Posted on 04/14/2002 12:31:25 AM PDT by sourcery
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The point, however, is laws--laws of fitness which allow testable a priori predictions, not a posteriori explanations. Natural selection as actually used can be used to explain both mortality (of say humans) and immortality unless slain (of sponges), prolific reproduction (of cockroaches) and small numbers of offspring (of humans or certain predators), etc.
In a previous exchange on the subject, jennyp offered as a possible falsification of Darwinian theory an observation of an increasing incidence of a trait which in its homozygous form killed the organism before it could reproduce, but bestowed no survival advantage in its heterozygous form. I replied that it would be certain that the response to such an observation would be to postulate an as-yet-unknown and ill-understood survival advantage associated with the heterozygous form of the trait.
While Darwinism holds out in possible outline form a sketch of what a scientific theory of biological diversity might look like, in practice so long as the outline is not filled in, and natural selection continues to be used as a tautology, it isn't science. (I again remind you I am a Popperian.) Particular, falsifiable theories of natural selection in particular settings are good science. Darwinism as used polemically as an argument-from-no-design is not.
Right on, TRD!
Well, American blacks have sickle cell anemia even though malaria does not occur in the USA. If we didn't know history, you would assume that this falsified evolution. This neglects the difference between the short, medium, and long term ability of natural selection to change populations.
and natural selection continues to be used as a tautology. Particular, falsifiable theories of natural selection in particular settings are good science. Darwinism as used polemically as an argument-from-no-design is not.
I need a concrete example there, rather than just the thesis.
I don't remember stating that, but it does sound like it'd be a valid falsification.
If that happened, I'd offer the unknown survival advantage hypothesis too. Sure, it could be the anomaly that brings down the Darwinian edifice, but without further facts, it's much better to bet on natural selection.
I think where falsifiability comes in is in the next step: when scientists try to find this hypothetical survival advantage. If they find it, then NS survived the falsification attempt. If they don't find it, then either they weren't looking in the right places or a hole has been found in NS. (I won't say NS would be completely falsified, since it is validated so often it's pretty strong in general!)
(Trying to be precise here, 'cuz I've never put this into words before:) Falsification often is not a cut & dried phenomenon, since the "non-falsification of the gaps" is always there as a theoretical possibility. And of course in the real world, theories get dinged all the time by confirmed anomalies. The question is how do you tell that a theory is dinged beyond repair.
Have you heard of Imre Lakatos? (I just heard about him a minute ago. :-) He seems to have refined Kuhn's theories of duelling paradigms.
Lakatos drew a distinction between refutation (evidence that counts against a theory) and rejection (deciding that the original theory has to be replaced by a new theory). He also argued that it's not individual theories that are accepted/rejected/refuted, but something more complex which he called a "research program". Any research program contains different elements. In particular he defined two terms: the positive and negative heuristic. The positive heuristic was that part of the program which directed scientists toward fruitful avenues of enquiry. The negative heuristic directed them away from other issues and questions. He also argued that the core propositions of any research program were insulated from being falsified by a "protective belt" of auxiliary hypotheses. That's why research programs could resist the occasional negative result. A successful research program build up more and more of these, protecting the core ever more effectively. However, lots of important negative results eat away at this belt, eventually casting doubt on the core propositions.
Interesting way of looking at it. It explains why "naïve falsificationism" can't explain the survival of Newtonian physics, for example. Or Darwinism, for that matter, IMO.
Yes
What do you think about Occum's Razor?
I've never heard of immortal sponges. Using natural selection, I'd expect to discover that those sponges can have offspring all their lives, since the prediction as illustrated in post 125 is that deleterious mutations can only flourish in a species' gene pool after the childbearing years are over.
Junior, do you know the explanation for these immortal sponges?
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Woo hoo! Natural selection survives falsification again!
Seriously, if that wasn't the case, it would be very surprising given what we know about NS.
On a related note, I remember hearing a longevity researcher saying that the way to extend human life is to trick the body into thinking it's still in its childbearing years, thus preventing the "faulty" genes from kicking in. Maybe that's why estrogen is the fountain of youth for women. (It REALLY improves the quality of life in our postmenopausal years.)
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n the last decade or so, creationism has grown sophisticated. Oh, the old-fashioned creationists are still around, especially in the Bible Belt. They're the ones who believe that the earth is only a few thousand years old, that God created it and all its inhabitants in six days and that fossils are a product of Noah's flood. In the early 1990's, however, a new breed of creationists appeared. These ''neo-creos,'' as they have been called, are no Dogpatch hayseeds. They have Ph.D.'s and occupy positions at some of the better universities. The case they make against Darwinism does not rest on the authority of Scripture; rather, it proceeds from premises that are scientific and philosophical, invoking esoteric ideas in molecular biology, information theory and the logic of hypothesis testing. 