Tuesday, November 5, 2013

SVP Summary Part 1: Dinosaurs are Surprisingly Relevant

We know, we know, there was no blog post last week. We're sorry. We were doing a science. We'll make up for it by posting too much this week instead!

Amy is still trying to pull together her thoughts from GSA (the beer there was free), but Meaghan has decided that instead of creating a cohesive summary she's going to vomit some grey matter on the page and let all y'all just deal with it. Today we're going to talk about Meaghan's favorite non-poster presentation which was, surprisingly, a dinosaur talk!

Influence of Multi-Niche Ontogeny on Differential Survivorship Across the K-PG Boundary 
 by Fowler, Freedman-Fowler, Scannella and Horner
Translation: Baby dinosaurs probably ate different things than adult dinosaurs. Teenage dinosaurs maybe ate different stuff too. This makes a chain of animals that eat different things and maybe live in different places (aka, multiple niches). Mammals don't do this, except for my family where the kids are such picky eaters that you grow up eating only balogna and cucumber until you graduate high school. But typically, baby mammals drink milk until they eat whatever their mother eats.

So how can this affect extinction? Well, theoretically, if you cut out any one ecosystem from the chain of dinosaur niches, you cause the whole species to go extinct! They did some modelling to test whether selectively removing niches put dinosaurs at extra risk (or: they made a computer randomly cross out some dots) and found that yep yep, it sure did. Their conclusion was that while having multiple niches might be useful during times of environmental stability (re: when asteroids aren't raining down on you from the sky), they are less beneficial during times of change.

They didn't really discuss the ramifications of this, but they are very important. Dinosaurs = multi-niche = dead is a pretty nasty equation for a lot of our reptiles and our amphibians.

Shown above are the larval and adult forms of the Giant Pacific Salamander. Now this salamander, to its credit, has a wierd thing going on called paedomorphosis that might help shield it from some of the effects of an ecosystem change that selects against organisms that have multiple niches. These guys are the definition of baby-faced, really: they can stay in the water and breed as a larval-shaped adult. So if being on land is maybe a shitty life choice, it's no biggy cuz they are capable of staying in the water and breeding there. Many amphibians  are not quite so lucky and are unable to make the switch. However, the whys and wherefores of this switch are not well understood. Maybe they only make the switch when the full moon hangs low in the constellation of Leo, or something. It needs Moar Research.

But an organism doesn't have to have a larval form in order to occupy multiple niches throughout its life. Shown above are a baby and an adult komodo dragon. While the heavy adults are terrestrial and stalk open land looking menacing and killing animals with their venom*, juveniles are arboreal and live in forests. Imagine what would happen if there were no trees nearby: boom, no more successful baby dragon stages.

So basically, this dinosaur talk was very interesting and had a lot of great applications to modern biological systems. Yay!


*So peeps used to think that Komodos didn't have venom and just killed their prey with super gross bacteria-ridden mouths. That's apparently not the the case. However, it totally destroys a really great joke that I had about them stalking the open lands killing animals with their nasty ass breath (with a following joke in parenthesis like this explaining that you could put the hypen anywhere in those three words and be correct). I was bummed about the world losing that joke. I will mourn it. It was a good one. Stupid Komodo dragons.