Evaluating the Representation of Community Colleges in Biology Education Research Publications following a Call to Action.

Interest in biology education research (BER) has been growing over the last two decades, yet few BER publications focus on community colleges, which serve a large percentage of the undergraduate student population and a majority of those students who identify with historically underserved groups. In this paper, we define community college biology education research (CC BER) as publications with a community college faculty member as an author, publications with a community college study context or a focus on community college biology teaching and learning, and publications that use community college students as a source of data. We conducted a literature review to quantify how CC BER has progressed since initial calls for broadening participation by recording the number of CC BER publications in seven prominent journals between 2016 and 2020.

Limitation by a shared mutualist promotes coexistence of multiple competing partners.

Although mutualisms are often studied as simple pairwise interactions, they typically involve complex networks of interacting species. How multiple mutualistic partners that provide the same service and compete for resources are maintained in mutualistic networks is an open question. We use a model bacterial community in which multiple 'partner strains' of Escherichia coli compete for a carbon source and exchange resources with a 'shared mutualist' strain of Salmonella enterica.

A shared limiting resource leads to competitive exclusion in a cross-feeding system.

Species interactions and coexistence are often dependent upon environmental conditions. When two cross-feeding bacteria exchange essential nutrients, the addition of a cross-fed nutrient to the environment can release one species from its dependence on the other. Previous studies suggest that continued coexistence depends on relative growth rates: coexistence is maintained if the slower-growing species is released from its dependence on the other, but if the faster-growing species is released, the slower-growing species will be lost (a hypothesis that we call 'feed the faster grower' or FFG).

The evolution of cooperation by the Hankshaw effect.

The evolution of cooperation-costly behavior that benefits others-faces one clear obstacle. Namely, cooperators are always at a competitive disadvantage relative to defectors, individuals that reap the benefits, but evade the cost of cooperation. One solution to this problem involves genetic hitchhiking, where the allele encoding cooperation becomes linked to a beneficial mutation, allowing cooperation to rise in abundance.