Showing posts from 2013

Grad Publication: Dave DeMar

A paper coauthored by UW Biology graduate student Dave DeMar was recently published online in the journal Palaeobiodiversity and Palaeoenvironments. Dave's paper with coauthor James (Jim) Gardner of the Royal Tyrrell Museum of Palaeontology stemmed from a symposium entitled "Insights from the Fossil Record into the Evolution of Extant Amphibians and Reptiles", which was part of the Seventh World Congress of Herpetology held in August 2012 in Vancouver, British Columbia. Jim and Dave's paper is a comprehensive chronological review of fossil lissamphibians (frogs, salamanders, caecilians, and albanerpetontids) from North America that lived during the age of dinosaurs (Mesozoic) and the first epoch (Paleocene) following the demise of non-avian dinosaurs at the end of the Cretaceous. Their review, which is based on more than 400 published and unpublished accounts from 61 geological formations, is complemented by two plates illustrating several impressive lissamp…

Grad Publication: Melissa Eng

This is my first blog post but I hope to contribute more in the future (about my work on dendrite maintenance in the Parrish laboratory). Today’s post is about the work I did prior to starting graduate school at UW.         Once upon a time I joined Amin Ghabrial's laboratory at the University of Pennsylvania as a technician. Before that, I honestly had not given much thought to tubes. I remember the first time a straw failed me (it had a hole in it), and I remember feeling rather betrayed. Luckily straws are replaceable; the tubes running through our bodies though are not, therefore we better learn about and take good care of the ones we have.
        Some of the most important tubes in the human body are the capillary tubes that allow for separation of blood and brain fluid (known as the blood-brain barrier). In Cerebral Cavernous Malformation, a hereditary disorder that causes migraines, seizures, and even stroke-induced death, this barrier is compromised as a result of dilated a…

Grad Publication: Brandon Peecook

‘Non-dinosaurian dinosauromorphs’ certainly has a poetic ring to it. It’s the name given to the phylogenetic grade of animals more closely related to dinosaurs than to pterosaurs, though not quite dinosaurs themselves. Why aren’t they dinosaurs? Well, to be a dinosaur you have to be in the defined boundaries of Dinosauria, which means in the group of animals containing Passer domesticus (house sparrow) and Triceratops horridus, their most recent common ancestor and all of its descendants. To get in you need morphological character states. If you really want to know all the character states that may define Dinosauria let’s go to Schultzy’s for a beer, but suffice it to say it’s all in the hips (and humeri and tibiae and ankles). Compared to the true dinosaurs, of which there are well over 1,000 extinct species and over ~10,000 living birds, the non-dinosaurian dinosauromorphs are relatively unknown. The species we have fossils for all lived in the Triassic Period (252-201,000,000 year…

Grad publication: Mike Dorrity

The June issue of Plant Physiology features work I did in my previous lab at University of California, Davis. It's all about root development, and the main question it asks is: what is the genetic architecture underlying the length, angle, and cellular structure of the developing root? M82 and S. pennellii images courtesy of TGRC. In other words, what groups of genes are responsible for controlling a complex, pleiotropic trait like root length? We investigated this using two species of tomato; a domesticated breed (M82) and a wild relative (Solanum pennellii). S. pennellii is native to the coastal cliffs of Peru, and you may not even recognize it as a tomato relative considering how much time we’ve spent breeding varieties with the plump, red fruits we love (see photo). We’re talking centuries upon centuries here. The seedling root morphologies of these two species differ especially; M82’s roots are much longer than its wild relative, and S. pennellii’s roots consistently grow a…

Grad publication: Larissa Patterson

Whether it’s the stripes of a zebra, the spots of a leopard, or the dazzling diversity of colors and patterns displayed by tropical fish, pigment patterns are some of the most striking and memorable traits of an animal. A long-standing question for developmental biologists centers on how such remarkable diversity in color patterns is achieved. Fish, amphibians, and reptiles have many different pigment cell types found just under the skin, each producing a specific color. Different arrangements of these cells produce the remarkable diversity of patterns we see in nature. Zebrafish, found in most pet stores across the country, are known for their distinct pattern of alternating light and dark stripes. Recently, these horizontal stripes have attracted the attention of scientists seeking to understand how pigment cells are organized to produce complex patterns. Three different pigment cell types contribute to stripe formation. Black melanophores are found in dark stripes, yellow xantho…

