Pretty much what the title says: the meeting review from Volvox 2015 is online early at Molecular Ecology. That only took six months! This is the final, published version. Thanks for a great meeting, and thanks to everyone who read earlier drafts!
A new(ish) paper in National Science Review evaluates the evidence for various interpretations of Ediacaran microfossils from the Weng’an biota in South China (Xiao et al. 2014. The Weng’an biota and the Ediacaran radiation of multicellular eukaryotes. Natl. Sci. Rev., 1:498–520.). I recommend checking it out; it’s open access, and there’s a lot of interesting stuff in there that I’m not going to address.
These fossils are undoubtedly multicellular, probably eukaryotic, and extremely enigmatic. Their age (582-600 million years) means they could have important implications for the evolution of multicellularity, and their exceptional preservation in great numbers creates the potential for reconstructing their life cycles in great detail. Some of the Weng’an fossils have been interpreted as volvocine algae, an interpretation that I find highly unlikely.
Some of the Weng’an fossils are thought to represent red algae, and this would not be terribly surprising, since red algae have been around for at least 1.2 billion years. Others, for example the tubular fossils, are more problematic, with interpretations as diverse as cyanobacteria, eukaryotic algae, crinoids, and cnidarians.
Among the lower Algae there is a family, the Volvocinæ, in which the differentiation of the many-celled body on the principle of division of labour has just set in; in some genera it has been actually effected, though in the simplest way imaginable, and in others it has not yet begun.