Brazilian society was shaken by turmoil in the 1920s and 1930s. The country was rocked by heated debates over race and immigration, burgeoning social movements in cities and the countryside, entrenched oligarchies clinging to power, and nature being despoiled. Against this turbulent backdrop, a group of biology scholars at the National Museum in Rio de Janeiro joined the drive to renew the Brazilian nation, claiming as their weapon the voice of their fledgling field. Without discarding scientific rigor, they embraced biology as a creed and activism as a conviction--and achieved success in...