Considering abundancies...?

Question

...why is it that (bearing in mind survival of species, et al) all species did not evolve to drink salt water?

(Even land-dwellers are surrounded by more sea water than fresh and as we evolved from the sea anyway [so I'm assuming at this point assimilation of sea water was the chosen hydrant] wouldn't it have been more logical (naturally selective) to remain with what was to that point inbred and abundant rather than specialising on a vital, but less abundant source of hydration (survival) ?)

Answer 1

You would think so wouldnt you!  In a way we do use it through desalination though!

Answer 2

Our ancestors got out of the rat race (overcrowded sea) by climbing on to land. When the land became overcrowded some of us went back in (dolphins, turtles). If your question is just about drinking saltwater then I guess we could but we would have to populate just the fringes of the land mass.

Answer 3

the number and mass of "animals"that utilise `fresh`water is a lot less than those who utilise saline water.thus evolution did favour the !sea!

Answer 4

Natural selection has no plan in mind and no such goal would be considered, unless the proper mutation and selection pressure, your salt water in this case, went hand in hand. Obviously, that did not happen. By the way, we keep that sea we evolved from in us.

Answer 5

Yes, I never thought of that. I must say that lode is still a very important element for our species.

Answer 6

Because we didn't evolve. God made us.

Answer 7

I agree this is a great question.  The human organism can drink a limited amount of salt water, I believe it is one cup a day, which will replenish the salt lost through urination and sweat.  More than that actually begins to dehydrate you.  SO my conclusion is that for other reasons we are intolerant of an over abundance of salt.  Sea water contains too high a concentration to be disposed of through urine and sweat.  It would have required an adaptation to process this excess salt.  Evolution does not generally see a problem and provide a solution.  Generally there is a change with either a benefit or with no deleterious effect that gets passed along until it is selected for.  If there had been a person or animal that evolved this trait but got killed and did not pass it on or failed to have offspring for another reason then it never got selected for.  Giraffes didn't grow long necks so they could eat the highest leaves, a Giraffe that had a slightly longer neck was able to find food when others couldn't and therefore passed on this trait to its offspring.  But, wouldn't it be cool if some people or animals could dispose of the excess salt, a sort of natural, biological desalination plant.

Answer 8

this is old, very old information, Time Life came up in the 70's with a sort of encyclopedia and my dad gave it to me as a gift. anyway there i read that there were around 30,000 species of fish, then there are Marine reptiles, invertebrates, etc. see there is life in the sea we just don't know exactly how much and how many kinds. until the 60,s study of deep oceans was limited to the government here in the US.

we may not be able to live under water but many many species have been doing it for millions of years.

Answer 9

Wow good question. You have challenged me to do some research. Thank you for that. I will get back to you when I have a conclusion.

Answer 10

All mammals, birds and reptiles descend from amphibians who by and large developed from fresh water fish. Fresh water fish and salt water fish have very different methods for maintaining the water and electrolyte balance between their bodies and their environments. If we were to consume saltwater in the way we consume freshwater we'd rapidly dehydrate and die. It's like when you put fish in the wrong tanks. Saltwater fish in freshwater get all puffy and die (their cells explode, literally) and freshwater fish in saltwater shrivel like slugs trapped by kids with salt shakers.

Answer 11

This makes me wonder;  How salty is a Sizzlebeaver and how long could a man be sustained by it?