I have been disloyal to the fierce roller. After grad school, I stepped away from Volvox for a couple of years to do a postdoc with Michael Doebeli at the University of British Columbia. I thought I was going to transition to mathematical modeling, and Dr. Doebeli and I did do a bit of that together. I also got my first exposure to next-generation sequencing in his lab. I eventually returned to the fold, but during my time in Canada I wasn’t paying much attention to the Volvox world.
As a result, I missed Jerry Coyne’s coverage of the Volvox genome, which was published in 2010, just as I was discovering Jericho Beach, enjoying cheap sushi, and struggling to understand adaptive dynamics.
The authors’ conclusion? Not many new genes have to change to turn a single cell into a multicellular, proto-differentiated species. In the Science news piece on this article, plant biologist Arthur Grossman comments: “The findings suggest that it doesn’t take very large changes in gene content to transition from a single-cell to a multicellular lifestyle.”
Is this surprising? Well, not really. I’m not sure most biologists would have suggested that multicellularity requires a wholesale restructuring of the types of proteins present in one-celled species. If that were true, it would be very difficult to go from one-cell to multi-cells in an adaptive, step-by-step fashion.. I would have thought that changes in protein sequence (not type) were important and, perhaps, changes in how genes are used—how they are turned on and off, and when.