Integrating fossils, phylogenies, and niche models into biogeography to reveal ancient evolutionary history: the case of Hypericum (hypericaceae).
In disciplines such as macroevolution that are not amenable to experimentation, scientists usually rely on current observations to test hypotheses about historical events, assuming that "the present is the key to the past." Biogeographers, for example, used this assumption to reconstruct ancestral ranges from the distribution of extant species. Yet, under scenarios of high extinction rates, the biodiversity we observe today might not be representative of the historical diversity and this could result in incorrect biogeographic reconstructions. Here, we introduce a new approach to incorporate into biogeographic inference the temporal, spatial, and environmental information provided by the fossil record, as a direct evidence of the extinct biodiversity fraction. First, inferences of ancestral ranges for those nodes in the phylogeny calibrated with the fossil record are constrained to include the geographic distribution of the fossil. Second, we use fossil distribution and past climate data to reconstruct the climatic preferences and potential distribution of ancestral lineages over time, and use this information to build a biogeographic model that takes into account "ecological connectivity" through time. To show the power of this approach, we reconstruct the biogeographic history of the large angiosperm genus Hypericum, which has a fossil record extending back to the Early Cenozoic. Unlike previous reconstructions based on extant species distributions, our results reveal that Hypericum stem lineages were already distributed in the Holarctic before diversification of its crown-group, and that the geographic distribution of the genus has been relatively stable throughout the climatic oscillations of the Cenozoic. Geographical movement was mediated by the existence of climatic corridors, like Beringia, whereas the equatorial tropical belt acted as a climatic barrier, preventing Hypericum lineages to reach the southern temperate regions. Our study shows that an integrative approach to historical biogeography-that combines sources of evidence as diverse as paleontology, ecology, and phylogenetics-could help us obtain more accurate reconstructions of ancient evolutionary history. It also reveals the confounding effect different rates of extinction across regions have in biogeography, sometimes leading to ancestral areas being erroneously inferred as recent colonization events.
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK asanchezmeseguer@gmail.com isanmartin@rjb.csic.es.
Andrea S
AS
Meseguer
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Jorge M
JM
Lobo
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Richard
R
Ree
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
David J
DJ
Beerling
Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Plaza de Murillo 2, 28014 Madrid, Spain; INRA, UMR 1062 CBGP Campus International de Baillarguet, 34988 Montferrier-sur-Lez, France; Department of Biogeography and Global Change, Museo Nacional Ciencias Naturales-CSIC, 28006 Madrid, Spain; Department of Botany, Field Museum of Natural History, Chicago, IL 60605, USA and Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
Isabel
I
Sanmartín
D053476:Extinction, Biological; D005580:Fossils; D005843:Geography; D020902:Hypericum / Q000033:anatomy & histology / Q000145:classification*; D008954:Models, Biological; D010802:Phylogeny; D012639:Seeds / Q000033:anatomy & histology
Biogeography; Cenozoic climate change; Hypericum; environmental niche modeling; extinction; fossils; phylogenetics