Evolutionary diversification in the marine realm: a global case study with marine mammals

Frontiers of Biogeography

article

Ben G. Holt¹  Felix G. Marx³  Susanne A. Fritz⁵  Jean-Philippe Lessard⁷  Carsten Rahbek¹ 

[1] Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen;Marine Biological Association of the UK, The Laboratory;Museum of New Zealand Te Papa Tongarewa;Department of Geology, University of Otago;Senckenberg Biodiversity and Climate Research Centre;Institute of Ecology, Evolution and Diversity, Goethe University;Department of Biology, Concordia University

关键词: barriers;    biogeography;    dispersal;    ecology;    evolution;    oceanic;    phylo-betadiversity;    phylogenetic diversity;   

DOI  :  10.21425/F5FBG45184

学科分类：社会科学、人文和艺术（综合）

来源: International Biogeography Society

【 摘 要 】

Speciation is thought to be predominantly driven by the geographical separation of populations of the ancestral species. Yet, in the marine realm, there is substantial biological diversity despite a lack of pronounced geographical barriers. Here, we investigate this paradox by considering the biogeography of marine mammals: cetaceans (whales and dolphins) and pinnipeds (seals and sea lions). We test for associations between past evolutionary diversification and current geographical distributions, after accounting for the potential effects of current environmental conditions. In general, cetacean lineages are widely dispersed and show few signs of geographically driven speciation, albeit with some notable exceptions. Pinnipeds, by contrast, show a more mixed pattern, with true seals (phocids) tending to be dispersed, whereas eared seals (otariids) are more geographically clustered. Both cetaceans and pinnipeds show strong evidence for environmental clustering of their phylogenetic lineages in relation to factors such as sea temperature, the extent of sea ice, and nitrate concentrations. Overall, current marine mammal biogeography is not indicative of geographical speciation mechanisms, with environmental factors being more important determinants of current species distributions. However, geographical isolation appears to have played a role in some important taxa, with evidence from the fossil record showing good support for these cases.

【 授权许可】

CC BY