Maureen O’Malley and Russell Powell say that the major transitions framework is in need of repair. They have a point, or rather several good points. I have looked at their criticisms of three different versions (the original framework as laid out in the book by John Maynard Smith and Eörs Szathmáry, Rick Michod’s ‘evolutionary transitions in individuality‘ framework, and Szathmáry’s revised ‘Major Transitions 2.0‘). But what is their proposed fix, and will it have the intended effect?

Figure 4 from O’Malley and Powell 2016. Two major aeons of evolution (modified from Falkowski 2006). ‘Gya’ stands for ‘billion years ago’; the date for the origin of photosynthesis may need to be pushed back (see Crowe et al. 2013).