by Sivan Kaminski Strauss, Dvir Schirman, Ghil Jona, Aaron N. Brooks, Aditya M. Kunjapur, Alex N. Nguyen Ba, Alice Flint, Andras Solt, Andreas Mershin, Atray Dixit, Avihu H. Yona, Bálint Csörgő, Bede Phillip Busby, Bianca P. Hennig, Csaba Pál, Daniel Schraivogel, Daniel Schultz, David G. Wernick, Deepa Agashe, Dikla Levi, Dmitry Zabezhinsky, Dor Russ, Ehud Sass, Einat Tamar, Elad Herz, Emmanuel D. Levy, George M. Church, Idan Yelin, Iftach Nachman, Jeffrey E. Gerst, Joseph M. Georgeson, Katarzyna P. Adamala, Lars M. Steinmetz, Marc Rübsam, Markus Ralser, Michael Klutstein, Michael M. Desai, Nilima Walunjkar, Ning Yin, Noa Aharon Hefetz, Noah Jakimo, Olga Snitser, Omri Adini, Prashant Kumar, Rachel Soo Hoo Smith, Razi Zeidan, Ronen Hazan, Roni Rak, Roy Kishony, Shannon Johnson, Shira Nouriel, Sibylle C. Vonesch, Simmie Foster, Tal Dagan, Tanita Wein, Thrasyvoulos Karydis, Timothy M. Wannier, Timothy Stiles, Viridiana Olin-Sandoval, William F. Mueller, Yinon M. Bar-On, Orna Dahan, Yitzhak Pilpel
In experimental evolution, scientists evolve organisms in the lab, typically by challenging them to new environmental conditions. How best to evolve a desired trait? Should the challenge be applied abruptly, gradually, periodically, sporadically? Should one apply chemical mutagenesis, and do strains with high innate mutation rate evolve faster? What are ideal population sizes of evolving populations? There are endless strategies, beyond those that can be exposed by individual labs. We therefore arranged a community challenge, Evolthon, in which students and scientists from different labs were asked to evolve Escherichia coli or Saccharomyces cerevisiae for an abiotic stress—low temperature. About 30 participants from around the world explored diverse environmental and genetic regimes of evolution. After a period of evolution in each lab, all strains of each species were competed with one another. In yeast, the most successful strategies were those that used mating, underscoring the importance of sex in evolution. In bacteria, the fittest strain used a strategy based on exploration of different mutation rates. Different strategies displayed variable levels of performance and stability across additional challenges and conditions. This study therefore uncovers principles of effective experimental evolutionary regimens and might prove useful also for biotechnological developments of new strains and for understanding natural strategies in evolutionary arms races between species. Evolthon constitutes a model for community-based scientific exploration that encourages creativity and cooperation.