SO ENDS this first of two weekends on the return to aquatic life of some plants. This is akin to the journey that whales took, returning to the sea after leaving the sea for dry land, equally challenging both anatomically and metabolically. Evolution has numerous examples of similar reversals, classically, flightless birds. With an engine that generates constant diversity in search of a purpose, evolution has this ability sometimes to go one step forward and two steps back. View in LinkedIn