The Dynamics of Phenotypic Change and the Shrinking Sheep of St. Kilda

• DOI: 10.1126/science.1173668
• Publication Date: 2009-07-07T22:42:40Z
• Authors: Arpat Ozgul; Shripad Tuljapurkar; Tim G. Benton; Josephine M. Pemb...; Tim H. Clutton-Brock; Tim Coulson
• Keywords: Environmental change; Evolutionary Dynamics

Environmental change, including climate can cause rapid phenotypic change via both ecological and evolutionary processes. Because dynamics are intimately linked, a major challenge is to identify their relative roles. We exactly decomposed the in mean body weight free-living population of Soay sheep into all processes that contribute change. Ecological most, with selection--the underpinning adaptive evolution--explaining little observed trend. Our results enable us explain why selection has so effect even though heritable, environmental caused decline size sheep.