Showing posts from August, 2009

The origin of malaria

Here's a interesting bit from PNAS a couple weeks ago:

One of the mysteries of creation is the origin of natural evil. We know that some of it came directly from the Curse (e.g., weeds), some probably from degradation of an initially perfect condition, and some from what I've called redesign - the needed re-configuring of creation and ecology to accommodate animal death. In the latest Answers magazine, Joe Francis distinguishes three possible origins of natural evil: modification, uncontrolled growth, and displacement - the movement of creatures or substances out of their intended environment, which can cause pathology. It would be nice if examples of natural evil followed one model of origin or another, but sometimes, it gets complicated.

The Plasmodium genus is one such complicated case. Plasmodium parasites need to get inside eukaryotic cells in order to complete their life cycles. If they would just do their business quietly, it would probably be no big deal, but when a…

Buffon hated cats

I picked up a copy of Buffon's Natural History (the Barr translation from 1797) for the CORE library recently. I've already enjoyed flipping through the volumes, but I was surprised to read his opinion of the ordinary house cat (from vol. VI, pp. 1-2):
The cat is a faithless domestic, and only kept through necessity to oppose to another domestic which incommodes us still more, and which we cannot drive away; for we pay no respect to those who, being fond of all beasts, keeps cats for amusement. Though these animals are gentle and frolicksome when young, yet they even then possess an innate cunning, and perverse disposition, which age increases, and which education only serves to conceal. They are naturally inclined to theft, and the best education only converts them into servile and flattering robbers; for they have the same address, subtilty and inclination for mischief or rapine. Like all knaves they know how to conceal their intentions, to watch, wait, and choose opportu…

Retrotransposition during brain development

I'm not sure just what to make of this report from the latest Nature, but it's pretty interesting stuff for us transposable element fans:

L1 retrotransposition in human neural progenitor cells
Coufal et al. 2009. Nature 460:1127-1131.
Long interspersed element 1 (LINE-1 or L1) retrotransposons have markedly affected the human genome. L1s must retrotranspose in the germ line or during early development to ensure their evolutionary success, yet the extent to which this process affects somatic cells is poorly understood. We previously demonstrated that engineered human L1s can retrotranspose in adult rat hippocampus progenitor cells in vitro and in the mouse brain in vivo. Here we demonstrate that neural progenitor cells isolated from human fetal brain and derived from human embryonic stem cells support the retrotransposition of engineered human L1s in vitro. Furthermore, we developed a quantitative multiplex polymerase chain reaction that detected an increase in the copy number of …

Hello, patch-nosed salamander

Sometimes, I wish I were a little more observant of my surroundings. Back when I first arrived at Bryan, there was a new species of plethodontid salamander described from the Cumberland plateau, which is literally in my back yard. It was just a cryptic species from the mountain dusky species complex (Desmognathus abditis for those in the know), so I probably wouldn't have recognized it as a new species even if I'd found it.

In a recent issue of the Journal of Zoology, Camp et al. [PDF] describe not only a new species but a whole new genus that is very distinct from other plethodontids. They call it the patch-nosed salamander, with the tongue-twisting formal name Urspelerpes brucei (the genus means roughly "original cave crawler"). That's Urspelerpes in the picture above. According to Camp et al.'s phylogenetic analysis, this is the sister taxon to the entire Eurycea genus. Strangest of all? It was found in northern Georgia, which isn't exactly my ba…

A fully functional vestigial organ?

Creationists get pretty excited about vestigial organs. A search for vestigial in CELD gives 28 hits, with articles about horse muscles, male nipples, and several about the appendix, that little dangly thing on your large intestine (provided you still have one). It's not surprising that this would be the case, since I've always thought the evolutionary case for vestigial organs has been overstated. Early on, zealous evolutionary biologists made up lists of vestigial organs that, for the most part, were merely organs of unknown function. They just ignored the standard canon, "Absence of evidence is not evidence of absence." Such mistakes made for easy - and justifiable - targets for creationist arguments.

