Biblical lifespans revisited

I did a bit more research into the Bible lifespan thing and found this on BibleStudy.org:

There are many factors that could account for the lowering of the life spans after the flood. The Bible states that the flood would not only destroy the land dwelling air breathing animals but it would also destroy the earth. (Gen. 6:13; 9:11)
After the flood the earth was completely different than the earth before. There were widespread global differences. These would include changes in the climate, composition of the atmosphere, hydrologic cycle, geologic features, cosmic radiation reaching the earth, ozone concentration, ultra violet light, background radiation, genetics, diet, and a host of other subtle and/or profound chemical and physiological changes. These changes caused a rapid decline of the longevity of post flood humanity.

I've also come across some interesting (and strange) ideas such as men crossed with aliens who had long life spans, the earth's magnetic field was more stable back then, the lifespan of one "person" was actually the sum of lifespans of their descendents, God decided we were acting too badly to live that long, etc. Now, I'm not questioning the truth of the Bible, for anyone who may come to that conclusion, just wondering how and why things happened the way they did. It's a normal human trait to explore and investigate the unknown, and many things in the Bible are not explained in detail.

ApologeticsPress.org states that:

We know—scientifically—that: (1) aging “is a metabolic process”? (2) the process is indeed controlled by a “pre-programmed genetic limit”? and (3) “human bones continue to fuse together right up to advanced old age.” If people at that distant point in human history possessed slower metabolism rates (an extremely reasonable suggestion, considering the condition of the world in which they were living at the time—see Dillow, 1981), and if the human genome contained genes for greater longevity, then the patriarchs could have lived to vast old ages, and the slower metabolisms would result in fossils that appeared to have formed from much younger individuals. In short, scientists actually could be in possession of—could be staring at in their laboratories—bones from people who had lived to ripe old ages, and they never would know it! Thus, the allegation that “most bones of ancient men turn out to be twenty or thirty years of age and none has been found older than eighty years old” (to use Clayton’s exact words) means absolutely nothing in light of the actual scientific facts concerning human aging.

To elaborate on the genetics issue:

If this suggestion has merit as the major (if not the sole) cause of great pre-Flood ages, then the obvious question is how some of these longevity genes were lost. The human population went through a severe genetic bottleneck at the time of the Flood—only eight individuals. The phenomenon of “genetic drift” is well known to be able to account for “random,” selectively neutral changes in gene frequencies which may be quite rapid. Also, loss of genes is far more likely in a small population....
It is also likely (if not more so) that genes coding for lesser longevity arose by mutational degeneration, with their frequency of possession rising as time passed. At the moment, too little is known of the exact mechanics of the way in which cells are programmed to die in order to offer more specific suggestions (1994, 8[2]:139-140, emp. added, parenthetical comments in orig.)

I would suggest that you read the entire article to get the whole gist of it. It seemed, however, that they come down really hard on scientific investigations into Biblical history, like it's not right to investigate anything the Bible says in a scientific manner. People are just supposed to accept it all and be quiet about it. I just don't agree. I DO believe the Bible as the inspired word of God, but I see nothing wrong with questioning how things happened the way they did. I think God meant for us to investigate and explore the world around us, or He wouldn't have given us the minds we have. I also think that God meant for us NOT to know everything, so everything known to HIM is not in the Bible--could you imagine how BIG that Bible would be? No one could ever read through that one :) But I don't think he minds if we try to figure it out--just if we doubt it's truth. He probably laughs at us sometimes, saying, "They'll never understand THAT one!" I know some are just supernatural, God-powered events that have NO scientific explanation, but some things, like the ages of the patriarchs, could possibly have scientific explanations behind them, and it's interesting to try to figure it out.

Here's another hot topic for some debate: Did dinosaurs live alongside man? Most scientific theories say otherwise. What are YOUR thoughts about that?