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Differential extinction and the contrasting structure of polar marine faunas.

Krug AZ, Jablonski D, Roy K, Beu AG - PLoS ONE (2010)

Bottom Line: A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages.Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats.These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the "retrograde" hypothesis of Antarctic faunal evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Geophysical Sciences, University of Chicago, Chicago, Illinois, United States of America. akrug@uchicago.edu

ABSTRACT

Background: The low taxonomic diversity of polar marine faunas today reflects both the failure of clades to colonize or diversify in high latitudes and regional extinctions of once-present clades. However, simple models of polar evolution are made difficult by the strikingly different faunal compositions and community structures of the two poles.

Methodology/principal findings: A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages. Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats.

Conclusions/significance: These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the "retrograde" hypothesis of Antarctic faunal evolution.

Show MeSH
Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Modern.Note that while most of the extinctions in Antarctica are permanent, most of the evolutionary history in the Arctic tree is retained owing to the persistence/introduction of sister families of those that went extinct in this region. Family groupings within orders marked as in figure 1.
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pone-0015362-g002: Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Modern.Note that while most of the extinctions in Antarctica are permanent, most of the evolutionary history in the Arctic tree is retained owing to the persistence/introduction of sister families of those that went extinct in this region. Family groupings within orders marked as in figure 1.

Mentions: Extinction in Antarctica is strongly (D = .097) and significantly (Standardized Effect Size MPD  = −1.8, p = .03; SESMNTD  = −2.5, p = .003;) clustered phylogenetically, with extinctions concentrated in the orders Myoida, Veneroida and Pterioida (see Figure S1, Table S2 for ordinal assignments), and the family-level phylogenetic history of the Antarctic fauna was reduced by at least 27–38%, depending on the metric (see Materials and Methods). The loss of the myoids and most veneroids is particularly striking because their extinction eliminates the most derived portions of the evolutionary tree, with the remaining families largely representing more basal lineages (Fig. 2a).


Differential extinction and the contrasting structure of polar marine faunas.

Krug AZ, Jablonski D, Roy K, Beu AG - PLoS ONE (2010)

Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Modern.Note that while most of the extinctions in Antarctica are permanent, most of the evolutionary history in the Arctic tree is retained owing to the persistence/introduction of sister families of those that went extinct in this region. Family groupings within orders marked as in figure 1.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3008738&req=5

pone-0015362-g002: Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Modern.Note that while most of the extinctions in Antarctica are permanent, most of the evolutionary history in the Arctic tree is retained owing to the persistence/introduction of sister families of those that went extinct in this region. Family groupings within orders marked as in figure 1.
Mentions: Extinction in Antarctica is strongly (D = .097) and significantly (Standardized Effect Size MPD  = −1.8, p = .03; SESMNTD  = −2.5, p = .003;) clustered phylogenetically, with extinctions concentrated in the orders Myoida, Veneroida and Pterioida (see Figure S1, Table S2 for ordinal assignments), and the family-level phylogenetic history of the Antarctic fauna was reduced by at least 27–38%, depending on the metric (see Materials and Methods). The loss of the myoids and most veneroids is particularly striking because their extinction eliminates the most derived portions of the evolutionary tree, with the remaining families largely representing more basal lineages (Fig. 2a).

Bottom Line: A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages.Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats.These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the "retrograde" hypothesis of Antarctic faunal evolution.

View Article: PubMed Central - PubMed

Affiliation: Department of Geophysical Sciences, University of Chicago, Chicago, Illinois, United States of America. akrug@uchicago.edu

ABSTRACT

Background: The low taxonomic diversity of polar marine faunas today reflects both the failure of clades to colonize or diversify in high latitudes and regional extinctions of once-present clades. However, simple models of polar evolution are made difficult by the strikingly different faunal compositions and community structures of the two poles.

Methodology/principal findings: A comparison of early Cenozoic Arctic and Antarctic bivalve faunas with modern ones, within the framework of a molecular phylogeny, shows that while Arctic losses were randomly distributed across the tree, Antarctic losses were significantly concentrated in more derived families, resulting in communities dominated by basal lineages. Potential mechanisms for the phylogenetic structure to Antarctic extinctions include continental isolation, changes in primary productivity leading to turnover of both predators and prey, and the effect of glaciation on shelf habitats.

Conclusions/significance: These results show that phylogenetic consequences of past extinctions can vary substantially among regions and thus shape regional faunal structures, even when due to similar drivers, here global cooling, and provide the first phylogenetic support for the "retrograde" hypothesis of Antarctic faunal evolution.

Show MeSH