Dept. of Biology
Penn State University
208 Mueller Lab
University Park, PA 16802
Phone: 814- 863-1384
Email: jhm10 at psu.edu
Review and new perspective on why metabolic enzyme loci are so frequently targets of selection (online pub)
variation affecting the hypoxia inducible pathway affects insect
tracheal development, phyisology and ecology (online
evidence for a surface skimming insect in the Carboniferous (online
presents 14th Annual Strickland Memorial Lecture in Entomology at U. of
Alberta on Evol of Insect Flight
interests are primarily in the areas of
physiological ecology, functional genomics, evolutionary ecology,
In the most general terms, I am interested in how organisms work, and why they work that way. I investigate mechanistic details of physiology, along with ecological and historical reasons why particular physiological mechanisms have evolved.
Projects presently underway in my laboratory concentrate on using transcriptome and genome data from ecologically important species to inform physiological and mechanistic studies that further our understanding of how organisms operate and evolve in nature. Using that approach, we are presently examining the respiratory and energetic physiology in a butterfly (Melitaea cinxia) that is a model system for metapopulation biology. I have a new research collaboration and grant (with Liza Comita, Scott Mangan, and Claude dePamphilis) to do similar work with trees on the Forest Dynamics Plot in Panama.
My lab has maintained an interest in the way alternative splicing of a muscle gene, troponin-t, affects contractile performance. We have discovered recently that quantitative variation in the relative abundance of troponin-t splice forms is tightly related to the body weight of both insects and mammals. This provides a molecular indicator for how much a body "thinks" that it weighs. In collaboration with Ruud Schilder and colleagues at Hershey College of Medicine, we have examined physiological conditions that disrupt normal troponin-t splicing, including the effects of obesity. Dr. Schilder is now moving forward with this work on numerous fronts, with opportunities for ongoing collaborations with me and my students.
I have a long-standing interest in the way size and allometry (scaling) affect animal performance and energetics. We discovered that the mass scaling of force output by biological motors is a universal relationship that extends to human-designed motors as well. Using those results, I have worked with Adrian Bejan, an engineer and physicist at Duke university to generate a fundamental theory of animal locomotion. There are many potential ways to move forward with new studies combining empirical and theoretical approaches to gain a robust understanding of many aspects of organismal design and function.
Another longstanding and ongoing project involves the evolution of insect flight using stoneflies and other hemimetabolous insects.
photography and etc.
- link to a site where I to post some image galleries
Some present and past denizens of the lab: