Brian,
Yes, I believe the world is only about 6,000-10,000 years old. No, I am not saying that the species now are the only one's there have ever been. Before the Great Flood, I'm sure there were many species including dinosaurs and many other plants and insects. The 65 millions years date is set most likely by carbon dating, wouldn't bet my life on that since it's been proven wrong in many occations.
Yes, you do in fact grow from the day you are born, but you are dying at the same time. The reason Jesus heals is because it is supernatural something the human mind cannot comprehend. The closed system "anti-entropic" effects you're talking about is only delayed entropy. If you put a human being in a near perfect enviroment, with near perfect food, and near perfect training sure they'd probably live a little longer. But, not that much. They're still gonna die.
The man's arm doesn't "adapt" it reacts to an external stimulus the 40 pound weight. The muscle tears filling with blood enlarging it. Just like you create more blood in your bone marrow when you lose blood, you build more muscle when you create the need for more muscle, such as lifting weights. But, the more time goes by the harder that same man will have to work to maintain the same amount muscle as before because...you guessed it entropy 
. Enjoyed your post though .
-Will
