Andrew Snyder-Beattie

Decoupling Global Drivers of Latitudinal Species Gradients with a View Towards Astrobiology

Species diversity is highest in the equatorial regions of our planet, declining as 
one moves to the poles. A plurality of ecological literature suggest one of two 
primary drivers behind this latitudinal gradient in species richness: amount of 
sunlight or amount of climatically consistent area. Gliese 581 is a star that 
provides an unique reframing for these two hypotheses. Rather than rotating like 
Earth, some planets of Gliese 581 are believed to be tidally locked, meaning that 
only one side of the planet faces the sun at all times. To investigate these two 
major ecological hypotheses and to examine hypothetical biospheres on other planets, 
classic Lotka-Volterra competition dynamics are placed on a spherical lattice to 
show how both area and sunlight can influence the global distribution of species. 
Preliminary results suggest that area has a stronger effect than solar inputs when 
species diversity is controlled by simple resource competition. We discuss the 
implications of this result for global species patterns both on Earth and tidally 
locked planets.

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Amanda Traud

High School and Prairie Dogs

The use of social network theory in evaluating animal social groups has gained 
traction in recent years. Despite the utility of social network analysis in 
describing attributes of social groups, it remains unclear how comparable this 
approach is to traditional behavioral observational studies. Using data on 
GunnisonŐs prairie dog (Cynomys gunnisoni) social interactions from three colonies 
we describe social networks of each colony. We then use social network analysis 
techniques to find groups of prairie dogs that are more connected to each other than 
to the rest of the colony, social network communities.  We compare these communities 
with social groups defined using traditional approaches and to behavioral traits on 
the prairie dogs within those communities. The social network communities identified 
were consistent with those identified by more traditional behavioral approaches. 
However, fine-grained social sub-structuring was revealed only with social network 
analysis. When comparing the social network communities to the prairie dog 
behavioral traits we found individuals within communities were more similar to each 
other. However, the traits that were similar among individuals within communities 
varied among colonies.