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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.

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Related in: MedlinePlus

Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Paleocene and Eocene.Taxa that went locally extinct in these regions in the Modern are gray-shaded, along with the internal branches removed from the tree as a result of these absences. Internal nodes are scaled to first appearance of each family in the fossil record. Numbers and bars along the right edge demark family groupings within orders, following Bieler & Mikkelsen [44], except placement of Thyasiridae outside of (Veneroida + Lucinidae), following Taylor et al. [50]. 1. Solemyoida, 2. Nuculoida, 3. Nuculanoida, 4. Arcoida, 5. Mytiloida, 6. Pterioida, 7. Limoida, 8. Pectinoida, 9. Trigonioida, 10. Carditoida, 11. Anomalodesmata, 12. Veneroida, 13. Myoida.
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pone-0015362-g001: Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Paleocene and Eocene.Taxa that went locally extinct in these regions in the Modern are gray-shaded, along with the internal branches removed from the tree as a result of these absences. Internal nodes are scaled to first appearance of each family in the fossil record. Numbers and bars along the right edge demark family groupings within orders, following Bieler & Mikkelsen [44], except placement of Thyasiridae outside of (Veneroida + Lucinidae), following Taylor et al. [50]. 1. Solemyoida, 2. Nuculoida, 3. Nuculanoida, 4. Arcoida, 5. Mytiloida, 6. Pterioida, 7. Limoida, 8. Pectinoida, 9. Trigonioida, 10. Carditoida, 11. Anomalodesmata, 12. Veneroida, 13. Myoida.

Mentions: In the early Cenozoic, the Arctic and Antarctic had 35 and 40 recorded bivalve families, respectively, the difference likely reflecting the poorer Arctic fossil record, with twenty-seven families shared by the two regions during the Paleocene/Eocene (Table S1). Thus the faunas began the Cenozoic with similar compositions, but since then 20 of the 40 Antarctic families, but only 12 Arctic families, have gone extinct regionally (Fig. 1a,b).


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 Paleocene and Eocene.Taxa that went locally extinct in these regions in the Modern are gray-shaded, along with the internal branches removed from the tree as a result of these absences. Internal nodes are scaled to first appearance of each family in the fossil record. Numbers and bars along the right edge demark family groupings within orders, following Bieler & Mikkelsen [44], except placement of Thyasiridae outside of (Veneroida + Lucinidae), following Taylor et al. [50]. 1. Solemyoida, 2. Nuculoida, 3. Nuculanoida, 4. Arcoida, 5. Mytiloida, 6. Pterioida, 7. Limoida, 8. Pectinoida, 9. Trigonioida, 10. Carditoida, 11. Anomalodesmata, 12. Veneroida, 13. Myoida.
© Copyright Policy
Related In: Results  -  Collection

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

pone-0015362-g001: Subset of bivalve phylogenetic tree present in A. Antarctica and B. the Arctic Circle in the Paleocene and Eocene.Taxa that went locally extinct in these regions in the Modern are gray-shaded, along with the internal branches removed from the tree as a result of these absences. Internal nodes are scaled to first appearance of each family in the fossil record. Numbers and bars along the right edge demark family groupings within orders, following Bieler & Mikkelsen [44], except placement of Thyasiridae outside of (Veneroida + Lucinidae), following Taylor et al. [50]. 1. Solemyoida, 2. Nuculoida, 3. Nuculanoida, 4. Arcoida, 5. Mytiloida, 6. Pterioida, 7. Limoida, 8. Pectinoida, 9. Trigonioida, 10. Carditoida, 11. Anomalodesmata, 12. Veneroida, 13. Myoida.
Mentions: In the early Cenozoic, the Arctic and Antarctic had 35 and 40 recorded bivalve families, respectively, the difference likely reflecting the poorer Arctic fossil record, with twenty-seven families shared by the two regions during the Paleocene/Eocene (Table S1). Thus the faunas began the Cenozoic with similar compositions, but since then 20 of the 40 Antarctic families, but only 12 Arctic families, have gone extinct regionally (Fig. 1a,b).

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
Related in: MedlinePlus