Indeed. Twice the atmospheric pressure by itself would definitely affect the human body in many ways. Our red blood cells are capable of holding a limited amount of O2. Even at a simple 23%, the human body would do better, heal faster, etc. At 2 atmospheres and with the increased O2 and CO2 saturations the entire ecosystem of our world would be enhanced. Size would increase as would longevity. Giant animal fossils are found throughout the world. A butterfly or moth with a four foot wingspan. Giant sloths, beavers ...Experiments in the hyperbaric chamber in Texas showed cuts on an arm healed in a day. Both plants and animals were positively affected. When birds and fish were placed in the chamber, together some symbiotic interactions were noted. Interesting since the Bible declares they were created on the same day.
