The origin and early evolution of plants.

Area of Science:

• Evolutionary biology
• Paleontology
• Genomics

Background:

• Plant (archaeplastid) evolution profoundly impacted Earth's biosphere.
• Understanding plant origins and evolution is crucial for comprehending Earth system changes.

Purpose of the Study:

• To elucidate the evolutionary history and phylogeny of major plant clades (Archaeplastida, Viridiplantae, Streptophyta).
• To resolve the evolution of key plant characters, genes, and genomes.
• To investigate the coevolution of plants with the Earth system.

Main Methods:

• Comparative genomics
• Phylogenetics
• Fossil record analysis
• Molecular clock analyses

Main Results:

• Illuminated the phylogeny of Archaeplastida, Viridiplantae, and Streptophyta.
• Revealed that many key plant innovations evolved much earlier than previously associated with specific clades.
• Estimated emergence times: Archaeplastida in the late-mid Palaeoproterozoic; Streptophyta and Viridiplantae in the late Mesoproterozoic to late Neoproterozoic.

Conclusions:

• Plant evolution is deeply rooted, with innovations predating their associated clades.
• Early plant evolution significantly influenced Earth's ecology, biogeochemical cycles, weathering, and climate events like 'snowball Earth'.
• Plants played a critical role in oxygen production and net primary productivity (NPP) throughout Earth's history.