bicoid evolution

PZ, I have been working on a paper on bicoid and ID, since Paul Nelson uses bicoid as an example of Biological Specification in his mere creation paper.

There’s a telling experiment that reveals how trivial the function of nanos is. We can make flies in the lab that lack maternal nanos. We can make flies that lack maternal hunchback. We can make flies that lack both maternal nanos and maternal hunchback, and here’s the kicker, these flies produce embryos that develop completely normally. Maternal hunchback RNA is a mistake, a sloppy bit of unnecessary secretion that does nothing for the embryo, and maternal nanos is an elaborate, Rube-Goldberg mechanism that has been patched in to correct the stupid mistake.

Now if I were an intelligent designer building a fly from scratch, and I saw this little design defect, the way I would correct it is the obvious one: I’d fix the fly ovaries so that they weren’t dribbling a completely useless protein into the egg. I wouldn’t assemble a complex of a half-dozen proteins that were integrated into the cytoskeleton and pump a hunchback-suppressor to the right place, with other proteins floating around to make sure my hunchback-suppressor didn’t do damage in the places where hunchback is supposed to be turned on.

Absolutly fascinating. So it appears that the designers are fallible and capable of making mistakes? Perhaps (they?) are a bit like Microsoft, quick get the product out and then issue patches for the mistakes.