Supplementary figures from Sympatric speciation in mountain roses (<i>Metrosideros</i>) on an oceanic island
Owen G. Osborne
Tane Kafle
Tom Brewer
Mariya P. Dobreva
Ian Hutton
Vincent Savolainen
10.6084/m9.figshare.12423710.v1
https://rs.figshare.com/articles/journal_contribution/Supplementary_figures_from_Sympatric_speciation_in_mountain_roses_i_Metrosideros_i_on_an_oceanic_island/12423710
Shifts in flowering time have the potential to act as strong prezygotic reproductive barriers in plants. We investigate the role of flowering time divergence in two species of mountain rose (<i>Metrosideros</i>) endemic to Lord Howe island, Australia, a minute and isolated island in the Tasman sea. <i>Metrosideros nervulosa</i> and <i>M. sclerocarpa</i> are sister species and have divergent ecological niches on the island but grow sympatrically for much of their range, and likely speciated <i>in situ</i> on the island. We used flowering time and population genomic analyses of population structure and selection, to investigate their evolution, with a particular focus on the role of flowering time in their speciation. Population structure analyses showed the species are highly differentiated and appear to be in the very late stages of speciation. We found flowering times of the species to be significantly displaced, with <i>M. sclerocarpa</i> flowering 53 days later than <i>M. nervulosa</i>. Furthermore, the analyses of selection showed that flowering time genes are under selection between the species. Thus, prezygotic reproductive isolation is mediated by flowering time shifts in the species, and likely evolved under selection, to drive the completion of speciation within a small geographical area.This article is part of the theme issue ‘Towards the completion of speciation: the evolution of reproductive isolation beyond the first barriers’.
2020-06-04 08:59:03
flowering time
phenology shifts
reproductive isolation
reproductive character displacement
reinforcement
ecological speciation