Monday, April 13, 2015

Nature vs. Nurture - 7th graders visit CSU

Today I hosted 22 7th graders from Mapleton Expeditionary School of the Arts (MESA) in Thornton, CO (over an hour from here).  Their teacher, Ashley Luythe, asked those of us in the biology department if we could help her teach a unit on heredity and genetics.  I thought the guppy work was perfect since much of our work uses common-garden style experiments to test whether phenotypes are driven by genetic or environmental influences.  So I helped them arrange a trip up to CSU to learn about what we do.

We started the day by talking about genotypes and phenotypes, environmental and genetic influences (with an example using handedness), and why we use guppies to address our questions.  Then we had a lot of fun modeling the effects of color on predation risk using skittles as our prey.  We put them on colored backgroundsto see how many of which colors were "captured".  Once the students generated histograms of their data, we found out that the skittles that matched the background were "captured" less often!

Preparing to "capture" skittles

Making histograms

Discussing the role of color in survival

We also looked at 4 guppies and compared their color.  Two guppies were low predation brothers that were raised in two environments, and the other two were high predation brothers raised in two environments.  By knowing the genetic background as well as the rearing history, we determined that color brightness in guppies was primarily determined by environmental changes!  The students also had a chance to tour our guppy rearing facility at the end of their visit.

Examining guppy coloration

Comparing guppies raised in different environments

Discussing genetic and environmental influences

After talking about guppies, they also heard from Molly Womack, who talked about her research on earless toads!  She brought cleared and stained toads, a fish embedded for histological sectioning, and live eared and earless toads for everyone to see!  She also gave the students a chance to ask those burning questions about her life as a graduate student.  They had great questions!

Examining two species of toads

This looks like a fishing story..."it was THIS big!"

A cleared and stained toad

Thanks to several graduate and undergraduate students for helping with this activity: Rachel Bockrath, Dale Broder, Francis Commercon, Travis Klee, Mitchell Leroy, and Molly Womack!  Hopefully their trip to CSU inspired the 7th graders to learn more about genetics and heredity.

Wednesday, April 8, 2015

ICB manuscript accepted!

Look for my manuscript in Integrative and Comparative Biology soon (Update 5/15/15: it's out now here!  This is a compliment to what I presented at SICB in West Palm Beach at the symposium "New Insights into Suction Feeding Biomechanics and Evolution" organized by my PhD advisor, Tim Higham, and his PhD advisor, Peter Wainwright.

What are our predictions of how an "integration space"
explains fish diversity?  Read the paper to find out!

In summary, we were interested in increasing awareness and providing methods and a context for thinking about complex behaviors and how multiple functional systems can be coordinated and integrated when they work together to accomplish a common task.  We use prey capture in fishes as the common task involving both locomotor and feeding functional systems as an example of this idea because of the extensive background on each system in this group.  We aim to do 4 things in this paper: 1) discuss complexity and integration and what they mean to biomechanics, 2) discuss the importance of integration for understanding patterns of diversity (here we hypothesize the integration space above), 3) provide empirical demonstrations of integration using a meta-analysis of ram and gape from several species found in the literature as well as a multivariate re-analysis of previously published sculpin data, and 4) discuss how this approach adds novel insights into organism function and diversity as well as outline future questions related to these ideas. We hope this work can be used to drive the future of study on complex functional behaviors, and that future work on fish feeding acknowledges the potentially significant role that other systems, such as locomotion, can play in diversification patterns.

For fun, here are some videos of black crappie (Pomoxis nigromaculatus) capturing two prey types.  Notice the very interesting locomotor strategy of crappie when capturing evasive fish prey - a roll behavior, coupled with a slow stalk and quick burst of acceleration.

This is not observed when capturing other types of prey such as frozen bloodworms.

Interesting examples of the importance of locomotion during prey capture!