evolution is not about adaptability of a species, it's about adaptability of individuals (it's not a centralized decision taken for the well-being of a species, but rather a consequence of individuals having more chances to pass their genes than others. The lucky ones are more adaptive).

If you take 2 individuals and one dies sooner than the later, the alive one will have had more chances to pass his genes, so it's not adaptive to have mechanism to ensure our deaths.