On almost all worlds, life evolves in a liquid. This is reasonable as the liquid provides mobility, and increases greatly the chances that any complex molecule will encounter another. If one examines the physical structure of intelligent species, one finds rudimentary gills, fins, egg sacs, webbing, if not the frank requirement of a liquid for the home. Most telling is the development of the fetus, where the evolutionary history repeats itself. We, the Zetas, do not have records we can tap regarding these early beginnings on your planet. Planets, especially water planets, are seeded with simple DNA components and left alone. Things work out or they don't, and these planets are not checked that frequently. If life did not start, re-seeding, perhaps of a different nature, is done. To trace your beginnings, we must do as your scientists have, and look at the stages the fetus goes through. The forebrain develops last, and arms and legs also come late. It takes a long time for the tail to disappear, and gills are unmistakably evident in the early days. You were first a fish.