Jim Marden


picture of me 


Dept. of Biology
Assoc. Dir. Huck Institutes of the Life Sciences

Penn State University
208 Mueller Lab
University Park, PA 16802

Phone: 814- 863-1384  
    Fax: 814-865-9131   
    Email: jhm10 at psu.edu

Some highlights:

Origin and diversification of insect wings, as revealed by RNAi and transcriptomics in a hemipteran insect (online pub)

Review and new perspective on why metabolic enzyme loci are so frequently targets of selection (online pub)

Genetic variation affecting the hypoxia inducible factor pathway affects insect tracheal development, phyisology and ecology (online pub)

Fossil evidence for a surface skimming insect in the Carboniferous (online pub).

14th Annual Strickland Memorial Lecture in Entomology at U. of Alberta on Evol of Insect Flight

Schilder (co-authors Kimball, Marden & Jefferson) wins Best Poster award at Amer Physiol Soc meeting

Plenary lecture at French Workshop on Robotics, CNRS  Institute

Schilder wins Scholander Award from American Physiological Society for work from his PhD at PSU; publishes invited commentary in J. Diabetes Sci. Tech.

1999-2015: Seven papers in four different sections of PNAS   (Physiology, Evolution, Genetics, Engineering)

Research Interests:

My research interests are highly integrative, spanning physiological ecology, functional genomics, evolutionary ecology, biomechanics, and behavior.  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 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.  In another collaborative project (with Liza Comita, Scott Mangan, and Claude dePamphilis, working with the
Forest Dynamics Plot in Panama) we are examining how reductions in local population size affect allelic diversity of pathogen resistance genes of tropical rainforest trees, and how that affects plant-pathogen interactions.

My lab has a long-standing interest in the way alternative splicing of a muscle gene, troponin-t, affects contractile performance. We discovered 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 Dr. Ruud Schilder and colleagues at Hershey College of Medicine, we examined physiological conditions that disrupt normal troponin-t splicing, including obesity. Dr. Schilder is 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 various aspects of organismal design and function.

Another longstanding and ongoing project involves the evolution of insect flight using stoneflies and other hemimetabolous insects.  I am collaborating with Dr. Aleks Popadic and his students at Wayne State Univesity; we are combining RNAi and transcriptomic approaches to examine the origin and diversification of insect wings.

Courses that I teach:


Quick-time movies from our studies of the evolutionary origins of insect flight

Nature photography and etc. - link to a site where I to post some image galleries

       Some present and past denizens of the lab:

MarkPeterson        Emily_H        Erica_S      
        Dr. Mark Peterson                           Dr. Emily Hornett                            Erica Shearer

heat mug shot        Ruud's mug      risti mug       annyC                                   
          Dr. Chris Wheat                              Dr. Ruud Schilder                  Dr. Kristi Montooth                 Dan Cassarella

ike's mug         oward Fescemyer      hris vera     elissa  
          Dr. Michael Thomas              Dr. Howard Fescemyer                         Cris Vera                           Melissa Kramer

weta         rigid     arry     ason
      Dr. Sweta Girgenrath           Dr. Brigid O'Donnell               Barry Rowan                      Jason Cobb              

ohnF     arah   Reed   Tahira  
               John Frisch                                  Sarah Wherry                           W. Reed Doerfler               Tahira West

          Julianne Pekny                             Daniel Matasic