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Quintessence of Dust

Quintessence of Dust explores science, society, and human nature, focusing on genetics, development, evolution, neuroscience, systems biology, and topics related to scientific literacy. I occasionally discuss intelligent design, creationism, science denial, and other political/social influences on scientific literacy. Additional topics: philosophy, baseball, scientific culture, and Shakespeare. My main theme is scientific explanation.
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BiologiaInglese
Pubblicato
Autore Stephen Matheson

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...

AdaptationFitness LandscapeSelectionBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

Common DescentDevelopmentGeneticsBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

Common DescentDevelopmentGeneticsPeer-reviewed Blog PostBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

Common DescentDevelopmentBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

AdaptationFitness LandscapeGeneticsVariationBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

Communicating ScienceBiologiaInglese
Pubblicato
Autore Stephen Matheson

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.

DesignGenomeJunk DNABiologiaInglese
Pubblicato
Autore Stephen Matheson

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.