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Welcome to Superoceras, a blog about science and natural history, slightly biased towards paleontology and zoology, but inclusive of all sciences. Started in October of 2009, my goal is to communicate scientific knowledge (and the occasional piece of nonsense) in an informative and entertaining manner. Feel free to contact me with questions, comments, concerns, or criticism at superoceras(at)gmail(dot)com, and follow me on Twitter @Superoceras for all that and more in 140 characters or less!

Wednesday, November 02, 2011

SVP 2011 (Day 1): Vertebrates in Vegas

A model of Rhabdoderma elegans, an extinct coelacanth, swimming through a Permian reef at the Smithsonian National Museum of Natural History.

There's nothing like starting your morning with a hearty does of vertebrate paleontology.  After the opening remarks, the first day of talks began.  I opted to spend some of my earliest time slots in talks on some of the earliest vertebrates during a symposium on fim and limb evolution.  The evolution of paired pectoral and pelvic fins in early vertebrates was a huge innovation.  It would eventually lead to the development of the tetrapod limb, which would be modified time and time again in different vertebrate lineages.  Looking at the arm of a human, the wing of a bird, and the flipper of a whale, one might not immediately see the similarities.  But if you look a little closer, you can see that they all have their roots in the paired lobe fins of a common sarcopterygian ancestor.  I'm not the most sentimental individual, but as I sat in those talks, and sit here now typing this with my extremely dexterous manual digits, I can't help but think about that ancestor, and pay my respects to all of the fins and limbs that came before mine.  Those early pioneers helped make the vertebrates one of the most successful groups of animals on the planet.

Skeletal reconstruction of the labyrinthodont Acanthostega gunnari, one of the earliest limbed vertebrates, on display at the American Museum of natural History.

And when it comes to successful vertebrates, there is no group more famous than the dinosaurs.  They were the dominant form of life on the planet for over 160 million years, and one lineage survived the mass extinction event 65.5 million years ago and is represented by myriad forms today.  There were some dinosaur talks during the first technical session, one of which is sure to sadden more than a few individuals who are still hoping to be able to resurrect a non-avian dinosaur from recovered soft tissues, proteins, or DNA.  Using new "metagenomic" techniques, researchers have been able to identify all the DNA in a sample of proposed dinosaur soft tissues, and have discovered that the majority of it is, in fact, not dinosaurian (Salzberg et al. 2011).  The presence of bacterial, plant, and fungal DNA seems to suggest that there is a very small chance that any of the soft tissues previously recovered are actually from a dinosaur.  And the chordate DNA found in the sample is likely the result of sediment leaching, as more of it was mammalian than avian.  That being said, they did find some chicken DNA in there as well, posing the question as to whether it belonged to a modern bird and was also present as a result of leaching, or whether it is the original dinosaurian molecules, preserved for millions of years.  I think the odds of it belonging to a modern neognathan are pretty strong given the evidence, but a reevaluation of the soft tissue work done in previous years, and future research, may still yield indisputable non-avian dinosaur proteins.  One can only hope!

If you're looking for dinosaur DNA, Gallus gallus may be your only best source.  A silver laced Wyandotte, photographed at the Nashville Zoo at Grassmere.

More afternoon talks and a some really great posters preceded a fantastic welcome reception with a gorgeous view of the city after dark.  I was happy to catch up with some old friends, and be able to meet some of the people I interact with online in person.  All and all, I think things are off to a great start, and I'm looking forward to the rest of the week!



Referenced Talks


Symposium 1: To Fins, limbs, wings and back again. Presented at the 71st Annual Meeting of the Society of Vertebrate Paleontology, Wednesday, 02 November, 2011, from 8:00AM-12:15PM.


Salzberg, S., Novak, B., Poinar, H., andKaye, T., and MacCoss, M.  2011. DNA, dinosaurs, and metagenomics: A new tool for mass identification of DNA from fossil bone.  Presented at the 71st Annual Meeting of the Society of Vertebrate Paleontology, Wednesday, 02 November, 2011, at 9:15AM.

2 comments:

  1. Gallus gallus may be one of the most readily accessible, but certainly there are many other species of extant dinosaurs one could get a DNA sample from!

    ReplyDelete
  2. You are absolutely correct. I chock that oversight up to trying to get this post out in the 30 minute break I had that day. But really, it's unacceptable. CORRECTED.

    ReplyDelete