Testing Darwin’s transoceanic dispersal hypothesis for the inland nettle family (Urticaceae)

Authors Organisations
  • ZengYuan Wu(Author)
    Kunming Institute of Botany
  • Jie Liu(Author)
    Kunming Institute of Botany
  • Jim Provan(Author)
  • Hong Wang(Author)
    Kunming Institute of Botany
  • Chia-Jui Chen(Author)
    Chinese Academy of Sciences
  • Marc Cadotte(Author)
    University of Toronto
  • Ya-Huang Luo(Author)
    Kunming Institute of Botany
  • Bruno Amorim(Author)
    State University of Amazonas
  • De-Zhu Li(Author)
    Kunming Institute of Botany
  • Richard Milne(Author)
    University of Edinburgh
Type Article
Original languageEnglish
Pages (from-to)1515-1529
Number of pages15
JournalEcology Letters
Volume21
Issue number10
Early online date21 Aug 2018
DOI
Publication statusPublished - 01 Oct 2018
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Abstract

Dispersal is a fundamental ecological process, yet demonstrating the occurrence and importance of long‐distance dispersal (LDD) remains difficult, having rarely been examined for widespread, non‐coastal plants. To address this issue, we integrated phylogenetic, molecular dating, biogeographical, ecological, seed biology and oceanographic data for the inland Urticaceae. We found that Urticaceae originated in Eurasia c. 69 Ma, followed by ≥ 92 LDD events between landmasses. Under experimental conditions, seeds of many Urticaceae floated for > 220 days, and remained viable after 10 months in seawater, long enough for most detected LDD events, according to oceanographic current modelling. Ecological traits analyses indicated that preferences for disturbed habitats might facilitate LDD. Nearly half of all LDD events involved dioecious taxa, so population establishment in dioecious Urticaceae requires multiple seeds, or occasional selfing. Our work shows that seawater LDD played an important role in shaping the geographical distributions of Urticaceae, providing empirical evidence for Darwin's transoceanic dispersal hypothesis.

Keywords

  • biogeography, ecological traits, long-distance dispersal, molecular phylogeny, ocean current, seed viability, Uricaceae