Trevor R. Hodkinson
Publications (Showing 3 of 3)
Phylogenomics and the rise of the angiosperms
Vol. 629, Issue 8013
pp. 843-850
Angiosperms are the cornerstone of most terrestrial ecosystems and human livelihoods1,2. A robust understanding of angiosperm evolution is required to explain their rise to ecological dominance. So far, the angiosperm tree of life has been determined primarily by means of analyses of the plastid genome3,4. Many studies have drawn on this foundational work, such as classification and first insights into angiosperm diversification since their Mesozoic origins5–7. However, the limited and biased sampling of both taxa and genomes undermines confidence in the tree and its implications. Here, we build the tree of life for almost 8,000 (about 60%) angiosperm genera using a standardized set of 353 nuclear genes8. This 15-fold increase in genus-level sampling relative to comparable nuclear studies9 provides a critical test of earlier results and brings notable change to key groups, especially in rosids, while substantiating many previously predicted relationships. Scaling this tree to time using 200 fossils, we discovered that early angiosperm evolution was characterized by high gene tree conflict and explosive diversification, giving rise to more than 80% of extant angiosperm orders. Steady diversification ensued through the remaining Mesozoic Era until rates resurged in the Cenozoic Era, concurrent with decreasing global temperatures and tightly linked with gene tree conflict. Taken together, our extensive sampling combined with advanced phylogenomic methods shows the deep history and full complexity in the evolution of a megadiverse clade.
DOI:
10.1038/s41586-024-07324-0
Timing and tempo of evolutionary diversification in a biodiversity hotspot: Primulaceae on Indian Ocean islands
Vol. 41, Issue 4
pp. 810-822
Aim
We examined phylogenetic relationships and spatio‐temporal diversification in Indian Ocean Primulaceae, assessing correlations between speciation rates, geographical expansion and ecomorphological specialization.
Location
Madagascar and Indian Ocean Islands.
Methods
We conducted phylogenetic analyses with plastid and nuclear
Results
Indian Ocean Primulaceae were recovered as monophyletic with a sister relationship to Asian Ardisia. Oncostemum, a genus confined to Madagascar and the Comoros, was resolved as paraphyletic by the inclusion of a monophyletic Mascarene Badula group consisting of single‐island endemics. We found evidence for diversification bursts early in the history of Indian Ocean Primulaceae that correspond closely to the sequence of dispersal and the appearance of newly formed Mascarene Islands. Age estimates suggest a dispersal to Rodrigues that is older than the estimated geological age of the island.
Main conclusions
Results suggest a Madagascan origin of Indian Ocean Primulaceae with subsequent dispersal to the Mascarenes in the middle to late Miocene, with initial establishment on either Mauritius or Rodrigues and subsequent stepping‐stone dispersal to the other two Mascarene islands within the last 2 Myr. Analyses suggest that diversification has slowed over time, with significant rate changes following dispersal to new geographical areas. Onset of diversification in species‐rich Oncostemum appears to have been recent, with major cladogenesis commencing in the early Pliocene.
DOI:
10.1111/jbi.12259
Phylogenetic inference of Badula (Primulaceae), a rare and threatened genus endemic to the Mascarene Archipelago
Vol. 169, Issue 2
pp. 284-296
DOI:
10.1111/j.1095-8339.2012.01221.x