When God first created the Earth, Adam and Eve were meant to be immortal, but because of sin, they began to have a life span. The life span which became normal at that time was about 900 years. However, as sin increased even more, the human life span decreased, because God allowed certain enviromental changes to occur which shortened the life span. For instance, the magnetic field decreased, allowing parasites which had once been incapable of entering the body to do so. Eventually, the human life span had been decreased to about 70 years. Well, enviromental changes which effect humans also effect reptiles as well as other animals. And, reptiles grow as long as they are alive. A komodo dragon can live about 70 years and grow to be about 7 feet long. If the human life span decreased from 900 to 70 years, that is a decrease of 13 times. If a komodo dragon has experienced that same effect upon its life span, it would have been about 91 feet long back when humans lived for 900+ years, since it would have continued to grow for its whole lifespan. What do you call a 91 foot lizard? A dinosaur!!!