>> find it quite interesting that no single human ever has achieved even close to [160 years]. Human mortality varies widely, but one relationship seems const

>> find it quite interesting that no single human ever has achieved even close to [160 years]. Human mortality varies widely, but one relationship seems constant: death rate increases exponentially with age. A mortality table from 2011 shows males age 40 have a death rate of 2.1 per thousand; at age 100 the death rate is 357.9 per thousand. That's an increase of a factor of 170 over 60 years, or about 9% per year. Mortality graphs are almost straight lines on semilog plots. Different groups (men versus women, different countries, etc.) show different y-intercepts but the slopes of all these mortality curves is about the same. From this we can deduce that males aged 104 (in this sample) have about a 50% chance of dying within the next year: another way of saying their life expectancy is 1 year. Mortality rates which increase 9% a year, will double in 8 years. So a male aged 112 will have a life expectancy of 6 months. At age 120, 3 months. And so on. That's why we don't see many humans older than 110 or so, and why no one has lived past 130.