Macroevolutionary data suggest a role for reinforcement in pollination system shifts.
Reproductive isolation can evolve either as a by-product of divergent selection or through reinforcement. We used the Cape flora of South Africa, known for its high level of pollination specialization, as a model system to test the potential role of shifts in pollination system in the speciation process. Comparative analysis of 41 sister-species pairs (representing Geraniaceae, Iridaceae, and Orchidaceae) for which complete pollinator, edaphic, and distribution data are available showed that for sister species with overlapping distribution ranges, pollination system shifts are significantly associated with edaphic shifts. In contrast, there is no significant association between pollination system shifts and edaphic shifts for allopatric sister species. These results are interpreted as evidence for reinforcement.
van der Niet
Timotheüs
T
Institute of Systematic Botany, University of Zurich, Zollikerstrasse 107, 8008, Zurich, Switzerland. niet@systbot.unizh.ch
Johnson
Steven D
SD
Linder
H Peter
HP
D005075:Biological Evolution; D003710:Demography; D027621:Iridaceae / Q000235:genetics / Q000502:physiology*; D029595:Orchidaceae / Q000235:genetics / Q000502:physiology*; D031316:Pelargonium / Q000235:genetics / Q000502:physiology*; D011058:Pollen / Q000235:genetics / Q000502:physiology*; D012098:Reproduction / Q000235:genetics / Q000502:physiology; D013019:South Africa