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.

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.

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;

Almost two years ago, I reviewed Michael Behe's latest book, The Edge of Evolution, here on the blog. I was unimpressed, to say the least, and remain of the opinion that Behe should not be considered a serious scientific thinker given his failure in that ludicrous book.

Welcome to Quintessence of Dust and to the 14th Edition of the monthly Carnival of Evolution. Thanks for stopping by, and for supporting scientific carnivalia, members of a taxon that seems to be flirting with extinction. One good reason to visit a carnival: brain stimulation.

Consider these not-so-random samples from the animal world: a cockroach, a zebrafish, a mouse. What do these creatures have in common? Left to right: American cockroach (Periplaneta americana), zebrafish (Danio rerio), house mouse (Mus musculus). Cockroach image from Wikimedia Commons, zebrafish and mouse from Wellcome Images. Well, they're all animals and that means they're all eukaryotes, for example. They all have DNA-based genomes.

Hello and welcome to the 28th edition of the genetics blog carnival known as Mendel's Garden, where we celebrate blogging on topics related to anything touching on what Mendel discovered (or thought he discovered). While reading these interesting and informative pieces, please think about work that should be featured in a future edition and/or blogs (like yours) that would serve well as future hosts. So do tomato seeds get you excited? No? Oh.

Mendel's Garden is a genetics blog carnival overseen by Rich over at evolgen. The new edition is up at Another Blasted Weblog and there's some excellent stuff in there, including some very Mendelian tidbits. Next month's edition will be right here at Quintessence of Dust.