system
Given the following post, respond as if you're commenting on Reddit:
human
Does evolution opt for lifespan?


Is there any reason why evolution would cause variances in life span? I guess I’m just curious why there are discrepancies in the lifespans of organisms. If it inevitably rids the gene pool of disease and defects, should lifespans continually expand over time? Thank you in advance.
gpt
Organisms just have to be alive long enough to reproduce and depending on species also do "community stuff" (like e.g. care for young). That's like the general rule of thumb. There are also factors like for example metabolism. The higher the metabolic rate, the more things like oxidative stress occur, muscles get damaged, dna gets damaged, etc. So the shorter those will live, unless they also develop mechanisms to repair such damage again in order to be alive long enough to reproduce.