Output Stream of Consciousness

Link: http://evolutionanddesign.blogsome.com/2006/07/10/as-an-update/#comments

(A side note: I know there's a lot of jargon in here. One of these days, I'll have to tackle one jargonesque term at a time and try to bring it to a public level. In the meantime, if there's something that looks interesting but total Greek, just ask)

A member of the NCSE, Nick writes some pretty thorough, thoughtful things on evolutionary theory. He's responsible for such dissections of creationist and intelligent design thought as Icons of Obfuscation.

Here (comment #11) is a spirited screed by Nick on misunderstandings of the scale of some of the conflicts inside evolutionary theory, and in particular, misunderstandings of Richard Dawkins somehow dogmatically "not getting" some of these issues.

Punctuated Equilibria, or "periods of rapid evolution", and also colloquially known as "Punk Eek", was one conflict between Dawkins and Gould that was blown somewhat out of proportion.

Nick:

First, “gradualism” is not in opposition to Punk Eek. Punk Eek is really a gradualist model of speciation, based upon applying Ernst Mayr’s model of geographically localized speciation (”allopatric speciation”) to the fossil record. Ernst Mayr, you may recall, was not some revolutionary against the NeoDarwinian modern synthesis — instead, he was the personification of and leading proponent of the Modern Synthesis. Gould and Eldredge simply took his model and applied it to the fossil record to explain the common (but not universal) pattern of stasis in a species followed by “rapid” (10,000 - 1,000,000 years “rapid”) change to another species...

...What Punk Eek actually opposed was “constant rate-ism”, as in fact Dawkins rather carefully explains in The Blind Watchmaker.

I've read The Blind Watchmaker, and indeed, Dawkins "gets it".

Another issue that Nick deals with is the "fuzzification of the tree of life". Since bacteria can actually transfer genes back and forth to one another, this could muddy up the waters some. It's not as though that hasn't been taken into account, though.

Responding to:

there is no “one true tree of life”.

This is wrong to a high degree of statistical approximation. Sure, there are exceptions like hybridization in plants and lateral gene transfer in microbes, but overall the tree pattern of life is extremely rigorously documented, and the specific tree scientists have constructed is continually supported by new data, although of course minor revisions are continually ongoing. The statistics of comparing the similarity of phylogenetic trees are important to understanding this; rather than reinvent the wheel, I refer everyone to this extremely excellent page on the topic, especially the subpage on Statistical Support for Phylogenies.

Talking about the 'tree of life', this is the view of common descent, that all life on the planet (that we have found so far) are the surviving descendents of one or a small pool of organisms. We don't know what went on before that, because all no other distant cousins to it have left any surviving descendents. The 'tree' analogy is because the lineages of those organisms' descendents have been branching and branching (and mostly eventually going extinct) ever since.

To further quote Nick:

To continue in my curmudgeonliness here, if one going to brazenly include things like “hybridization” and “good old sex” as violations of the “Tree of Life” paradigm, then one is clearly just setting up a silly strawman of what the “Tree of Life” paradigm is, probably for the purposes of knocking it down to show how amazingly revolutionary and open-minded one is...

There's a lot of good meat in the rest of the article.

Gads, I am envious of the people who can put that much thought and detail into their postings :) Thanks for a good post, Nick!