[chris5745]

I’m not an evolutionary biologist, but I think that the longer an organism’s lifespan is, the slower the rate of reproduction and therefore there will be a slower rate at which the population is capable of evolving. This will put the population at a disadvantage compared to a faster rate of evolving in the event there is environmental pressure.

I think of this as a curve fitting problem: finer granularity of the data points (a shorter lifespan with faster sexual maturation) would more quickly produce a wider variety of genotypes, some of which are more suited to fit to a rapidly changing environment (the curve). On the contrary, rougher granularity of the data (longer lifespan, slower sexual maturation; instead of data points, data line segments trying to fit to the curve) would be more suited to a flatter or gradually shifting curve (a more slowly changing environment).

I think if you have an acute environmental shock, as is happening right now with global warming, the folks who have lots of kids at a younger age will have the genetic advantage from a population perspective (ignoring influences from financial and technological resources).