Replies

My earlier comment:

"I'm not sure you understood his point. If that is NOT what is suggested, then HOW do you suggest that the base pair sequence necessary to sustain the simplest, and presumably first, chemical/biological life form originated?"

" I'm pretty sure I understand his point perfectly. What I am saying is that no competent student of evolution would suggest that the genome for any organism arose in one step. No organism in the sense we know them today ever just popped forth, sui generis, fully formed and ready to roll. Nobody really believes that ever happened. So to "demonstrate" the unlikeliness of that phenomenon is spectacularly useless - you're arguing against something that nobody really believes."

Ummm, where to start? I'm a physicist and not a biologist, so I will admit some ignorance. But as I understand it, the accepted view is that some organism, probably single celled, had to appear first. The authors' point was that even the simplest possible organism would still have an enormously complex genetic structure. His question is: "where does that precise b.p. sequence come from?" [if its' appearance predates natural selection]. This is what I meant by this preceeded natural selection: natural selection, by definition, requires at least two crucial ingredients; selection pressures and containers of genetic information (organisms). Prior to the existence of organims, there was no 'favored' or 'disfavored' selection. As a corollary, and perhaps as a motivation for defining the term 'organism', it seems to me that, at minimum, some form of reproduction/duplication must exist in order for natural selection to occur, by definition. (but not necessarily for 'selection pressures' to exist). Without an organism, discussions of the ability of natural selection to foment biological change over time is a mute point.

So, I find it amazing that you would write that:

"There is no "prior to the appearance of natural selection". There is no such time

Of course there is. Indeed, there is some 10 billion years of physical existence before organisms appeared. This is his whole point. Before organisms existed, what created the specific genetic sequence necessary to sustain that first organism? Pursuant to the original quote to which you referred, the context of the authors' discussion was of the probability of just such a thing occuring; i.e. the probability of a b.p. sequence occuring 'randomly' of sufficient complexity to sustain an n = 1, primitive single celled organism. In other words, he was referring to the very first 'structure' that can be defined as biological. As O'Reilly would say, "where am I wrong here"?

"As an analogy, does anyone really need a scientific study, complete with statistical analyses and geographical surveys and mathematical analyses of the physics involved, just to "demonstrate" how unlikely it is that Santa Claus exists? Of course not. What would be the point, since nobody seriously believes in Santa anyway?"

I'm not sure this statement and the context herein commute, so I'll leave this alone...

" I really don't think you can posit an environment where there is no such thing as a trait that is adaptive, or a trait that is dysfunctional. But if you can think of one, I'm interested to hear it. "

As expounded upon above, yes, I can posit such an environment. Indeed, there are too many to here enumerate, but they exist throughout the universe and across time, including the present. To wit, your claim is fallaciously predicated on the assumption that organisms exist in said environment.

But as I understand it, the accepted view is that some organism, probably single celled, had to appear first. The authors' point was that even the simplest possible organism would still have an enormously complex genetic structure.

That is not the accepted view, I think. It is entirely possibly for self-replicating compounds to exist that bear no resemblance whatsoever to single-celled organisms as we know them today. Simply acknowledging that possibility renders this article moot. Fine - we're not expected to believe that lightning flashed and a human crawled forth from the slime, instead we are supposed to believe that lightning flashed and a single-celled organism such as an amoeba crawled forth.

You are looking at the complexity of single-celled organisms as they exist now and assuming that the first self-replicating "creatures" were at least as complex - bearing analogous structures and such. That is not a requirement for evolutionary processes to occur. Other posters have discussed self-organizing systems - some of those posts might interest you.

In any case, this is all about abiogenesis, in the end, not evolution per se. Am I to assume that you have no objection then to evolution or natural selection, and that in fact your issues involve only abiogenesis?

Of course there is. Indeed, there is some 10 billion years of physical existence before organisms appeared. This is his whole point. Before organisms existed, what created the specific genetic sequence necessary to sustain that first organism?

Oh, I see. No, you misunderstand me. Natural selection is an effect of organisms living in an environment, any environment. To discuss natural selection in any other context is to abstract the effect away from the cause - it would be akin to discussing gravity with respect to a universe that had no physical bodies. Therefore, implicit in my discussion of natural selection is the assumption that there is an a environment, and an organism or organisms. "Before natural selection" would mean, I suppose, that you are really interested in a discussion of abiogenesis. As I said, others can discuss that probably better than I can. Just be aware that there is no requirement that the first self-replicating systems bear any resemblance whatsoever to contemporary organisms, and that there is a such thing as a self-organizing system.