Gila Monsters
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Team DeNardo

Jake Brashears

B.S. with Honors. Molecular Biosciences and Biotechnology. 2006. Arizona State University at Tempe.


Research Interests

I am interested in how complex behaviors and physiological processes could have evolved. Particularly, I am interested in the roles that hormones and external signals play in this evolution. My current research focuses on the physiological, hormonal, and evolutionary aspects of facultative thermogenesis in pythons in order to answer these types of questions.


Current Work

Many animals care for their young. Any care, no matter how limited, costs the parent some amount of energy. The reward, however, is an increase in the fitness of the young. The basic idea is that although an increase in parental care may cost the parent(s) quite a bit, as long as the young can breed more successfully than parents that don’t invest heavily, the behavior is evolutionarily viable. This type of selection can drive the evoluton of behaviors and physiological processes that intuitively seem too costly to be explained. Within squamates, pythons are a great example of animals that provide different levels of parental care. After they lay their eggs, they coil tightly around them and brood them until the eggs hatch. Some of them, particularly the Burmese python (Python molurus), even produce heat during brooding. An ectotherm becomes an endotherm!

This variation in brooding behavior allows me to ask questions about the mechanisms that regulate this behavior and how conserved these mechanisms are within pythons, eventually leading to a better understanding of how complex behavior can evolve. Specifically I am asking the following questions:

1. What is the behavior? I have done largely descriptive studies of brooding behavior in Burmese pythons and ball pythons (P. regius). These studies have incorporated the behavioral, metabolic, and thermal properties of the behavior.

2. Are their chemical cues that drive the behavior? Using mass spectrometry and a series of manipulative experiments, I am investigating whether the eggs provide a chemical cue that triggers female brooding behavior.

3. What are the hormonal reulators of the behavior? I am investigating the role of various steroids (progesterone, estradiol, corticosterone, testosterone), prolactin, and thyroxine in regulating different aspects of brooding behavior.



Brashears, J. A., and DeNardo, D. F. (2012) Do brooding pythons recognize their clutches? Investigating external cues for offspring recognition in the Children’s python, Antaresia childreni. Ethology, in press.

Poster Presentations

Correlations between muscle twitch, metabolic rate, and temperature in brooding Burmese pythons (Python molurus). January 2009. Society for Integrative and Comparative Biology Annual Meeting at Boston, MA.

Email jake.brashears@asu.edu

Curriculum Vitae

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