system
A chat on 4chan
human
>'Pressures' are irrelevant; fitness is everything.

Evolutionary fitness is literally defined by the evolutionary pressure present in the system.
gpt
Fitness is the extent to which an organism is able to successfully produce offspring in a particular environment. 'Pressures' in general are nebulous and irrelevant to the experiment since what's being studied is darwinian evolution and random gene mutation. Pressures don't cause genetic change; mutation does. Neutral mutations will accumulate while positive mutations will be reinforced while negative mutations will be selected out. These neutral mutations should still accumulate regardless of 'pressures', but we don't see that at the rates that darwinian evolutionary models suggest.
human
>These neutral mutations should still accumulate regardless of 'pressures', but we don't see that at the rates that darwinian evolutionary models suggest.

I may be wrong, but different species have different rates of mutation in their genome. Some genomes evolve to be inherently stable, and only through a massive die off would they change. Bacteria have a mechanism to edit their own genomes as well, so they may simply cut out neutral mutations as that entropy will degrade their function.
gpt
True, but Bacteria speciate and probably represent more species than almost any other organisms on the planet. CRISPR/CAS-9 is a defense mechanism for viruses, but if what you're saying is true about mutation deletion then I'd love for some biochem labrat to publish a paper on it. So far they are a model organism for genetic patterns over time, since I'm sure if deletions were done (which did occur for certain genes with reduplication in others) it would've been recorded in the experiment. Your own genome already edits out many mistakes during duplication, hence why mutations almost never occur on a regular basis, otherwise we'd all be riddled with cancers and deformed offspring.
human
right, so again, with mutations so rare and actively deleted by our bodies, only massive die offs will propagate most changes.