Numero, pondere et mensura

Scientific reflections on nature, design, life

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I am an assistant professor in the biomedical field with an interest in developing scientific design arguments

Saturday, May 06, 2006

Whoops!!!

Wow, I almost forgot about my little experiment here! I got sidetracked helping my graduate student with her April 5th postdoctoral grant. Everybody in the lab had to put their stuff on hold for a couple weeks while we pitched in. Looks to be a dynamite project and the application is much more competitive due to everyone's help. Now that things are settling down, perhaps I can get back to blogging! Stay tuned...

Tuesday, March 28, 2006

commenting and trackback have been added to this blog.

Thursday, March 23, 2006

Arachn-ad-hoc

Yesterday I mentioned evolutionary ad hoc explanations. Darwinists are real experts at those. Give them anything in life, and they can come up with a just-so story about how evolution created it out of nothing. They get particularly creative when it comes to "explaining" behavior. "Evolutionary psychology" is full of these stories, many of them so far-fetched that even other Darwinists criticize the field.

The latest entry in the tall-tale contest is "Snakes as agents of evolutionary change in primate brains" by L.A. Isbell in the Journal of Human Evolution.

This article says that spending time with poisonous snakes is responsible not just for fear of snakes, but for much of our brain organization, including our visual pathways and their integration with grasping. I guess "It makes sense to design our brain so that we can see what we touch and touch what we see" doesn't make a good enough story.

To see how badly this "evolutionary psychology" tale fails, think of spiders instead of snakes. Spiders creep people out almost as much as snakes to, but they are practically harmless. There are only a few species that even have the capability to be dangerous, and they live where people rarely interact with them. Most of the wounds that people call spider bites are really just minor scratches that got infected. Maybe, just maybe, spiders could kill as many as one person in a million. That is hardly enough to cause an instinctive fear to evolve.

Yet, most people have the same innate fear of spiders (arachnophobia) as they have of snakes. Evolutionarily it doesn't make sense to evolve complex behaviors for extremely low danger situations. Fear of big mammals with sharp teeth? You bet. Fear of spiders? Nonsense.

However, under a design perspective, even a small risk may be worth avoiding. We design airplanes with floation devices under the seats, even if far less that one in a million travelers ever need them. Design is more far-sighted, and cautious, than evolution. And more effective, too.

Wednesday, March 22, 2006

Designing cell circuitry

There is a great article in Nature today. The title "An excitable gene regulatory circuit induces transient cellular differentiation" already gives away the store. The authors show how a bona fide gene regulatory circuit works in bacteria. Why is this a big deal? Bear with me.

One problem cells have, especially prokaryotic cells, is how to regulate gene expression through the molecular machinery that controls RNA transcription and translation. The problem lies in the cell's limited size: because cells are so small, most protein molecules (including gene-regulatory transcription factors) are expressed in limited numbers. And when molecules are expressed in small numbers, they are subject to wide stochastic fluctuations in concentration: at any give time, a cell can have many, a few, or none of the molecules required to regulate a gene set. Not good for reproducible cell function.

Enter the design-theoretical perspective: one can reason that, since they exist, perhaps stochastic fluctuations are an inherent part of the system. Indeed, the authors use this perspective (I am not sure whether subconsciously or intentionally) to figure out that, indeed, specific gene circuitry can be built in the presence of underlying stochastic fluctuation. Not only, but the gene circuitry takes advantage of the underlying stochasticity for robust function. The authors even extract the basic mathematical design principle for the circuitry function, and reverse-engineer it (which makes me think that their application of design principles may be intentional, although of course cannot be explicitly stated in a Nature paper). Impressive.

But this is not all. Think now of the daunting task blind, non-guided natural selection processes would encounter doing the same thing. In order for the cell to work, and for gene expression stochasticity to be under control, specific circuitry has to be in place. On the other hand, the circuitry has to "build itself" from scratch in a pre-existing cell in which stochastic gene expression would be continuosly disrupting all sorts of essential functions. Hard to believe.

Sure, biologists working under a strict Darwinist approach may come up with some ad hoc, post-facto theoretical models about possible, but ultimately unprovable evolutionary pathways to this kind of system. However, design-based explanations clearly have the advantage, and show their power in this study.

Why Do This?

Can a blog like this really get me in trouble? Perhaps. Is it worth it? I think so.

It is hard to explain if you don’t experience it, but there is a sort of existential loneliness when you are a biologist with an interest in design. After all, science is useless without sharing, and it’s more than something you learn, it’s who you are. Sometimes you have a feeling some other faculty you meet may have similar ideas (in fact, I am almost positive several do, even at a prominent mainstream institution like mine), but you are afraid to breach the topic. In my case, I might be safer than most – my own department head has once mentioned a known design scholar without the usual ritualistic dismissal or disdain – but you just never know.

So, I hope to use this blog for sharing my science, and that someone will read it. I will work hard so that my posts will sound committed but not dogmatic, enthusiastic but rigorous.
Stay tuned.