that the impact theory better explains the terminal K/T extinctions than other competing hypotheses based on evidence.


Even so, I have to look for alternatives exhaustively.  I'm
wondering whether the data in some parts of our favorite subject are
sufficient to be unsuccessful finding plausible alternative hypotheses or
logical conclusions.

Yes, but there does come a point with many theories where unless something truly remarkable is found that shakes their basis, we generally assume they are solid. For instance, the theory of evolution is implicit and assumed in all of dinosaur science because both the evidence that supports it and its explanatory power continue to enable predictions and testable hypotheses about dinosaurs and it provides a framework within which we can work. Evolution is still up for being falsified, but the amount of evidence and explanatory power necessary to do that would have to both account for everything evolution already does and explain more and better where evolution fails. At the moment, the theory is so strong that it has become the backbone of all of modern biology, including dinosaur paleontology.


Pinker & Bloom are arguing
here that in some specific cases, such as the eye, it is impossible to
consider other hypothetical solutions besides adaptation.  They go on to
list why alternatives are impossible.

Well, if the eye is viewed in its present complexity, then they may have a point. However, if detection of light waves arose through chance mutation of "eye spots," these novelities may have allowed organisms that had them to evade light or move toward it or whatever, but it would an "exaptation": something that proved useful but that wasn't planned. The eye, then, may have got it's start by chance and ended up benefitting organisms before becoming an integral part of survival.


I think I've said enough for today.  Enjoy all? =)

Matt Bonnan

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