>> 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.
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.