Evolving Thoughts

Evolution, culture, philosophy and chocolate! John Wilkins' continuing struggle to come to terms with impermanence... "Humanus sum, nihil humanum a me alienum puto" - Terence

Friday, November 11, 2005

Leading evangelist admits the Designer is God after all

And, what's more, the citizens of Dover, Pensylvania, in the USA, should know this, for they are no longer able to call on God in the case of a natural disaster, according to televangelist Pat Robertson, because they "just voted Him out" when they voted out all of the Intelligent-Design-proposing school board members in a recent election. These members were the folk who tried to get ID on the curriculum and have a disclaimer read about evolution to students, prompting the legal case that has just concluded. The judge's decision is due in January, so expect a major meteor strike in Dover about then.

Pat Robertson is the paragon of virtue who recently called for the assassination of the Venezuelan prime minister by the CIA.

So much for it being "religion free", as if anyone, in or out of the "Discovery" Institute, believed that. [Incidentally, when will the "Discovery" Institute actually discover something? If I had $20 million US per annum, I bet I could discover something.]

Wednesday, November 09, 2005

Terror "suspects", yeah, right

So a bunch of people, all Muslim, of course, have been arrested, planning according to the various police commissioners and politicians, to carry out a terror act.

Did they need terror laws for this? No. They were investigating these people for 18 months. They didn't need to hold them for longer than the usual period. So much for the "urgent legislation".

But that's not the problem here: the media were invited to film these raids (again), the pollies and the police have made public announcements - suppose one or more are innocent? What hope have they got? There are rules here people. They are suspects. No more, as yet. Stop the hysterical media coverage, and the authorities ought to keep the whole thing as quiet as is responsible. We need stronger sub judice laws, I believe.

More and more I have seen the rights and protections we struggled for years fall away as politicians, no doubt with the very best of intentions, use the terrorist attacks as a premise. They won already, the terrorists...

Own your own deity

On Ebay right now there is this:

All Proceeds are being donated to the NCSE so it's worth buying, not just for the benefits you will have in the afterlife. Become a Pastafarian now! It's a Pascal's Wager worth taking!

Charles Darwin has a posse

From the inimitable Colin Purrington comes this:

I note only that I will shortly be the same age as Darwin was when he published On The Origin of Species, that I am exactly the same height as he, and that I probably weigh about what he did. And, if I am lucky, I publish The Origin of Species Concepts sometime in the next year. I'll start work on the beard in the next few months...

Purely coincidental, of course.

Tuesday, November 08, 2005

Gavrilets continued

More from the nether regions of my cortex on the work and ideas of Sergey Gavrilets...

The idea that there are neutral networks - that is, ridges of nearly identical fitness value in the space of all possible genotypes for a species - suggests a way of reconciling two concepts that have been held to be opposed in the Darwin Wars: adaptation and drift.

This goes back to a debate between R. A. Fisher, who first successfully argued that Mendel and Darwin could be reconciled, and who proposed the "fundamental theorem" of selection (which is not a theorem), and Sewall Wright, who suggested that Fisher's theorem only applied to unrealistic populations (that were infinite and equally likely to mate between any two individuals), and that evolution in fact relied upon changes due solely to statistical or stochastic effects of sampling error in small populations. Wright, of course, is the inventor of the adaptive landscape. Fisher influenced the British evolutionists, while Wright influenced Dobzhansky and Mayr in America.

Mayr's account of speciation relied on the small population stochasticity of peripheral isolate populations of a species being subjected to fluctuations unrelated to selection for reproductive isolation. In effect, reproductive isolation was a side-effect of evolution in small populations. The British tradition of Haldane and Maynard Smith tended to ignore speciation and focus mostly on selection.

In Gavrilets' view, an adaptive landscape is almost always going to have roughly equivalent regions that are interconnected - that is, they form networks. But they are not selectively neutral networks - each point on the network pathway must be roughly the same fitness. In short, the networks are fitness ridges or contours along which species or populations will transcribe a "random walk".

Yep, that's right - both selection and drift are in play here. The fitness is maintained, but the populations will take random directions due to stochastic effects, for any realistically sized population. So speciation may be due to stochastic effects while selection maintains the current genotype at the local optimum. That is, in other words, the fitness isn't a peak, it's a ridge which is part of a series of interconnected ridges. Selection can only maximise local fitness, not where on the fitness ridge the population is.

Gavrilets uses a different metaphor, and I must point out that it is indeed a metaphor not a model, of a holey landscape, in which there is a high region of fitness in the landscape, interspersed with regions of low fitness (see figure). In the high fitness region, a random walk can take you all over the place. Of course, one thing Gavrilets insists upon is the high dimensionality of the space of fitness combinations - the 2-dimensional space here is a necessary limitation of paper.
So, what does this mean for speciation? More on this later. For now, I find this enormously interesting: that selection and drift are, in effect, decoupled. They aren't antonyms, they are just different processes.

That makes a lot of the argument between adaptationists and antiadaptationists otiose, I think.

More later

Monday, November 07, 2005

Meanwhile, in an alternate reality

I don't scare anyone, really

Here, courtesy Pharyngula (of course! Does Maeyieorhsz ever work?) is a test of how scary you are. Of course he's Hannibal Lecter in disguise - we didn't need no test to tell us that.

According to them, I am:

You Are Scary

You even scare scary people sometimes!

But I know that kittens laugh at me behind my back.