Biology in Context ("bik") is a project that aims to improve biology teaching in lower secondary schools in Germany. Based on a theoretical framework derived from the National Educational Standards, four competence areas should be fostered in biology education: subject knowledge; inquiry acquisition; subject-related communication; and valuing and decision making. Therefore, science education researchers and teachers work together in learning communities to transform theoretical competence models in teaching and learning practice using authentic contexts. Funded by the German Federal Ministry of Education and the participating federal states, such learning communities were established. The accompanying formative evaluation research focuses on teachers' professional learning by analysing their attitudes, intentions and behaviour in implementing the "bik" project. The methodology involved questionnaires and structured interviews with teachers, science education researchers and coordinators in the initial phase, after one year of working together and finally at the completion of the "bik" project. The data show that the learning communities have inspired and supported the participating biology teachers to change their teaching towards a more competence-oriented and student-based teaching. The continuing study/work will now focus especially on interdisciplinary working in natural science context projects and in the development of diagnostic tasks to foster different biological competences. (Contains 3 boxes, 4 tables and 5 figures.)