Reply To: It's Fascinating the Places I Discover Evidence For Evolution

[PopeBeanie]

I also know that the salt ratio in a saline solution approximates the same in oceanic salt water.

“Saline” is about salt, but doesn’t define a specific concentration. It’s true that the concentration of salt used in IVs is about the same as the concentration of salt in the blood, but sea water is 3 to 4 times saltier than blood. It’s interesting that the salinity of sea water may have been a few times lower back when life evolved, and in fact even fish blood has about 1/4 the salinity of sea water, as do most of today’s vertebrates.

So discussing how this with a creationist about how it has to do with evolution could get complicated. 🙂 I’d like to know, for example, why fish did not evolve to have higher salinity blood. I assume it’s because life’s basic metabolic processes at the cellular level were pretty much optimized at the lower levels of salinity, and the goal was to adapt to varying salinities over time, which could only be done at the organ level, e.g. kidneys that could adapt more quickly (but still over millions of years), and adjust blood salinity by the minute.