Most Active Stories
Wed June 19, 2013
Dr. Michael Habib, University of Southern California – Novel Behavior and Evolution
In today’s Academic Minute, Dr. Michael Habib of the University of Southern California reveals why rarely-used behaviors can determine an animal’s evolutionary success.
Michael Habib is an assistant professor of cell and neurobiology at the Keck School of Medicine at the University of Southern California. As a paleontologist, he explores the relationships between animal structure and motion with a particular focus on collective behaviors such as swarming.
Dr. Michael Habib – Novel Behavior and Evolution
The application of control theory to the fossil record is set to fundamentally change how we view the evolutionary story of flight origins. Control theory is the body of theory that describes how much and how fast an animal or aircraft will turn, or how strongly it can stabilize itself, given shape, speed, and other basic variables.
Since the 1960s, a popular thought has been that animals evolved the ability to fly based on slow, steady changes or “improvements” in their common behaviors – for example, a gradual transition from climbing to steady gliding to partial flapping to full flapping. Now, scientists are starting to think that the origins of flight are actually driven by small but critical changes in control-based behaviors that are described as “high performance” – behaviors that an animal performs rarely but that can save its life. For example, the ability of gliding animal to control its flight path, especially during escape or pursuit, can critically alter chances of survival.
Our new application of control theory to fossil animals raises a fundamental issue in paleontology and evolutionary biology: behaviors animals carry out only rarely may sometimes have more of an effect on the history of life than common behaviors. Fossil animals such as Microraptor and Archaeopteryx have become central to this new model of flight evolution. For example, after applying principals of fluid dynamics and physics to well-known fossil specimens, my colleagues and I recently proposed that Microraptor’s unusual wing anatomy was probably an adaptation to turning. Our data also suggest that Archaeopteryx may not have been a particularly aerial animal, but instead was the Mesozoic version of a Parkour artist - using its wings to help leap, turn, stop and break falls.
Based on these new lines of research, our picture of bird origins is shifting towards a more complex scenario with multiple evolutionary paths and novel anatomies not seen in living birds. Most importantly, we are learning that the adaptions for flying as we see it today showed up in some unexpected and unintuitive ways.