[arbitrage]

> the stories of Enoch and Methuselah show that any hard bound was clearly violated

you're taking things a little literally here; that's perfectly explainable, and is also paralleled in the other mythos you mentioned: a group of people would raise their own status by claiming to be descended from gods or demi-gods or something else extraordinary. Probably the most approachable example of this in western literature is the figure of Herakles/Hercules.

it is not a stretch to imagine that the people responsible for writing certain books of the hebrew bible raised their own status by claiming to be descended from extremely long-lived ancestors.

Additionally, methusaleh's obtained age was recorded as 969 years; this should be understood not literally, but figuratively: 969 is a looooooong time, and a mystical number. It means "this is important, pay attention to this. this person is special". It helps the narrative in an oral tradition.

[TeMPOraL]

Alternatively, you could notice that the abnormally-long lifespans match a pattern of exponential decay towards a new equilibrium. This would be consistent with a hypothesis that there was a lifespan-extending factor involved, which effects grew weaker from generation to generation. The factor could perhaps have been environmental, or genetic.

I don't subscribe to this view, because I no longer believe the stuff described in the Bible actually happened as described - but if I were trying to treat the Genesis stories as real, this would be the approach I'd take to reconcile them with scientific knowledge.

[raducu]

Or some decaying that reduced lifespan and made marrying your close relatives not ok :)

But I don't think there's any point trying to reconcile the naratives.

[tomrod]

Yeah... we're getting to angels on a head of a pin dancing here.

My fundamental point is that a broken clock isn't predictive, even when it happens to be right.

[neither_color]

Is it also not possible that they were counting lunar cycles, seasons, or something else as years? In the case of lunar cycles 969 would be about 80.