Behavioural Ecology of Cetaceans

Boran, James; Evans, Peter G. H.; Rosen, Martin J.

doi:10.1007/978-1-4615-0529-7_5

Cited by 3 publications

(1 citation statement)

References 87 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Although the timing of the invasions into the riverine habitat by various river dolphin lineages is uncertain ( Hamilton et al 2001 ), this realm was probably not affected by oceanic restructuring either. Interestingly, extant porpoises, which occupy habitats likely to have been affected by oceanic restructuring ( Boran et al 2002 ), also show a recent relatively rapid diversification. The diversification pattern of cetaceans is thus consistent with the hypothesis that abiotic factors were important in their evolution.…”

Section: R Esults and Discussionmentioning

confidence: 99%

Radiation of Extant Cetaceans Driven by Restructuring of the Oceans

et al. 2009

View full text Add to dashboard Cite

The remarkable fossil record of whales and dolphins (Cetacea) has made them an exemplar of macroevolution. Although their overall adaptive transition from terrestrial to fully aquatic organisms is well known, this is not true for the radiation of modern whales. Here, we explore the diversification of extant cetaceans by constructing a robust molecular phylogeny that includes 87 of 89 extant species. The phylogeny and divergence times are derived from nuclear and mitochondrial markers, calibrated with fossils. We find that the toothed whales are monophyletic, suggesting that echolocation evolved only once early in that lineage some 36–34 Ma. The rorqual family (Balaenopteridae) is restored with the exclusion of the gray whale, suggesting that gulp feeding evolved 18–16 Ma. Delphinida, comprising all living dolphins and porpoises other than the Ganges/Indus dolphins, originated about 26 Ma; it contains the taxonomically rich delphinids, which began diversifying less than 11 Ma. We tested 2 hypothesized drivers of the extant cetacean radiation by assessing the tempo of lineage accumulation through time. We find no support for a rapid burst of speciation early in the history of extant whales, contrasting with expectations of an adaptive radiation model. However, we do find support for increased diversification rates during periods of pronounced physical restructuring of the oceans. The results imply that paleogeographic and paleoceanographic changes, such as closure of major seaways, have influenced the dynamics of radiation in extant cetaceans.

show abstract

Section: R Esults and Discussionmentioning

confidence: 99%