A more subtle mistake is the insistence that vestigial organs have no function, that they are true evolutionary leftovers that are just waiting to be eliminated from our bodies. This leads to the equally fallacious response that by demonstrating a function - any…

Headline miscellany

I'm still on my quest to catch-up from my lazy summer, so here are a few interesting headlines for Friday:

A recent paper in Evolution by Lynch and Wagner looked at oviparity and phylogeny in sand boas, Did Egg-Laying Boas Break Dollo's Law? Phylogenetic Evidence for Reversal to Oviparity in Sand Boas (Eryx: Boidae). From the abstract:

We reconstruct ancestral parity mode on this phylogeny and present statistical evidence that oviparity re-evolved in a species of Old World sand boa in the genus Eryx nearly 60 million year after the initial boid transition to viviparity. Remarkably, like other viviparous boas hatchlings of oviparous Eryx lack an egg-tooth providing independent evidence that oviparity is a derived state in these species.
That is indeed remarkable. Or is it mediated design? I don't know, but it's probably worth looking into.

Today's Science has a report about dog legs. Remember my ongoing argument that mendelian genetics is not enough to explain post-…

Name that critter

Still ploughing through my backed up email, and here's a little essay by Carol Kaesuk Yoon that Joe Francis alerted me to. I really like it. It echoes a lot of themes from Understanding the Pattern of Life, but it also introduced me to the wonderful term daffodility. I shall use that in my classes from now on.

Reviving the Lost Art of Naming the World

Sounds like I should get her book Naming Nature: The Clash between Instinct and Science.

It's been a while...

Yes, I know I've been a bit out of the loop the past month or two. I re-discovered this thing called real life, which I found is far more enjoyable than anything online. Imagine that. I've been sitting on my porch drinking IBC root beer and watching the horses across the road. I went home to visit my parents and picked blackberries, which were so ripe they burst and squirted juice all over me just from picking them. Cool stuff like that.

Anyway, while I've been enjoying my break from the cares of the creation/evolution debate, there have been some things happening. Last week, Bryan College was mentioned in an article in US Today about creationism and theistic evolution. Some people asked my opinion, so here it is: It's not very flattering, but it's nice to be recognized as a leader in the field.

Meanwhile, this passage from James 4 was mentioned in faculty workshop this morning, and it reminded me of the endless debate between young-age creationists and theis…

Odd ode to Lamarck?

I'll never forget my first visit to the Jardin des Plantes in Paris. I had been reading a lot of Cuvier before visiting, and I naively expected that there would be some kind of statue to him in the park. I found two statues on the grounds: Buffon at the south end and Lamarck at the north. Cuvier was reduced to a single bust in the Gallery of Comparative Anatomy and Paleontology (well worth visiting, by the way). So much for the father of paleontology.

The statue of Lamarck is labeled, "Fondateur de la doctrin de l'evolution." (Of course, French pride certainly couldn't let Darwin have that title.) In the latest issue of Nature, however, Dan Graur, Manolo Gouy and David Wool published a review of Lamarck's Philosophie Zoologique on the occasion of the 200th anniversary of its publication. As my regular readers know, I am all for setting the record straight, but I have to admit that I found Graur et al.'s review a little hard to swallow in spots.

Not h…

BSG wrap-up

Thanks again to all the speakers and participants who made the 2009 BSG conference another success. I heard several good comments from our "old faithfuls," who really felt this was an excellent meeting. I certainly enjoyed the red velvet cake, not to mention the presentations. And I learned about ooids (one of the perks of meeting with geologists).

I also wanted to announce the change in the BSG's Executive Council. At our annual business meeting, Georgia Purdom of AIG was elected to the EC. Leaving us is Marcus Ross, who I understand is assuming new responsibilities (secretary?) with the Creation Geology Society.

Looking ahead, the 2010 BSG/CGS conference will be at Truett-McConnell College on July 28-30. Start thinking now about projects and abstracts you could present. As always, abstracts will be due at the end of March. We hope to see you there.