Integrative approaches to understanding angiosperm origins and diversity

The rise of angiosperms should be studied as part of the global increase in biodiversity.

Angiosperms are the most species-rich group of land plants, but their origins, together with their rapid and intense diversification still requires an explanation. More elaborate explanations can arise from studying evolutionary trends across taxa and throughout the Phanerozoic, as well as from integration between ideas that come from varying disciplines.

Species development over time
(A) Number of plant species (redrawn from Niklas et al., 1983) and (B) number of tetrapod families (redrawn from Sahney et al., 2010a) belonging to major clades throughout the Phanerozoic. Dots represent maximal species/family number ever recorded at a single point in the palaeontological record against the estimated time of initial evolutionary radiation and success. Note that ‘gymnosperms’ in this figure also includes angiosperm ancestors (between the gene divergence time of extant gymnosperms and angiosperm approximately 350Mya and the first emergence of true angiosperms), as described in the section ‘New Chronology Opens New Horizons’. Key to geological periods: O, Ordovician; S, Silurian; D, Devonian; C, Carboniferous; P, Permian; T, Triassic; J, Jurassic; K, Cretaceous; Pg, Palaeogene; Ng, Neogene. Full details in Katz (2018).

Descriptions of evolutionary chronologies should integrate between molecular phylogenies, descriptive palaeontology and palaeoecology. Katz explores the theory that ‘biodiversity creates biodiversity’ with evidence from past and present ecologies, in particular focusing upon the effect changes in herbivory and resource availability during the Phanerozoic period.

Further reading

Katz, O. (2017). Extending the scope of Darwin’s “abominable mystery”: integrative approaches to understanding angiosperm origins and species richness. Annals of Botany, 121(1), 1–8.