In the history of life, single-celled microbes have evolved into multicellular bodies at least 25 times. In our own lineage, our ancestors crossed over some 700 million years ago. In tomorrow’s New York Times, I write about a new study in which single-celled yeast evolved into multicellular forms–completely with juvenile and adult forms, different cell types, and the ability to split off propagules like plant cuttings. All this in a matter of weeks. Check it out.
(The paper is not yet online yet, but here’s the reference: “Experimental evolution of multicellularity,” William C. Ratcliff, R. Ford Denison, Mark Borrello, and Michael Travisano. Proceedings of the National Academy of Sciences. http://www.pnas.org/cgi/doi/10.1073/pnas.1115323109 )
Brewing and ethanol industry scientists have been developing highly flocculating yeast stains for many years. These are brewers rather than bakers yeasts but I wonder how the most highly flocculating strains they have developed compare to those in this study.
[CZ: This multicellularity is different from flocculation.]
Fabulous stuff, and I am not just saying this because I’m going to be joining the authors’ department at the U of Minnesota in the spring! And Will says he had a blast talking to you, Carl.
I guess if you want to get big, growing big cells doesn’t work very well. Curious to why large single cells with complex cytoskeletons and specialized sub-regions never occur. Or have they?
One issue with large cells is that voltage differences across cell membranes are key to cell energy metabolism. Large cells have less membrane area relative to their volume. See Lane and Martin (2010) paper in Nature, my discussion in blog post below, and comments on that post from Mark Reichert, who mentions giant Epulopiscium cells.
In the history of life, single-celled microbes have evolved into multicellular bodies at least 25 times. In our own lineage, our ancestors crossed over some 700 million years ago. In tomorrow’s New York Times, I write about a new study in which single-celled yeast evolved into multicellular forms–completely with juvenile and adult forms, different cell types, and the ability to split off propagules like plant cuttings. All this in a matter of weeks. Check it out.
Very interesting. Our understanding of the evolution of multicellularity also has implications for the way we understand the evolution of sex: see http://ittakes30.wordpress.com/2011/04/12/rewriting-the-history-of-sex/.
Brewing and ethanol industry scientists have been developing highly flocculating yeast stains for many years. These are brewers rather than bakers yeasts but I wonder how the most highly flocculating strains they have developed compare to those in this study.
[CZ: This multicellularity is different from flocculation.]
Fabulous stuff, and I am not just saying this because I’m going to be joining the authors’ department at the U of Minnesota in the spring! And Will says he had a blast talking to you, Carl.
I guess if you want to get big, growing big cells doesn’t work very well. Curious to why large single cells with complex cytoskeletons and specialized sub-regions never occur. Or have they?
John Kubie,
One issue with large cells is that voltage differences across cell membranes are key to cell energy metabolism. Large cells have less membrane area relative to their volume. See Lane and Martin (2010) paper in Nature, my discussion in blog post below, and comments on that post from Mark Reichert, who mentions giant Epulopiscium cells.
http://blog.lib.umn.edu/denis036/thisweekinevolution/2011/01/how_inevitable_was_the_origin.html