Karen E. Sears earned her Ph.D. in Evolutionary Biology in 2003: her advisor was John Flynn. She joined the faculty of the University of Illinois at Urbana-Champaign in late 2007, and is now a Professor of Ecology & Evolutionary Biology at UCLA. She currently serves as the department chair. Karen actively engages in community outreach and was a featured scientist in the PBS/HHMI documentary Your Inner Fish.
Karen's main interest is to harness the power of evolutionary and developmental biology to explain and predict the course of mammalian evolution. Her lab's primary research goals are to determine how developmental variation interacts with environmental factors within a species to produce congenital malformations in humans, and among species to generate new evolutionary adaptations in mammals. They are studying the evolution and devopment of forms, sensory adaptations ahd human health.
Sears has identified cellular and molecular processes that drive the unique development of marsupial (e.g., kangaroos, opossums) limbs and generated a possible hypothesis for the abundance of placentals (e.g., humans, dogs, horses) relative to marsupials in today’s world. She has also identified genetic and developmental drivers of digit reduction (i.e., reduction in the number of size of the fingers and toes) in mammalian species such as horses, pigs and deer. Her results suggest that mammals can reduce their digits through many processes and thereby provide a plausible explanation for the frequent evolutionary reduction of mammalian digits.
Although her primary focus has been on the limb, Karen strives to continually reinvent her research program by incorporating new species, techniques, and organ systems. Sears has been awarded a "Dimensions of Biodiversity" grant from NSF that funds research on discovering genomic and developmental mechanisms that underlie sensory innovations critical to adaptive diversification. All animals must sense their environment to find food, avoid threats, and find partners. This research illuminates the main biological forces in the genome, during development, and in anatomical structures that contribute to mammals’ success in adapting to their ever-changing environment.