TY - JOUR

T1 - Ecological, morphological and genetic divergence of sympatric North Atlantic killer whale populations

AU - Foote, Andrew D

AU - Newton, Jason

AU - Piertney, Stuart B

AU - Willerslev, Eske

AU - Gilbert, M Thomas P

N1 - Keywords: Animals; Bayes Theorem; DNA, Mitochondrial; Ecosystem; Evolution, Molecular; Genetics, Population; Likelihood Functions; Nitrogen Isotopes; Phylogeny; Sequence Analysis, DNA; Tooth Wear; Whale, Killer

PY - 2009

Y1 - 2009

N2 - Ecological divergence has a central role in speciation and is therefore an important source of biodiversity. Studying the micro-evolutionary processes of ecological diversification at its early stages provides an opportunity for investigating the causative mechanisms and ecological conditions promoting divergence. Here we use morphological traits, nitrogen stable isotope ratios and tooth wear to characterize two disparate types of North Atlantic killer whale. We find a highly specialist type, which reaches up to 8.5 m in length and a generalist type which reaches up to 6.6 m in length. There is a single fixed genetic difference in the mtDNA control region between these types, indicating integrity of groupings and a shallow divergence. Phylogenetic analysis indicates this divergence is independent of similar ecological divergences in the Pacific and Antarctic. Niche-width in the generalist type is more strongly influenced by between-individual variation rather than within-individual variation in the composition of the diet. This first step to divergent specialization on different ecological resources provides a rare example of the ecological conditions at the early stages of adaptive radiation.

AB - Ecological divergence has a central role in speciation and is therefore an important source of biodiversity. Studying the micro-evolutionary processes of ecological diversification at its early stages provides an opportunity for investigating the causative mechanisms and ecological conditions promoting divergence. Here we use morphological traits, nitrogen stable isotope ratios and tooth wear to characterize two disparate types of North Atlantic killer whale. We find a highly specialist type, which reaches up to 8.5 m in length and a generalist type which reaches up to 6.6 m in length. There is a single fixed genetic difference in the mtDNA control region between these types, indicating integrity of groupings and a shallow divergence. Phylogenetic analysis indicates this divergence is independent of similar ecological divergences in the Pacific and Antarctic. Niche-width in the generalist type is more strongly influenced by between-individual variation rather than within-individual variation in the composition of the diet. This first step to divergent specialization on different ecological resources provides a rare example of the ecological conditions at the early stages of adaptive radiation.

M3 - Journal article

C2 - 20050301

VL - 18

SP - 5207

EP - 5217

JO - Molecular Ecology

JF - Molecular Ecology

SN - 0962-1083

IS - 24

ER -