“This is the most exciting and important paper on big questions about eukaryotic origins and the tree of life in years,” said evolutionary biologist Jeffrey Palmer of Indiana University, Bloomington, ...

Trends in Ecology and Evolution 24, 119–121 (2009) doi:10.1016/j.tree ... Keeling, P. J. Chromalveolates and the evolution of plastids by secondary endosymbiosis. Journal of Eukaryotic ...

These functional types do not correspond to natural groups, because they occur in an interleaved manner across the tree of eukaryotic life. Instead they correspond to ecological specializations.