AMAP Seminar - Results & Programs

The importance of fossil data in plant macroevolution

06/05/2021 de 11h00 à 12h30Webinar

Modern evolutionary theory finds its very foundations in the differential survival of individuals.One of the implications of differential survival on geological timescales, the extinction of species, is however often overlooked. The reality of extinction implies that the comparative study of living organisms offers only a small window on Macroevolutionary patterns and processes. Many aspects of the biology of extant clades, such as trait evolution, diversity dynamics, and biogeographical history, are only accessible by looking at the fossil record while understanding the taphonomic and geological processes governing its formation. Even thus, the palaeobiological research program in macroevolution has been dwarfed by the expansion of the comparative phylogenetic program, especially after the increased ease of collection of molecular data and the extensive statistical toolbox developed to infer processes from molecular phylogenies.
Plants, due to their continuous development and differential senescence of different organs,seldom fossilize as whole organisms. Moreover, different taphonomic filters act on different plantorgans, so that fossiliferous beds preserving a good pollen record might be completely devoid ofleaves and other macrofossils and vice versa. Here I will show that a careful evaluation of the fossilrecord, and the integration of fossil evidence in a phylogenetic framework including extant diversity,can lead us to reject deep-held believes and hypotheses on the evolution of a charismatic plantgroups, such as Cycadales, Gnetales, and Angiosperms.