I just learned of the "aquatic ape theory" by which our ancestors may have progressed through a seaside watery stage in which they adapted to living in and near the water instead of roaming the desert savannas as the standard story goes. This theory could explain our becoming hairless and acquiring a subcutaneous fat layer, just 2 of the traits we share with aquatic mammals such as dolphins. Well, the theory is scoffed upon in the scientific community, although a few such as Desmond Morris are supporters http://aquaticapehypothesis.com/.
As a swimmer, I rather like the idea and choose to entertain thoughts of myself related more closely to the dolphin. Hey, life's a fantasy, anyway. Dream it and be it. Maybe I'm the missing link- I feel more comfortable in the water than on the land and think we should all be swimmers for our physical, mental and spiritual health.