Comparative support for the niche variation hypothesis that more generalized populations also are more heterogeneous

• DOI: 10.1073/pnas.0703743104
• Publication Date: 2007-05-31T00:49:12Z
• Authors: Daniel I. Bolnick; Richard Svanbäck; Márcio S. Araújo; Lennart Persson
• Keywords: Anolis; Niche segregation; Variation (astronomy); Niche differentiation

There is extensive evidence that some species of ecological generalists, which use a wide diversity resources, are in fact heterogeneous collections relatively specialized individuals. This within-population variation, or "individual specialization," key requirement for frequency-dependent interactions may drive variety types evolutionary diversification and influence the population dynamics species. Consequently, it important to understand when individual specialization likely be strong weak. The niche variation hypothesis (NVH) suggests populations tend become more generalized they released from interspecific competition. expansion was proposed arise via increased among individuals rather than breadth. we expect generalists exhibit stronger specialization, but this correlation has been repeatedly rejected by empiricists. drawback with previous empirical tests NVH morphological as proxy ignoring role behavior complex phenotype-function relationships. Here, used diet data directly estimate Consistent NVH, show also variation. trend quite general, appearing all five case studies examined: three-spine stickleback, Eurasian perch, Anolis lizards, intertidal gastropods, community neotropical frogs. Our results suggest generalist ecologically variable. Whether translates into greater genetic evolvability, stability remains determined.