Interesting review of the concept of the human body as an ecosystem. These days I don't think too many biological scientists in his audience would have needed the "lake" analogy to understand the idea, though some may have been interested in the history of the alewives as a wellknown ecological case study in itself.
A bit wordy at the start but overall very good.
PS, the author was science writer Carl Zimmer, not Hutchinson, who was an early ecologist described in the article.