Have you ever wondered why humans must eat fruit to stay alive, but dogs, cats, cows, squirrels and other mammals don’t? It’s because all mammals need Vitamin C to survive, but simians (including humans) are among the very few mammals that cannot synthesize Vitamin C from their diets. Why? Because humans (along with other apes, monkeys, guinea pigs, fruit-eating bats, and a few other species), carry a genetic defect that disrupts the Vitamin C production process.
Here’s the interesting part. The vast majority of animals and plants are able to synthesize their own Vitamin C through a sequence of four enzyme-driven steps, which convert glucose to Vitamin C. Human metabolism can, and does, perform the first three of these steps, but we have lost the ability to perform the fourth, because our gene that would produce the required fourth enzyme contains a defect and no longer functions. Consequently, we cannot use the resulting proteins to synthesize Vitamin C: our bodies break the proteins back down and reabsorb them.
Why is this important? Well, the Bible tells us that the Garden of Eden contained fruit trees. Fruit trees would have been unnecessary if God had created Adam with a properly functioning gene to synthesize Vitamin C. Why did God not give Adam (whom God supposedly created in His own image) the properly functioning gene that He gave to virtually all other mammals? Also, why did God give Adam the genes for the other three enzyme-driven steps, even though they would be useless without the fourth? Doesn’t it seem…un-godlike…for an infallible God to have designed a “perfect” human who not only had a defective, non-functional gene, but also several functioning, useless ones?
Of course, evolutionary theory easily explains this phenomenon: millions of years ago, our ancestors once had four working genes, but a genetic mutation occurred sometime in our lineage that has been passed down through the subsequent generations. Fortunately for our ancestors (and us), this mutation was not fatal, because our ancestors were able to get Vitamin C from their diet, as we still must do today. True, fruit is not our only source of Vitamin C, but our rare inability to synthesize Vitamin C makes me wonder where the supporters of so-called “intelligent design” get their absurd belief that our design is intelligent, especially when their own holy book suggests that their infallible god created us, from the beginning, with a very obvious genetic defect.
projektleiterin wrote, "…would it be really necessary to use a bird to check out if the flood had receded and land was visible again?"
Actually, yes. For as long as humans have been sailing the oceans, sailors have been following birds to find dry land. Not captive birds, of course, but wild ones. In the days before accurate maps and precise navigation, sailors risked sailing past even very large islands on their trans-oceanic trips, but they noticed that birds (which would fly beyond the visible horizon of dry land) created a much larger effective radius around islands, thus making a much bigger target for the sailors to hit. So, they would always look for birds, whose existence would indicate proximity to land and whose flight path would help guide them to it.