-People's lifespans are reduced by around half after the Flood (avg 860 years --> avg 480 years).
-People's lifespans are reduced by around half again after the Tower of Babel (avg 480 years --> 210 years).
-Noah and his son Shem are still living when Abraham is born!
Shem outlives nearly all of his descendants (listed in Gen 11) up to the time of Abraham. The only exception was Eber (possibly where the term "Hebrew" originated?). Shem was living during the time of Abraham and Isaac. Perhaps there is some basis for the story of Utnapishtim (whose name means "he found life").