The soft explosive model of placental mammal evolution
Abstract Background Recent molecular dating estimates for placental mammals echo fossil inferences for an explosive interordinal diversification, but typically place this event some 10–20 million years earlier than the Paleocene fossils, among apparently more “primitive” mammal faunas. Results Howev...
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| Format: | Article |
| Language: | English |
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BMC
2018-07-01
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| Series: | BMC Evolutionary Biology |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s12862-018-1218-x |
| _version_ | 1831574013404512256 |
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| author | Matthew J. Phillips Carmelo Fruciano |
| author_facet | Matthew J. Phillips Carmelo Fruciano |
| author_sort | Matthew J. Phillips |
| collection | DOAJ |
| description | Abstract Background Recent molecular dating estimates for placental mammals echo fossil inferences for an explosive interordinal diversification, but typically place this event some 10–20 million years earlier than the Paleocene fossils, among apparently more “primitive” mammal faunas. Results However, current models of molecular evolution do not adequately account for parallel rate changes, and result in dramatic divergence underestimates for large, long-lived mammals such as whales and hominids. Calibrating among these taxa shifts the rate model errors deeper in the tree, inflating interordinal divergence estimates. We employ simulations based on empirical rate variation, which show that this “error-shift inflation” can explain previous molecular dating overestimates relative to fossil inferences. Molecular dating accuracy is substantially improved in the simulations by focusing on calibrations for taxa that retain plesiomorphic life-history characteristics. Applying this strategy to the empirical data favours the soft explosive model of placental evolution, in line with traditional palaeontological interpretations – a few Cretaceous placental lineages give rise to a rapid interordinal diversification following the 66 Ma Cretaceous-Paleogene boundary mass extinction. Conclusions Our soft explosive model for the diversification of placental mammals brings into agreement previously incongruous molecular, fossil, and ancestral life history estimates, and closely aligns with a growing consensus for a similar model for bird evolution. We show that recent criticism of the soft explosive model relies on ignoring both experimental controls and statistical confidence, as well as misrepresentation, and inconsistent interpretations of morphological phylogeny. More generally, we suggest that the evolutionary properties of adaptive radiations may leave current molecular dating methods susceptible to overestimating the timing of major diversification events. |
| first_indexed | 2024-12-17T13:55:30Z |
| format | Article |
| id | doaj.art-1c00ec554fbc4d75a887a28fc215fb1a |
| institution | Directory Open Access Journal |
| issn | 1471-2148 |
| language | English |
| last_indexed | 2024-12-17T13:55:30Z |
| publishDate | 2018-07-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Evolutionary Biology |
| spelling | doaj.art-1c00ec554fbc4d75a887a28fc215fb1a2022-12-21T21:45:56ZengBMCBMC Evolutionary Biology1471-21482018-07-0118111310.1186/s12862-018-1218-xThe soft explosive model of placental mammal evolutionMatthew J. Phillips0Carmelo Fruciano1School of Earth, Environmental and Biological Sciences, Queensland University of TechnologySchool of Earth, Environmental and Biological Sciences, Queensland University of TechnologyAbstract Background Recent molecular dating estimates for placental mammals echo fossil inferences for an explosive interordinal diversification, but typically place this event some 10–20 million years earlier than the Paleocene fossils, among apparently more “primitive” mammal faunas. Results However, current models of molecular evolution do not adequately account for parallel rate changes, and result in dramatic divergence underestimates for large, long-lived mammals such as whales and hominids. Calibrating among these taxa shifts the rate model errors deeper in the tree, inflating interordinal divergence estimates. We employ simulations based on empirical rate variation, which show that this “error-shift inflation” can explain previous molecular dating overestimates relative to fossil inferences. Molecular dating accuracy is substantially improved in the simulations by focusing on calibrations for taxa that retain plesiomorphic life-history characteristics. Applying this strategy to the empirical data favours the soft explosive model of placental evolution, in line with traditional palaeontological interpretations – a few Cretaceous placental lineages give rise to a rapid interordinal diversification following the 66 Ma Cretaceous-Paleogene boundary mass extinction. Conclusions Our soft explosive model for the diversification of placental mammals brings into agreement previously incongruous molecular, fossil, and ancestral life history estimates, and closely aligns with a growing consensus for a similar model for bird evolution. We show that recent criticism of the soft explosive model relies on ignoring both experimental controls and statistical confidence, as well as misrepresentation, and inconsistent interpretations of morphological phylogeny. More generally, we suggest that the evolutionary properties of adaptive radiations may leave current molecular dating methods susceptible to overestimating the timing of major diversification events.http://link.springer.com/article/10.1186/s12862-018-1218-xCretaceous-Paleogene boundaryFossil calibrationLife historyMolecular datingPlacentalia |
| spellingShingle | Matthew J. Phillips Carmelo Fruciano The soft explosive model of placental mammal evolution BMC Evolutionary Biology Cretaceous-Paleogene boundary Fossil calibration Life history Molecular dating Placentalia |
| title | The soft explosive model of placental mammal evolution |
| title_full | The soft explosive model of placental mammal evolution |
| title_fullStr | The soft explosive model of placental mammal evolution |
| title_full_unstemmed | The soft explosive model of placental mammal evolution |
| title_short | The soft explosive model of placental mammal evolution |
| title_sort | soft explosive model of placental mammal evolution |
| topic | Cretaceous-Paleogene boundary Fossil calibration Life history Molecular dating Placentalia |
| url | http://link.springer.com/article/10.1186/s12862-018-1218-x |
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