Re: Just So stories and science

["Matthew Bonnan" <mbonnan@hotmail.com>]

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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