Sunday, January 15, 2012

Chapter 5 Lennox Dissection

I am going to have fun here. In chapter 5, Lennox is brave and takes on, as a mathematician, the quantitative statistical corollaries of the Modern Evolutionary synthesis, as described by renowned Biologists such as Richard Dawkins, and finds them severely lacking in quantitative believability. I pretty much agree with him on every detail except the conclusion. Clearly, the biologists, have Occam Razored out plausible naturalistic explanations for the yawning gaps between what and how speciation happens as explained by the synthesis, and what is observed in both the geologic record(speciation is way more jumpy than the synthesis explains) and what is observed as a result of artificial selection(lack of speciation even after continued selective breeding). Lennox completes the obvious mistake of the biologists who decided on the synthesis and those who fail to overturn it, by Occam Razoring out even the mechanism that has the most scientific credibility and replacing it with the simplest explanation of all, a God designer. The plausible naturalistic explanations are not mentioned in Lennoxes book, and to be fair, they are not mentioned in the God Delusion either, except perhaps briefly as something to mock. The naturalistic explanations that would each close the yawning gap of macro evolution are as follows - horizontal gene transfer, Neo-Lamarckism ie. ways that the environment can have direct baring on how, when,and what type of mutations happen, group selection theories - more important with some gregarious species than others, design style programs programmed into the DNA or in the subconscious of brains, and selective breaching of the Weismann barrier. Some or all of these are postulated by some biologists some of the time, but the burden of proof is extremely onerous, and experiments are notoriously hard to design, and are expensive without much chance of "pay dirt", especially if biologist peers keep ruling them inconclusive even if the data lends to these alternative explanations. The statistical issues that Lennox brings up through reductionism are real, and the corollary should be for the biologists to shift the burden of proof to a requirement to prove that some of these other explanations are not happening during macro speciation.

6 comments:

Dr Clam said...

Hmm, hrm, I'm not so convinced that there is any need to dismiss natural selection acting on 'random' fluctuations just yet. I think Lennox is overstating the problems for ideological reasons and you are overstating them as a fellow member of the contrarian brotherhood. (Ave Eris, frater)

The *unquestionable* scientific evidence is the sequence of relics of life in time, and the genetic links between existing living things, which paint an obvious picture of relatedness and radiation from a common ancestor. Everything else we can argue about.

I think sexual selection naturally attracts species towards stasis and punctuated equilbrium is what we should *expect* from evolution driven by natural selection alone were relatively stable social and environmental conditions are occasionally punctuated by chaos.

Marco said...

There is unquestionable evidence of the sequence of relics of watches in time, and blueprint links between all known timepieces which paint a picture of relatedness and radiation from common ancestry. This says nothing about how relevant our selection (ie which watches we buy) is and the random nature of design changes to the basic watch design is. It doesn't matter how you toss the dice, random changes and selection on a sundial is never going to get you a watch. There is no quantitative believability about it. My perception is of biologists waving their hands saying, well, it happened, and none of the other theories is proven- this one is, so it must be plausible for it to be the whole explanation. It's not good enough. If you use reduction to simplify the mathematics, and it comes out as impossibly improbable even for a fruit fly, the least they could do is say that one of these other naturalistic theories must also be happening.

Dr Clam said...

It doesn't matter how you toss the dice, random changes and selection on a sundial is never going to get you a watch.

You have been awarded one bad analogy point: *biochemically*, we are all very, very, similar watches.

1) Can you re-do the maths? I would trust it more if you did it rather than Lennox. I don't trust it.

2) Evolution is constrained by history so we cannot generalise from our failure to obtain bizarre descendants from fruit flies or cats. *Most* species leave no descendants; maybe *most* species have no stretches of DNA that can mutate randomly enough to generate something viable. Doesn't invalidate natural selection and random mutation for an overall picture.

Marco said...

On 1) I will look closer again at the maths. My best bet would be to look at the rebuttals from mathematically minded biologists as a guide on who is doing the exaggerating. The last time we argued this point we didn't really get anywhere.

On 2) I am not prepared to take, on faith that micro evolution adds up to macro evolution without it being observable. After all, species jumps happen in short geologic time scales, which should be experimentally derivable. I am convinced that contrived experiments that put (say fruit flies) under a great deal of environmental stress in pseudo- natural conditions otherwise, would more plausibly eventually jump a species barrier. I think all species are capable of it, it is quite clear that fiddling artificially, even while searching for beneficial mutations, would doom the line rather than help it.

Dr Clam said...

You should write a book outlining the Marconomic approach to evolutionary biology and the origins of life. Most of the panspermia people out there are tangled up with 'intelligent design' or the 'steady-state universe' and the niche needs filling.

Marco said...

I still need to bounce ideas off you to discern between the plausible but unproven and the provably wrong or "If you say it like that it's provably wrong" etc. before I can even compose the ideas in words. I don't really want to own it - nobody in the general public of people interested in this stuff is going to even read what I have to say, let alone dismiss it out of hand before finishing it. Even with the Neo-lamarckism stuff, an "Hmm that is an interesting theory" from Klaus Rohde being a biologist meant more to the theory than a glowing review from someone random would be. The thing is, that
1) Coming from a physical chemist, this physical chemistry aspect of this "Comet origin" stuff will get some real air time.
2) I am neither a prolific reader, nor a writer while you are both. You are much more likely to finish writing something about this than I am.
3) If you think it extremely speculative, write a science fiction novel along these lines - If it needs some experimentation - give it as a possible project to a suitable student.
4) I may formally make it into a proper marconomic theory, but my motivations at the moment is to have you a) understand what I'm suggesting, and b) agree with me that it's not only plausible, but likely.