[neaden]

There is the idea in the Bible that in the time before the flood people were somehow greater. They were bigger and lived longer. Here is a quote from Noah's genealogy for instance from the New Revised Standard Version, Genesis chapter 5.

"21 When Enoch had lived sixty-five years, he became the father of Methuselah. 22 Enoch walked with God after the birth of Methuselah three hundred years, and had other sons and daughters. 23 Thus all the days of Enoch were three hundred sixty-five years. 24 Enoch walked with God; then he was no more, because God took him. 25 When Methuselah had lived one hundred eighty-seven years, he became the father of Lamech. 26 Methuselah lived after the birth of Lamech seven hundred eighty-two years, and had other sons and daughters. 27 Thus all the days of Methuselah were nine hundred sixty-nine years; and he died."

After the flood things changed, and you don't have these incredibly long lived people anymore.

[lurquer]

People seem to forget the story states it never rained before the flood and that a mist covered everything. Indeed, there wasn’t enough direct sunlight for a Rainbow until the flood.

Regardless of whether it’s true or not, the story is describing a different type of earth; one covered with dense clouds that all precipitated at once, flooding the world and, ever since, exposing everything to UV radiation which obviously would have an enormous deleterious impact on lifespans.