the people back towards adam and eves day were closer to prefection, and also consider this..

If the earth was a paradice would not our oxygen suply be alot higher than today? Oxygen is anti bacteria and with such a oxygen rich envryoment I do not think it impossable to live a life of 900. Science today has yet to explain why we grow old and what causes our cells to start sucideing.

In all reality our bodys should run and renew them selfs. After noah's day most vegation would of been wiped out cept a few higher places. So the earth would be working differntly, because befor noah's day it didn't rain, a mist went up from the earth to water all, Thats why no one belived him it was going to rain and flood everything.

With all the water added to our earth the atmisphear must of dramaticly changed.

(sorry for spelling, Hope you get my points)