Research

Evolution and Biomechanics in Arthropods

1.  Characterizing and understanding mechanical phenomena in arthropods

I have worked on a variety of animals and systems, with the common goal of answering questions about their unique mechanical abilities. While this is a subfield of biology, it is one that works at the interfaces between biology and physics, engineering, and robotics. At its best, this work involves collaboration between biologists and workers trained in the latter fields.

Most of my work to date has been on spiders, including work on their webs, silks, and running abilities. Some of the work on running ability has led to comparisons with cockroaches, crabs, and beetles. They have some interesting commonalities, and have led  to the application of spider and cockroach leg features to improve robot legs. My postdoctoral project is on the mechanics of trap-jaw usage in ants, including the speed, force, and energy storage of these ants’ jaws and heads, as well as the ecological and evolutionary correlates of trap-jaw usage. 

Spider running on mesh surface (screen door material,
Home Depot, Richmond CA).

2.  Integrating biomechanics and evolution

While it is very satisfying to characterize how something works, all of biology has a history, and a full understanding of any aspect of biology requires historical context. Evolution has a variety of effects on the mechanics of animals: it can optimize, streamline, constrain, diversify, co-opt, and prevent transmission of features through time. This can occur through deterministic and stochastic (probabilistic) processes. It is not enough to assume that a feature that seems to work is "adaptive," or optimal, or even helpful.  Rather, these ideas are hypotheses that need to be rigorously tested in the context of the best "evolutionary tree" we can generate.

Variation in jaw morphology in trap-jaw ants.

To generate these trees, biologists use phylogenetic analyses to decipher the patterns of descent of arthropod lineages. These phylogenies can then be used to trace and test hypotheses of the processes of evolution for mechanical features. My phylogenetic work has been on spiders, using primarily molecular (DNA) data, but also using morphological and cytogenetic evidence, to decipher the branching patterns in the spider "tree of life." I have focused on the same groups I have studied biomechanically, and their relatives.  As a result, my taxonomic expertise is in spiders of a large group called the "RTA clade" focusing on the families Agelenidae, Amaurobiidae, and Dictynidae.

Suarez Laboratory
Beckman Institute of Advanced Science and Technology
Department of Entomology
School of Integrative Biology
University of Illinois