Bats and Rats: Evolutionary Implications and Hindlimb Development

Tara Hobbs, and Dr. Rick Adams, Department of Biological Sciences, University of Northern Colorado, 501 20th Street, Greeley CO 80639

Forelimb development in bats is well-studied, but little is known about hindlimb development, even though it helps support the flight membrane. Our hypothesis was that the growth and development of the hindlimb in bats would differ from terrestrial mammals (mice) due to the adaptive demands of flight. Greatest length measurements (mm) were taken of the femur, tibia, and skull. For comparative measures with an ancestral terrestrial mammal, data on mouse femur, tibia, and skull lengths were gathered from the literature. Regression analysis for growth of the femur and tibia in mice compared to skull length showed a slope of 0.75 (R2 = 0.97) and 0.74 (R2 = 0.99) respectively. Carollia perspicillata showed a lower slope for femur (0.49, R2 = 0.87) and tibia (0.49, R2 = 0.88) growth indicating that the hindlimb grows at a slower rate relative to the skull in bats than in mice. Regressing tibia and femur lengths against each other showed that the growth rate (slope = 0.95, R2 = 0.94) of the femur to the tibia had negative allometry with the tibia outpacing the femur, whereas C. perspicillata showed a positive allometric growth rate (slope = 1.1, R2 = 0.98) indicating that femur growth outpaced tibia growth in bats. These data indicate that the ontogeny of the hindlimb in bats has shifted away from a more ancestral terrestrial mammal due to selective pressures around the evolution of flight. This research is significant because it is novel and can now aid in further studies about hindlimb development and ontogeny in bats where literature was lacking before.

Additional Abstract Information

Presenter: Tara Hobbs

Institution: University of Northern Colorado

Type: Poster

Subject: Biology

Status: Approved

Time and Location

Session: Poster 2
Date/Time: Mon 3:00pm-4:00pm
Session Number: 2671