That argument is not valid because entropy presumes a closed system.
That argument is not valid because entropy presumes a closed system.
No. "Entropy" doesn't presume that. Entropy is just a quantifiable character of a system, whether open, closed or otherwise. But I know what you mean: The 2nd Law of Thermodynamics -- that entropy must increase -- only applies to a closed system.
True enough. The "evolution violates the 2nd law" argument is invalid for that reason also. But my point is even simpler, and simultaneously stronger and broader as well.
Simply pointing that living things are not closed systems means that evolution does not necessarily violate the 2nd Law. But this is a relatively weak case by itself since it does nothing toward suggesting that evolution should occur, but only that it is not prohibited from occurring.
After all, there are any number of open systems in which evolution does not occur, and any number in which entropy does increase despite the system being open.
OTOH, pointing out that living things inherently, systematically, pervasively and continuously reduce entropy (accumulate negentropy) goes beyond the negative case of arguing merely that evolution is not prohibited, and instead indicates that the organized energy to drive processes like evolution actually is available and abundant.
Furthermore, it sidesteps theoretical issues altogether. It is a bald and demonstrable FACT that living organisms reduce entropy, despite and prior to any particular analysis of how they happen to manage doing it.