首页 | 本学科首页   官方微博 | 高级检索  
     


The validity of ecogeographical rules is context‐dependent: testing for Bergmann's and Allen's rules by latitude and elevation in a widespread Andean duck
Authors:Natalia Gutiérrez‐Pinto  Kevin G. McCracken  Luis Alza  Pablo Tubaro  Cecilia Kopuchian  Andrea Astie  Carlos Daniel Cadena
Affiliation:1. Laboratorio de Biología Evolutiva de Vertebrados, Departamento de Ciencias Biológicas, Universidad de los Andes, , 4976 Bogotá, Colombia;2. Department of Biology, 1301 Memorial Dr., University of Miami, , Coral Gables, FL, 33146 USA;3. Division of Marine Biology and Fisheries, 4600 Rickenbacker Causeway, Rosenstiel School of Marine and Atmospheric Sciences, , Miami, FL, 33149 USA;4. Institute of Arctic Biology, University of Alaska Museum, Department of Biology and Wildlife, , Fairbanks, AK, 99775 USA;5. Centro de Ornitología y Biodiversidad (CORBIDI), , Lima, Perú;6. División Ornitología, Museo Argentino de Ciencias Naturales ‘Bernardino Rivadavia’ (MACN‐CONICET), , Buenos Aires, Argentina;7. Centro de Ecología Aplicada del Litoral (CECOAL‐CONICET), , Corrientes, Argentina;8. Instituto Argentino de Investigaciones de las Zonas áridas (CCT Mendoza‐CONICET), , Mendoza, Argentina
Abstract:Consistent responses by various organisms to common environmental pressures represent strong evidence of natural selection driving geographical variation. According to Bergmann's and Allen's rules, animals from colder habitats are larger and have smaller limbs than those from warmer habitats to minimize heat loss. Although evidence supporting both rules in different organisms exists, most studies have considered only elevational or latitudinal temperature gradients. We tested for the effects of temperature associated with both elevation and latitude on body and appendage size of torrent ducks (Merganetta armata), a widespread species in Andean rivers. We found a negative relationship between body size and temperature across latitude consistent with Bergmann's rule, whereas there was a positive relationship between these variables along replicate elevational gradients at different latitudes. Limb‐size variation did not support Allen's rule along latitude, nor along elevation. High‐elevation ducks were smaller and had longer wings than those inhabiting lower elevations within a river. We hypothesize that temperature is likely a major selective pressure acting on morphology across latitudes, although hypoxia or air density may be more important along elevational gradients. We conclude that the effect of temperature on morphology, and hence the likelihood of documenting ecogeographical ‘rules’, depends on the environmental context in which temperature variation is examined. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 850–862.
Keywords:adaptation  Andes  biogeography  ecological gradients  Merganetta armata  temperature
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号