Monthly Archives: December 2008

Natural selection at work

Posted on by

Roger Alsing has written a genetic algorithm – a computer simulation of evolution via random mutation and “natural” selection – that recreates the Mona Lisa. It achieved a pretty good replica layering only 50 semi-transparent polygons of various colors, in just shy of a million generations. And it got pretty close in the first hundred thousand generations; a neat example of R. A. Fisher’s “geometric model” of evolution toward an optimum, in which evolutionary change slows as the distance to the optimum decreases.

Via kottke.org and BoingBoing.

(Considerable debate on the BoingBoing thread about whether this is “really” evolution, since there’s a preordained optimum – I’m going to to say that it is, in fact, evolution. Specifically, a single bout of adaptive, directional evolution towards “Mona Lisa”-ness. The equivalent of which happens all the time in nature, except that usually the selective optimum shifts from “Mona Lisa” to “Les Demoiselles D’Avignon” after a million years or so.)

Well, that’s different

Posted on by

In Catalonia, it’s a deeply entrenched tradition to make a very specific kind of addition to public Nativity scenes:

Statuettes of well-known people defecating are a strong Christmas tradition in Catalonia, dating back to the 18th century. Catalonians hide caganers in Christmas Nativity scenes and invite friends to find them. The figures symbolize fertilization, hope and prosperity for the coming year.

Via P.Z. Myers at Pharyngula, who points it out for his own doubtless nefarious purposes.

Revelation by God, but through a man

Posted on by

Islamic scholar Abdulkarim Soroush thinks the Koran should be viewed in historical context, and as the writing of a human being (albeit a divinely inspired one) rather than the transcribed word of God.

[Soroush] told me that the prophet “was at the same time the receiver and the producer of the Koran or, if you will, the subject and the object of the revelation.” Soroush said that “when you read the Koran, you have to feel that a human being is speaking to you, i.e. the words, images, rules and regulations and the like all are coming from a human mind.” He added, “This mind, of course, is special in the sense that it is imbued with divinity and inspired by God.”

As might be expected, this hasn’t endeared Soroush to conservative Muslims. But it’s an encouraging line of thought. Precisely this kind of thinking about the Bible has led Christianity to an understanding of the text that is, I’d argue, more in line with what its authors understood it to be: a collection of accounts by fallible humans seeking the divine. In this light, scripture (whether the Bible, the Koran, or something else) is not taken at face value – it forces the reader to engage the text, and decide what it means to him or her, today. That’s no impenetrable firewall against extremism, but it’s an important first step.

Snail trails lead toward speciation

Posted on by

ResearchBlogging.orgFinding a mate is at the top of just about every to-do list in the animal kingdom. This might involve following the smell of pheromones or triangulating the source of a mating call; in the snail Littorina saxatilis, it turns out to require tracking your beloved by the trail of her slime [$-a].

That’s according to a paper in the latest issue of Evolution, in which Kerstin Johannesson and coauthors took video of male and female snails to catch slime trail-following in action. And it occurred to them that slime-following could be a component of speciation in L. saxatilis. This particular snail comes in two forms, or “ecotypes”: a small one that lives in the crevices of exposed rock faces and a larger one that lives in quieter, sheltered pools. When Johannesson et al. presented male snails with slime trails from each ecotype, the males preferred to follow trails made by females of their own ecotype.

This is what’s called assortative mating – preferentially mating with similar individuals – and it’s usually thought of as a first step towards speciation. Whether L. saxatilis ever eventually evolves into two species is another question, though. The world is full of experiments in speciation, where adaptation to local conditions or difficulty moving between populations can cause a species to begin diverging. But it’s just as likely that the forces pushing a species apart will change or disappear, and diverging groups re-merge into a single interbreeding population. Part of the fun of studying the natural world is finding things like snail’s slime trail discrimination, and trying to figure out what will happen next.

Reference

K. Johannesson, J.N. Havenhand, P.R. Jonsson, M. Lindegarth, A. Sundin, J. Hollander (2008). Male discrimintation of female mucous trails permits assortative mating in a marine snail species Evolution, 62 (12), 3178-84 DOI: 10.1111/j.1558-5646.2008.00510.x

Mennonites and Barack Obama

Posted on by

In this week’s Mennonite Weekly Review, Steve Kriss confesses to something traditionally un-Mennonite: having a political position. Specifically, in favor of Barack Obama. This is awkward both because Steve is a pastor, and has to be in pastoral relationship with people across the political spectrum, and because of the compromises necessary when you have to vote for one of two candidates. And what do you do when the guy you backed because of religious principle wins?

I am wondering how the Anabaptist message might be relevant in this changing world. Who are we becoming, and who might we become, in an America that elects Obama as president? Will we have more “Esther moments” of speaking truth to power? Or is it a time to renew the tradition of separation from the world?


Photo by BarackObama.com.

And from a Mennonite perspective, there’s a lot to like about Obama (especially, I would say, in contrast to John McCain; but that’s another argument). He favors applying government resources to social programs, but is friendly to working with “faith-based” groups to do so; opposed the war in Iraq from the start, and favors diplomacy over military force; and seems to have a genuinely reflective personal faith. And, of course, Obama represents a transcendence of American culture and racial barriers that Mennonites have long aspired to, if not achieved.

But Obama isn’t Mennonite. He opposed the invasion of Iraq because it was a stupid move, not because he’s opposed to war in all its forms. He practically channeled George W. Bush during the campaign, talking about what he wants to do to Osama Bin Ladin. An Obama administration will be more peaceful than the Bush administration, but that’s like saying Obama is taller than a hobbit. Mennonites, and members of the other historic peace churches, will still have a role in witnessing to peace.

Conscientious objection in Israel

Posted on by

All Israelis, men and women, are required to serve in the national military when they turn 18. That’s a hard social background within which to be a conscientious objector, even before you account for the fact that refusal to serve means jail time. Yet there are Israeli COs. On the God’s Politics blog, Howard Zinn introduces a campaign on behalf of one cohort of teenage COs, the Shministim. (That’s Hebrew for “twelfth-grader” – can you imagine going to jail for your beliefs as a high school senior? Yeah, neither can I.) The American-based Jewish Voice for Peace is looking for people to sign a statement calling for the Shminstim to be released, to be delivered to the Israeli Minister of Defense as one big pile of postcards on 18 December. Sign the statement here.

Speculative fiction no longer?

Posted on by

Gattaca has just been posted in full on Hulu. It’s one of my favorite science fiction films, a distopia in which genetic engineering divides the world into biological haves and have nots, and everyone’s life is decided at birth, based entirely on their genes.

In unrelated news, a company in Boulder, Colorado, has just started offering to test children for a genetic marker associated with different kinds of athletic performance.