Free Republic
Browse · Search
Bloggers & Personal
Topics · Post Article

To: Mr. Silverback
One can judge a theory's validity by the accuracy of predictions it makes. Can you identify a prediction evolutionary theory has made about biology that has been proven true by research? For guidance, consider the many predictions the theory of relativity made that have been proven dead on by spacecraft.

Also, can you identify a single drug, treatment or surgical procedure that has required evolutionary theory to be developed? If not, how could a theory be as fundamental to biological science as electromagnetism is to physical science and not affect the development of new medical frontiers?

Actually, yes. In my own research, I make plenty of predictions that are based on the principles of evolution. In fact, I cannot imagine trying to make predictions without the theoretical framework to support them. For example, during my graduate work, I was very interested in a particular toxic response pathway. This pathway exists in every vertebrate species tested.

Let's say that I want to examine another species to find the key proteins involved in this pathway. Under a creationist "theory," there would be a limited number of possibilities. Either the pathway would be identical in all species tested, or at least identical within the broad group (for instance, all mammals would have the same version, all reptiles would have the same version, etc.) Or else the pathway would be tailor made for each species, to make it more suitable for its habitat. Under the first assumption, looking for the proteins would be trivial--since they're identical, it would not take a very complicated research plan to find it. Under the second assumption, looking for the proteins would be a huge undertaking, because there wouldn't necessarily even be something similar to look for. But neither one of those situations is the case. Evolutionary theory tells me that the pathway will be highly similar in closely related species, and more divergent in distantly related species. So that is the assumption I will use to design my experimental approach. I will use as my template the proteins that have already been identified and sequenced in a closely related species, because I know that they will be different, but not so different that using materials from one species won't work when used in another species.

As far as drugs, treatments, and surgical procedures--they are all developed using animal models; without the theory of evolution informing us that we are biologically similar to these animals, and how much similarity there is, we wouldn't be able to, for example, research pig cardiology and apply the knowledge to human medicine. Under creationist "theory," we'd have to do the medical research in humans because we would have no reason to assume that any treatment developed for an animal would work in a human (in fact, we'd have to assume that no treatment developed in animals would be at all applicable to human medicine--according to Genesis, humans were created separately from animals and are therefore different).

Getting outside of my field of basic medical research, evolutionary theory has been beautifully validated by the new molecular techniques that have been developed in the last half century or so. Prior to molecular techniques, taxonomists spent inordinate amounts of time dissecting, measuring, and comparing animals to come up with evolutionary relationships between them. For instance, they would look at the lengths of bones relative to the size of the body, and make conclusions of relatedness based on how similar the bone measurements were between different species. There are many such observations they made, which they used to classify species as being more or less closely related, and to develop phylogenetic trees illustrating the relationships. According to evolutionary theory, these relationships should be present all the way down to the molecular level--for instance, a specific gene should be more similar between two species of duck than it is between a duck and a pigeon. And that has turned out to be the case in thousands of genes sequenced. The sequencing results, as it turns out, correspond very well to the relationships already determined through taxonomy.

152 posted on 08/21/2011 3:44:57 PM PDT by exDemMom (Now that I've finally accepted that I'm living a bad hair life, I'm more at peace with the world.)
[ Post Reply | Private Reply | To 150 | View Replies ]


To: exDemMom; Mr. Silverback
Evolutionary theory tells me that the pathway will be highly similar in closely related species, and more divergent in distantly related species.

You do see, don't you, that you're begging the question? I know that in my graduate level work in the biological sciences (neurobio/pharm/phys) the appeal to phylogenetic similarities is more of a genuflection than anything. Only in the Department of Evolution/Ecology is it of any real importance. Read through Alberts Molecular Biology of the Cell. Evolution is scarcely mentioned. Why? It's not necessary for understanding the molecular biology of the cell. Someone may want along the way to invent ad hoc stories to explain why this or that is like this or that or not like this or that or the other. Molecular biology has become a powerful field in science because of the techniques developed to investigate the workings of the cell. There is nothing about cellular metabolism or architecture that is inexplicable without an appeal to a theory of evolution. Most of what passes for an evolutionary explanation in most of actual experimental biology amounts to a form of parasitism by which a philosophical predisposition hitches a ride with successful experimental technique and then claims credit for its success.
153 posted on 08/21/2011 4:14:50 PM PDT by aruanan
[ Post Reply | Private Reply | To 152 | View Replies ]

Free Republic
Browse · Search
Bloggers & Personal
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson