Rampant evolutionary transitions towards the woody growth form

Wood formation is a fundamental evolutionary innovation that gave rise to countless woody species. The evolutionary transition from herbaceousness towards (phylogenetically) derived woodiness is a peculiar phenomenon dating back to Darwin's original observations. However, after about 180 years, scientists still have not figured out why plants became woody and why this has happened so frequently during evolution.

Therefore, we have compiled the first global derived woodiness database with about 7000 species belonging to 700 independent lineages. Most of the derived woody species thrive in continental regions with recurrent drought cycles. This has laid the foundation for our novel hypothesis, proposing drought as a major driver of the evolutionary transitions towards woodiness across most lineages. My team has already obtained preliminary experimental support for this hypothesis in several plant groups, and we are currently looking into alternative drivers of wood formation across flowering plants. Another major research question is whether woodiness has triggered diversification or rather results in an evolutionary dead end.