Thursday, July 10, 2008

Origin of Flatfishes: The Eyes Have It!

Flatfishes (Pleuronectiformes) are unusual in that they are asymmetrical, having both eyes on the same side of the head. The placement of eyes in young flatfishes is symmetrical, and the origin of this bizarre morphology has puzzled evolutionary biologists dating back to Charles Darwin. Unfortunately, the apparent lack of flatfish species that exhibit an intermediate morphology with regard to the placement of eyes has been a favorite of creationists as yet another example of "no intermediate form. " A paper published yesterday in Nature by Matt Friedman, a graduate student at the University of Chicago, blows this creationist example away by showing that fossil flatfish species dating from the Eocene (approx. 50 Ma) have an intermediate placement of the eyes on the head. Another important aspect of this study is that the evolution of this was not saltatory, but gradual. The work presented in this paper is an outstanding example of integrating fossil and extant lineages to discover the course of diversification in a trait, and how information from fossil lineages can inform phylogeny. There is some news buzz about this paper, and I was interviewed by the Chicago Tribune (my home town paper). Philippe Janvier wrote a very nice News & Views for this paper in Nature.

5 comments:

Jeremy said...

I saw Friedman present this at Evolution 2008, if I'm not mistaken. It's a really cool result - but it made me glad I'm a neontologist. I can't imagine putting in that much time looking at rocks under a microscope.

Glor said...

This is fucking beautiful.

Glor said...

Sandwalk discusses this research as well, and includes links to other discussions.

sergios-orestis said...

I was wondering if anyone was planning on posting something on this paper on HGT of antifreeze protein genes in fishes.

Graham LA, Lougheed SC, Ewart KV, Davies PL (2008) Lateral transfer of a lectin-like antifreeze protein gene in fishes. PLoS ONE 3(7): e2616.

Glor said...

Tom would be the man for a post on that!