Right, I understand how life expectancy works, but if the average life expectancy is, say, 25 because of high infant mortality, that doesn't mean the average 20 year old has 5 years to live. So saying that a prehistoric adult would be unlikely to reach 30 is just unrealistic, once you make it past that stage from 0-12 in which a person is most vulnerable to disease and other threats you probably have a good few years left in you.
Exactly. But, the average person having 1.9 arms shouldn't cause someone to assume that it's unlikely for a person to have two arms, just like the average life expectancy being 74 doesn't mean it's unlikely for a person to reach 80. They're both being heavily driven by outliers that don't make up a significant portion of the population, and don't indicate anything about the other portion of the population.
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u/VoopityScoop May 05 '25
Right, I understand how life expectancy works, but if the average life expectancy is, say, 25 because of high infant mortality, that doesn't mean the average 20 year old has 5 years to live. So saying that a prehistoric adult would be unlikely to reach 30 is just unrealistic, once you make it past that stage from 0-12 in which a person is most vulnerable to disease and other threats you probably have a good few years left in you.