Welcome to the 34th Edition (1 April 2011) of the Carnival of Evolution, and welcome to Quintessence of Dust. It's nice to be hosting this fine carnival, and to see that it's still going strong. I've organized the carnival under some chapter and section headings that I got from some old Victorian's magnum opus, but I think you'll find the topics require no further creative embellishment. Continue reading...

A couple of months ago we started looking at the concept of fitness landscapes and at some new papers that have significantly expanded our knowledge of the maps of these hypothetical spaces. Recall that a fitness landscape, basically speaking, is a representation of the relative fitness of a biological entity, mapped with respect to some measure of genetic change or diversity.

Given that disputes over the existence and meaning of the phylotypic stage and the hourglass model have simmered in various forms for a century and a half, the remarkable correspondence between the hourglass model and gene expression divergence discovered by Kalinka and Varga and colleagues would be big news all by itself. But amazingly, that issue of Nature included two distinct reports on the underpinnings of the phylotypic stage.

The controversy about the existence of the phylotypic stage is more than some bickering about whether one blobby, slimy fish-thing looks more like a Roswell alien than another one does. It's about whether the phylotypic stage means something, whether it tells us something important about development and how developmental changes contribute to evolution.

Disputes and controversies in science are always a good thing. They're fun to read about (and to write about), and they're bellwethers of the health of the enterprise. Moreover, they tend to stimulate thought and experimentation. Whether scientists are bickering about evo-devo, or about stem cells in cancer, or about prebiotic chemistry, and whether or not the climate is genial or hostile, the result is valuable.

Thinking about fitness landscapes can stimulate detailed discussion and consideration of the meanings and limitations of such metaphors, and my introductory comments at The Panda's Thumb did just that. Most notably, Joe Felsenstein pointed us to the various ways these depictions can be employed, and urged everyone to use caution in interpreting them.

The concept of a "fitness landscape" is a fundamental idea in evolutionary biology, first introduced and established during the so-called "evolutionary synthesis" in the early 20 ^th century.

And so, last week, some of my friends from BioLogos and Calvin College participated in this Vibrant Dance thing. These are people I hold in very high regard, people pursuing goals that I consider to be among the most important projects a Christian scientist can tackle.

Christian unity is not something to take lightly. Famous biblical proof texts urge us to pursue it. Basic theological commitments establish it as a primary goal of believers. Basic human nature would seem to drive us to seek solidarity with those who share fundamental beliefs.

Last month, PZ Myers wrote an interesting piece at the Panda's Thumb in which he discussed some problems with very simple models of evolutionary genetics. One of his main themes was the idea that many genetic changes are neutral with regard to fitness;

So why is it that I and many other biologists hypothesize that introns are mostly non-functional? (I'll assume that you've read the previous posts, and that you understand what it is that I mean when I challenge claims that introns are functional elements in an information-rich genome.