No, the sleep thing was a joke. You need a clue as well as an education and intelligence.<quoted text>
LMAO! where did you get that theory about giraffes? Darwin from the 1800? LOL.
How does our DNA change? You have an explanation? or sleepiness is your excuse?
What theory? We have the fossils, it's in stone actually.
You still don't even know how and why DNA changes, you have a ton of studying to do. Well, here's the basics, the DNA is a LOT of chemicals bound together in chains. These very long chains are tiny, they get bunched up into chromosomes. Copying chains that long in chemical processes, the way our cells work, will lead to inevitable "mistakes," quotes because they are not detrimental, most times. These mistakes account for variations in cosmetic appearances between the offspring and parent, such as hair color, eye color, etc., and somethings a new physiological trait or loss of one. The organism passes these changes on if it survives, then the real test of the new traits begin, if the population becomes more successful because of the trait, since the successful organisms will be more likely to breed that trait will quickly become more common. But you won't see the trait most times, it may just be a small bump on the shoulder, or a single cell change in the eye, or a new mucus membrane over a sensitive organ ... but it's there, there's always something different, always something new. If it proves detrimental, the organism(s) die(s) before the trait spreads to most of the population. There, over simplified, but genetics 101.