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Full-Text Articles in Life Sciences
Fluctuating Viability Selection On Morphology Of Cliff Swallows Is Driven By Climate, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche
Fluctuating Viability Selection On Morphology Of Cliff Swallows Is Driven By Climate, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche
School of Natural Resources: Faculty Publications
The extent to which fluctuating selection can maintain evolutionary stasis in most populations remains an unresolved question in evolutionary biology. Climate has been hypothesized to drive reversals in the direction of selection among different time periods and may also be responsible for intense episodic selection caused by rare weather events. We measured viability selection associated with morphological traits in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, USA, over a 14-year period following a rare climatic event. We used mark-recapture to estimate the annual apparent survival of over 26 000 individuals whose wing, tail, tarsus, and bill had been …
Selective Breeding For High Endurance Running Increases Hindlimb Symmetry, Theodore Garland Jr., Patricia W. Freeman
Selective Breeding For High Endurance Running Increases Hindlimb Symmetry, Theodore Garland Jr., Patricia W. Freeman
School of Natural Resources: Faculty Publications
Comparative studies provide correlational evidence of morphological adaptations for high locomotor performance, such as the classical indicators of cursoriality in mammals, long limbs and high metatarsal/femur ratios. More recently, enlarged femoral condyles have been suggested as an adaptation for high endurance running in the genus Homo. Asymmetry of locomotor appendages should adversely affect locomotor abilities, but this has not been studied in a rigorous evolutionary context. We used experimental evolution to test for morphological adaptations associated with high voluntary wheel running in selectively bred lines of mice. Surprisingly, the classical indicators of cursoriality had not evolved in concert with …