Publications (Showing 2 of 2)

Phylogenomics and the rise of the angiosperms

Nature
2024

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

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The role of Antarctica in biogeographical reconstruction: A point of view

International Journal of Plant Sciences
2019

Vol. 180, Issue 1

pp. 63-71

Premise of research. The opening of the Drake Passage in the Miocene (disconnecting Antarctica and South America and resulting in the establishment of the Circumpolar Current preventing warm waters from the north to reach the polar continent) has led to the formation of the ice sheets and the retreat of the temperate to tropical vegetation that had covered Antarctica for millions of years. With only two current native vascular plant species, Antarctica has been virtually ignored in biogeographical reconstructions and, when considered, only a posteriori invoked as a route of dispersal to reconcile inferred disjunct biogeographical patterns. Methodology. Here, we provide a brief overview of the rich fossil record of Antarctica, further confirming that many plant families were once present on this continent and that the age of a family is mostly not correlated with its presence or absence on the continent. Such evidence indicates a need to develop a paleogeographical model incorporating Antarctica that can be applied to constrain ancestral area reconstructions. We propose such a model and investigate its effects on biogeographical scenarios using the cosmopolitan plant family Myrtaceae (a family with a rich fossil record in Antarctica) as a case study. Pivotal results. Based on this evidence and previous studies that have shown the importance of Antarctica in the biogeography and evolution of plant lineages, we argue that this region should routinely be included as a predefined area in biogeographical analyses. Conclusions. A possible paleogeographical model including Antarctica is proposed. It is subdivided into five time slices and spans the last 160 Myr. We expect that the formal inclusion of Antarctica in ancestral area reconstructions (using an evidence-based biogeographical model) will open further discussions and research programs assessing the importance of this area in shaping the current temperate and tropical floras and increase the precision of resulting biogeographical patterns.

DOI:

10.1086/700581

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Eve J. Lucas | Flora of the World