Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers

dc.contributor.authorMaurin, Olivier
dc.contributor.authorMuasya, A. M
dc.contributor.authorCatalan, Pilar
dc.contributor.authorShongwe, Eugene Z
dc.contributor.authorViruel, Juan
dc.contributor.authorWilkin, Paul
dc.contributor.authorvan der Bank, Michelle
dc.date.accessioned2016-11-11T08:15:11Z
dc.date.available2016-11-11T08:15:11Z
dc.date.issued2016-11-08
dc.date.updated2016-11-08T19:02:12Z
dc.description.abstractBackground: Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate. In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have led to modification of reproductive organs and mode of dispersal. Results: The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology and climate, where the fynbos, thicket, succulent karoo and forest biomes meet. Conclusions: Diversification out of forest is associated with major shifts in morphology of the perennial tuber (specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift in pollination trait is observed within the forest, but entry into open habitat does not show association with reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin to just at the base or at the apex of it, or has been even replaced by an elaiosome.
dc.identifier.apacitationMaurin, O., Muasya, A. M., Catalan, P., Shongwe, E. Z., Viruel, J., Wilkin, P., & van der Bank, M. (2016). Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers. <i>BMC Evolutionary Biology</i>, http://hdl.handle.net/11427/22506en_ZA
dc.identifier.chicagocitationMaurin, Olivier, A. M Muasya, Pilar Catalan, Eugene Z Shongwe, Juan Viruel, Paul Wilkin, and Michelle van der Bank "Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers." <i>BMC Evolutionary Biology</i> (2016) http://hdl.handle.net/11427/22506en_ZA
dc.identifier.citationMaurin, O., Muasya, A. M. Catalan, P., Shongwe, E. Z., Viruel, J., Wilkin, P., & van der Bank, M. (2016). Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant's foot tubers. BMC Evolutionary Biology. 2016 Nov 08;16(1), 238.
dc.identifier.ris TY - Journal Article AU - Maurin, Olivier AU - Muasya, A. M AU - Catalan, Pilar AU - Shongwe, Eugene Z AU - Viruel, Juan AU - Wilkin, Paul AU - van der Bank, Michelle AB - Background: Dioscorea is a widely distributed and highly diversified genus in tropical regions where it is represented by ten main clades, one of which diversified exclusively in Africa. In southern Africa it is characterised by a distinct group of species with a pachycaul or “elephant’s foot” structure that is partially to fully exposed above the substrate. In contrast to African representatives of the genus from other clades, occurring mainly in forest or woodland, the pachycaul taxa and their southern African relatives occur in diverse habitats ranging from woodland to open vegetation. Here we investigate patterns of diversification in the African clade, time of transition from forest to more open habitat, and morphological traits associated with each habitat and evaluate if such transitions have led to modification of reproductive organs and mode of dispersal. Results: The Africa clade originated in the Oligocene and comprises four subclades. The Dioscorea buchananii subclade (southeastern tropical Africa and South Africa) is sister to the East African subclade, which is respectively sister to the recently evolved sister South African (e. g., Cape and Pachycaul) subclades. The Cape and Pachycaul subclades diversified in the east of the Cape Peninsula in the mid Miocene, in an area with complex geomorphology and climate, where the fynbos, thicket, succulent karoo and forest biomes meet. Conclusions: Diversification out of forest is associated with major shifts in morphology of the perennial tuber (specifically an increase in size and orientation which presumably led them to become pachycaul) and rotation of stem (from twining to non-twining). The iconic elephant's foot morphology, observed in grasslands and thicket biomes, where its corky bark may offer protection against fire and herbivory, evolved since mid Miocene. A shift in pollination trait is observed within the forest, but entry into open habitat does not show association with reproductive morphology, except in the seed wing, which has switched from winged all round the seed margin to just at the base or at the apex of it, or has been even replaced by an elaiosome. DA - 2016-11-08 DB - OpenUCT DO - 10.1186/s12862-016-0812-z DP - University of Cape Town J1 - BMC Evolutionary Biology LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers TI - Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers UR - http://hdl.handle.net/11427/22506 ER - en_ZA
dc.identifier.urihttp://dx.doi.org/10.1186/s12862-016-0812-z
dc.identifier.urihttp://hdl.handle.net/11427/22506
dc.identifier.vancouvercitationMaurin O, Muasya A M, Catalan P, Shongwe EZ, Viruel J, Wilkin P, et al. Diversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers. BMC Evolutionary Biology. 2016; http://hdl.handle.net/11427/22506.en_ZA
dc.language.rfc3066en
dc.publisherBioMed Central
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.rightsCreative Commons Attribution 4.0 International (CC BY 4.0)
dc.rights.holderThe Author(s).
dc.rights.urihttps://creativecommons.org/licenses/by/4.0/
dc.sourceBMC Evolutionary Biology
dc.source.urihttps://bmcevolbiol.biomedcentral.com/
dc.subject.otherBiogeography
dc.subject.otherDioscoreales
dc.subject.other“elephant’s foot”
dc.subject.otherFire adaptation
dc.subject.otherHabitat transition
dc.subject.otherPachycaul
dc.subject.otherSouthern Africa
dc.subject.otherYams
dc.titleDiversification into novel habitats in the Africa clade of Dioscorea (Dioscoreaceae): erect habit and elephant’s foot tubers
dc.typeJournal Article
uct.type.filetypeText
uct.type.filetypeImage
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