title: Incongruent range dynamics between co-occurring Asian temperate tree species facilitated by life history traits.
abstract: Postglacial expansion to former range limits varies substantially among species of temperate deciduous forests in eastern Asia. Isolation hypotheses (with or without gene flow) have been proposed to explain this variance, but they ignore detailed population dynamics spanning geological time and neglect the role of life history traits. Using population genetics to uncover these dynamics across their Asian range, we infer processes that formed the disjunct distributions of Ginkgo biloba and the co-occurring Cercidiphyllum japonicum (published data). Phylogenetic, coalescent, and comparative data suggest that Ginkgo population structure is regional, dichotomous (to west-east refugia), and formed ˜51 kya, resulting from random genetic drift during the last glaciation. This split is far younger than the north-south population structure of Cercidiphyllum (~1.89 Mya). Significant (recent) unidirectional gene flow has not homogenized the two Ginkgo refugia, despite 2Nm > 1. Prior to this split, gene flow was potentially higher, resulting in conflicting support for a priori hypotheses that view isolation as an explanation for the variation in postglacial range limits. Isolation hypotheses (with or without gene flow) are thus not necessarily mutually exclusive due to temporal variation of gene flow and genetic drift. In comparison with Cercidiphyllum, the restricted range of Ginkgo has been facilitated by uncompetitive life history traits associated with seed ecology, highlighting the importance of both demography and lifetime reproductive success when interpreting range shifts.
authors.affiliation: The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education College of Life Sciences Zhejiang University Hangzhou 310058 China; Laboratory of Systematic and Evolutionary Botany and Biodiversity Institute of Ecology and Conservation Centre for Gene Resources of Endangered Wildlife Zhejiang University Hangzhou 310058 China.
authors.forename: Yun-Peng
authors.initials: YP
authors.lastname: Zhao
authors.affiliation: The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education College of Life Sciences Zhejiang University Hangzhou 310058 China; Shanghai Chenshan Plant Science Research Centre Chinese Academy of Sciences Shanghai Chenshan Botanical Garden Shanghai 201602 China.
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Yan
authors.affiliation: Department of Biodiversity and Plant Systematics Centre for Organismal Studies University of Heidelberg Im Neuenheimer Feld 345 69120 Heidelberg Germany.
authors.forename: Graham
authors.initials: G
authors.lastname: Muir
authors.affiliation: Laboratory of Systematic and Evolutionary Botany and Biodiversity Institute of Ecology and Conservation Centre for Gene Resources of Endangered Wildlife Zhejiang University Hangzhou 310058 China.
authors.forename: Qiong-Yan
authors.initials: QY
authors.lastname: Dai
authors.affiliation: Department of Biodiversity and Plant Systematics Centre for Organismal Studies University of Heidelberg Im Neuenheimer Feld 345 69120 Heidelberg Germany.
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Koch
authors.affiliation: The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education College of Life Sciences Zhejiang University Hangzhou 310058 China; Laboratory of Systematic and Evolutionary Botany and Biodiversity Institute of Ecology and Conservation Centre for Gene Resources of Endangered Wildlife Zhejiang University Hangzhou 310058 China.
authors.forename: Cheng-Xin
authors.initials: CX
authors.lastname: Fu
keywords: Asymmetric gene flow; FST; Ginkgo biloba; late‐Pleistocene divergence; lifetime reproductive success; random genetic drift; temporal dynamics