Is blood plasma salinity the same as seawater? No, but that proves evolution. "The answer is most definitely NOT that oceans were 1/3 as salty back then. It most definitely IS that the earliest vertebrates did evolve in salt water and then moved into fresh water....They have devised an extremely clever trick in kidney structure to allow salt transport pumps which really take salt back INTO the body from the urine but still manage to use them to produce urine much more concentrated that their body fluids and so excrete salt FROM the body."
posted by Brian B. on Feb 10, 2007 - 66 comments

Salt: Not just a condiment, salt is a major force shaping our world. In Australia, what do you get when you combine ancient salt-pans with European farming practices? In one state alone, we're losing a football field an hour to the salinity crisis. What do you farm when all you have is salt?
posted by ninazer0 on Nov 25, 2006 - 33 comments