Grad Publication: Marie Clifford

Hello all, a paper written by Marie Clifford is out in the Journal of Comparative Physiology A. Here's Marie:
      I recently published a review paper with my advisor Jeff Riffell about how insects process smells, or chemical signals, that they encounter in the environment. When I told this to one of my friends, they asked, rather pointedly actually, “Why should we care what insects think?!”

      Well, chemical signals mediate a heap of insect behaviors that are directly relevant to agriculture, medicine, and more. Smells help bees choose which flowers to visit, guide crop pests to their mates, and enable mosquitoes to find the source of their next blood meal, among many other things. Understanding how insects process olfactory information can help us understand how to encourage insects in beneficial behaviors (like pollinating our crops), as well as how to thwart them in their less appreciated efforts (like spreading malaria or making enough hungry baby insects that we l…

Grad Publications: David DeMar, Jonathan Calede, Daril Vilhena, Elisha Harris, Max Maliska, & Adam Huttenlocker -- An eruption of UW paleobiology!

Let this week be known as the week of UW paleobiology in the literature! It should be noted that these papers were either single author publications or the grad was the primary author.

      David DeMar described a new genus and species of salamander from the end of the Mesozoic in the Journal of Vertebrate Paleontology.
Dave: Paranecturus garbanii is a new genus and species of fossil salamander from the latest Cretaceous of Montana and is closely related to the modern day mudpuppy of the family Proteidae. P. garbanii is the oldest and only species of proteid salamander known to live prior to the Cretaceous-Paleogene boundary (~66 million years ago) thus implying that proteid salamanders survived the end Cretaceous mass extinction event.
Here is Dave's paper.

      Jonathan Calede's paper in the Journal of Mammalian Evolution looks at ontogenetic changes in a burrowing beaver and is based on his term paper for Greg Wilson's mammal evolution class.

      Jonathan: This…

Grad Publication: Daril Vilhena, Adam Huttenlocker, Brandon Peecook

What happens when one group of scientists accumulate a bunch of data, but don't quite know the best way to ask their questions, work in the same integrative department as a pioneering mathematical biologist with new methods, but no dataset?


      Over the last few years the Sidor lab has been criss-crossing southern continents (formerly a part of Gondwana 250,000,000 years ago) collecting vertebrate fossils from areas that had not been very well studied. These fossils, including several exciting new species, are from rocks on either side of the largest mass extinction event of all time, the end-Permian extinction event (~252.3 million years ago). Differences between the pre- and post extinction worlds were qualitatively obvious to us paleontologists and included a turnover of species, the rise of new clades, and changes in the biogeographic characteristics of assemblages.
      Last year Daril Vilhena, of the Bergstrom lab, and Chris Sidor began di…

Grad Publication: Adam Huttenlocker -- Bigger not always better in a post-extinction world?

Adam's paper: Huttenlocker, A. K., and J. Botha-Brink. 2013. Body size and growth patterns in the therocephalian Moschorhinus(Therapsida) before and after the end-Permian extinction in South Africa. Paleobiology. 39:253-277. doi:

        The K-Pg extinction, responsible for the catastrophic ecosystem collapse that blotted out the non-avian dinosaurs some 65 million years ago, is ostensibly the best-known extinction event in the entire history of Earth. But surprisingly few people are aware of an even greater event that disrupted links in communities on land and in the oceans during the Earth’s last major icehouse-hothouse transition about 252 million years ago: the end-Permian extinction. This event shared many characteristics with the K-Pg extinction, but with a much higher death toll, wiping-out nearly 90% of animal species. It is estimated that animal communities did not return to their former ecological diversity until some eight million years la…