[rockinghigh]

This is doubtful. All the research I've seen points to very different story. One example:

"the expected annual probability of death for a 65-y-old hunter-gatherer is about 5.3%; in contrast, for 65-y-olds in Japan today, the chance of death is only about 0.8%.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3497824/

[thaumasiotes]

The figure for Japanese elderly today reflects a life expectancy in the 80s. There's nothing weird about a mortality rate of 5% at 65 corresponding to a life expectancy close to 70.