Comments by Jonatan

Comment #124137 by Jonatan on February 8, 2008 at 12:47 pm

Bitbutter, the role of natural selection in the process of how life got started is not as irrelevant as you may think. Its effect would start as soon as a self replicating molecule such as nucleic acid would appear.

Now, to imagine how nucleic acid could form under certain physical/chemical conditions is not particularly difficult. Hence, depending on your definition of life, natural selection could well have something to do in the appearance of e.g. the first proto-cellular machinery helping some nucleic acid molecules to replicate faster than their neighbors.

2. Are Darwin's Theories Fact or Faith Issues?

Comment #121506 by Jonatan on February 3, 2008 at 2:06 pm

Once again, the creationist/ID morons have tried to use the fact that sometimes the word 'theory' appears next to the word 'evolution' to imply that there is some kind of uncertainty about the existence of biological evolution as a phenomenon.

Unfortunately, PZ, in an otherwise great performance, failed in my opinion to clearly explain why this is nonsense. There is a profound epistemological confusion at the core of this issue it seems to me. So, being an evolutionary biologist myself, here's my modest suggestion of line of attack for future debaters (I've never taken part in such debate and I don't think I would ever do it).

First of all, evolution, defined as descent with modification, is a fact, in the same way that gravity is a fact. It happens all the time in laboratories around the world, and has been documented thousands of time in natural and domestic populations. No one can argue that there is no documented cases of a population for which the mean value of a trait has changed through time, and this is what evolution means. Biological organisms undoubtedly can change over time. So one cannot say that evolution does not exist. The exact same thing can be said of mechanisms such as natural selection, it is a fact (e.g. the entire vaccine industry is based on it). Even speciation, the evolution of reproductive isolation between populations, has been produced in the lab several times (e.g. in Drosophila fruit flies), plus of course all the evidence from natural populations.

That being said, because something is a factual phenomenon doesn't remove the necessity to explain it in details. So, as with gravitational theories (Newtonian or Einsteinian), we need an evolutionary theory: an explanatory framework to link causes and effects with forces (evolutionary forces such as natural selection, sexual selection, genetic drift, migration, etc...). Because there are theories of gravitation, should we say that gravity is only a theory ?

So to summarize, I think that in these kind of confrontations, this dichotomy between a factual phenomenon (e.g. biological evolution or gravity) and a theory to explain how it works, should be made clear. In my view, this dishonest tactic would be more easily exposed and dismissed by making this distinction, than by explaining the 'non-pejorative' connotation of the word theory in science, as it is often done by evolutionary biologists. Now, I know that ID people could come and say that they agree with evolution itself and that what they propose is just another theory to explain it, but at least, starting from there, one can easily ask them to explain what exactly is this theory and how it is better than the existing one, thereby shifting the burden of the proof back on the right shoulders...and watching them sink under its weight...