Lesson B-33. Darwin’s Observations and Reasoning Welcome to BFSU: › Forums › Volume Three › Learning Progression B. Life Sciences › Lesson B-33. Darwin’s Observations and Reasoning This forum has 1 topic, and was last updated 6 years, 6 months ago by CJRichey. Viewing topic 1 (of 1 total) Topic Voices Posts Last Post Reading List Additions for B-33 Started by: CJRichey 1 1 6 years, 6 months ago CJRichey Viewing topic 1 (of 1 total) You must be logged in to create new topics.