The Amazon River runs for thousands of miles. At some points, it runs through areas of the rain forest that are almost untouched and have been barely explored. Because of the porous limestone in these areas, the river water leaks through the stone and travels deep into the earth and forms underground pools almost a mile below the surface. Over thousands of years, small blind transparent fish have lived and evolved in these pools. These fish have never seen the sun or surface and have never been seen by humans. These fish care more about this than I do.