Evolving the Culture of Biology (ECB) is an NSF-funded project that aims to assist teaching assistant – teaching professional development (TA-TPD) practitioners, and the administrators who support them, in designing, implementing, improving and assessing TA training. TAs are responsible for a large proportion of undergraduate instruction, particularly in biology (including freshwater science). TAs also represent the faculty of the future. By training them in inclusive and evidence-based teaching methods early in their careers, we can support them in their current positions, improve the educational experience of their students, and train the next generation of biology and freshwater science educators. Each Summer, we host workshops over 2.5 days in which ECB Scholars, in institutional teams of three members, engage with tools we developed to focus efforts on integrating inclusive, evidence-based teaching practices into TA-TPD. Scholars will learn about TA-TPD, engage with like-minded stakeholders from other institutions in their region, and work with mentors to develop a plan to create or transform a TA-TPD program at their home institution. Scholars leave the workshop with a team-curated action plan that includes creation of a Teachable Unit that they will pilot with their TAs during the academic year. Additionally, Scholar Teams meet bimonthly in Learning Communities which provide support and guidance, and make meaningful progress on their transformational goals. One goal of the ECB project is to generate a repository, the TPD Catalyst, that will house products authored by ECB Scholars. We have hosted 90 Scholars from thirty institutions in the first two years of the program in the Southeast, West, and Pacific Northwest regions. We will share successes of the project thus far and will engage SFS with our call for applications for upcoming workshops.