Wednesday, August 15, 2007

Overselling Genomics Award #2

Well, all I can say is "Aaaaargh" again. So I am awarding my second overselling genomics award to a Press Release from U. Florida entitled "Conquest of land began in shark genome" relating to a paper in PLoS One on shark development . The press release centers on a reported finding that
Using molecular markers to study the formation of skeletal cartilage in embryos of the spotted catshark, UF scientists isolated and tracked the activity of Hox genes, a group of genes that control how and where body parts develop in all animals, including people.
Now admittedly, this is not genomics here - but the press release just had to use genomics in the title so my automated google search for "genome" and "evolution" picked it up. So - why do they get the overselling award? Read more in the press release:
The finding shows what was thought to be a relatively recent evolutionary innovation existed eons earlier than previously believed, shedding light on how life on Earth developed and potentially providing insight for scientists seeking ways to cure human birth defects, which affect about 150,000 infants annually in the United States.
Yes that is right, this genome-ish gene expression study in sharks is going to help cure human birth defects (note the paper in PLoS One seems entirely reasonable ... this is another case of press releases being disconnected from the science - and is another reason to support OA publications because here you can actually all go and read the paper and ignore the press release).

In addition, the press release says
“We’ve uncovered a surprising degree of genetic complexity in place at an early point in the evolution of appendages,” said developmental biologist Martin Cohn, Ph.D., an associate professor with the UF departments of zoology and anatomy and cell biology and a member of the UF Genetics Institute. “Genetic processes were not simple in early aquatic vertebrates only to become more complex as the animals adapted to terrestrial living. They were complex from the outset. Some major evolutionary innovations, like digits at the end of limbs, may have been achieved by prolonging the activity of a genetic program that existed in a common ancestor of sharks and bony fishes.”
Now I accept that the specific details of Hox gene expression here might have been surprising but what friggin evolution textbook are these people reading if they are surprised that there is not a chain of life going from less complex to the pinnacle of complexity in humans? Hopefully not mine.


  1. I am glad you picked up on this one, as it was also irritating for me. The "Overselling Genomics Awards" are great. No shortage of nominees, unfortunately.

  2. As a timely confirmation of why the press release is bad, this was picked up at Uncommon Descent as an example of front-loading.

  3. In defence of Marty Cohn (who I know slightly), this is in the context, as stated in the abstract, of the absence of the later expression in the zebrafish. Since zebrafish are not only newer evolutionarily than sharks but has more complex fins this is surprising. It will of course be nice to repeat this in lobe finned fish but since embryos and adults are scarce and not amenable to laboratory science I cannot see this being done soon.

    So since the starting state of the science is no later Hox expression in teleosts this is a most interesting paper. Having worked in the lab Marty did his PhD in and having published in limb development I do not share your cynicism wrt Marty's quoted words, though the rest of the press release is clearly a beat up, though not a large one IMHO.

    Peter Ashby

  4. Peter

    I sympathize with your defense of Marty Cohn. As I said "note the paper in PLoS One seems entirely reasonable". The issue I have with Marty's quote (and I guess some of your comments) is that they imply that everything progresses from simple to complex, which is simmply not true. In addition, this type of comment implies that no evolution has happened in lineages with ancestral features. This is also not true --- just because they look more ancestral (and in this case, perhaps simpler) in their gene expression does not mean that nothing has changed in the underlying molecular biology since they separated off as a distinct branch

  5. Maybe you should send the press authorities your textbook to replace the Of Pandas and People that must be their primary reference.

  6. I pondered doing that - sending out my book. But then I remembered Cold Spring Harbor only gave me 12 copies and I have already given away many of them. So maybe I will send the press people a link to Amazon for evolution books instead.