Specialists leave fewer descendants within a region than generalists

Authors

  • Wim A. Ozinga,

    1. Alterra, Wageningen University & Research Centre, Wageningen, The Netherlands
    2. Department of Experimental Plant Ecology, Radboud University Nijmegen, Nijmegen, The Netherlands
    Search for more papers by this author
  • Audrey Colles,

    1. Research Unit ‘Ecosystèmes, Biodiversité, Evolution’, University Rennes 1/Centre National de la Recherche Scientifique, Rennes, France
    Search for more papers by this author
  • Igor V. Bartish,

    1. Research Unit ‘Ecosystèmes, Biodiversité, Evolution’, University Rennes 1/Centre National de la Recherche Scientifique, Rennes, France
    2. Department of Genetic Ecology, Institute of Botany, Academy of Sciences, Czech Republic
    Search for more papers by this author
  • Françoise Hennion,

    1. Research Unit ‘Ecosystèmes, Biodiversité, Evolution’, University Rennes 1/Centre National de la Recherche Scientifique, Rennes, France
    Search for more papers by this author
  • Stephan M. Hennekens,

    1. Alterra, Wageningen University & Research Centre, Wageningen, The Netherlands
    Search for more papers by this author
  • Sandrine Pavoine,

    1. Département Ecologie et Gestion de la Biodiversité, Museum National d'Histoire Naturelle, Paris, France
    2. Mathematical Ecology Research Group, Department of Zoology, University of Oxford, Oxford, UK
    Search for more papers by this author
  • Peter Poschlod,

    1. Institute of Botany, Faculty of Biology and Preclinical Medicine, University of Regensburg, Regensburg, Germany
    Search for more papers by this author
  • Marie Hermant,

    1. Research Unit ‘Ecosystèmes, Biodiversité, Evolution’, University Rennes 1/Centre National de la Recherche Scientifique, Rennes, France
    Current affiliation:
    1. University of Lille 1, CNRS, Laboratoire de Génétique et Evolution des Populations Végétales, Lille, France
    Search for more papers by this author
  • Joop H. J. Schaminée,

    1. Alterra, Wageningen University & Research Centre, Wageningen, The Netherlands
    2. Department of Experimental Plant Ecology, Radboud University Nijmegen, Nijmegen, The Netherlands
    Search for more papers by this author
  • Andreas Prinzing

    Corresponding author
    1. Research Unit ‘Ecosystèmes, Biodiversité, Evolution’, University Rennes 1/Centre National de la Recherche Scientifique, Rennes, France
    • Alterra, Wageningen University & Research Centre, Wageningen, The Netherlands
    Search for more papers by this author

Correspondence: Andreas Prinzing; CNRS, Research Unit ‘Ecobio’, University Rennes 1, Campus Beaulieu Bâtiment 14 A, 35042 Rennes, France.

E-mail: prinzing@univ-rennes1.fr

Abstract

Aim

Current conservation biology suggests that across ecological time-scales specialist species existing in the recent past have left on average fewer descendant populations today than generalist species. Conversely, the speciation literature suggests that on an evolutionary time-scale specialists leave as many or more descendant lineages as generalists, i.e. they have high rates of global diversification. This begs the question: which of these two processes has more influence on the regional scale, i.e. do specialists leave more or fewer descendants than generalists within a region?

Location

The flora of the Netherlands.

Methods

We quantified niche volume of 707 plant species from coexistence data and ecological indicator values and used sister taxon comparisons to compare specialist and generalist sister taxa for the relative numbers of descendants across three temporal scales: ecological, microevolutionary and macroevolutionary.

Results

We show, first, that specialist species are more likely to be currently declining, i.e. to leave only few descendant populations. Second, specialists are less likely to be currently diversifying into intra-specific taxa. Finally, most specialist clades left fewer descendant species within a region than their generalist sister clades. These results were consistent across sublineages, unbiased by geographic sampling of lineages and environments, and held after accounting for species life histories. Differences between specialist and generalist sister clades increased with clade age, suggesting that they reflect differences in rates at which specialists left descendants (rather than differences in ecological limits to the numbers of specialists and generalists).

Main conclusions

Specialists left only few descendants within a region (i.e. the Netherlands), both at ecological, microevolutionary and macroevolutionary scales. While specialists may leave numerous evolutionary descendants at a global scale, these might be absent from most regions. Humans, by threatening specialist species, may hence further accelerate biotic homogenization with descendants of generalist lineages proliferating within regions while specialist lineages disappear.

Ancillary