Harcombe WR, Chacón JM, Adamowicz EM, Chubiz LM, Marx CJ.
Evolution of bi-directional costly mutualism from byproduct consumption.
PNAS. 115:12000-12004 (2018). [pdf] doi.org/10/1073/pnas.1810949115
[Highlighted article by PNAS: Farrell JM and Brown SP, 2018. Evolution of a bacterial trade in a two-species community. 115:11874-11875. doi.org/10.1073/pnas.1817344115]