If there is no purpose for us to fulfill--if we are indeed here because the survivors of hecatomb after hecatomb (I love Steven Jay Gould) then we must question what all these genetic studies tell us. You know what I mean: the genetic studies telling us that we're "designed" to store fat, destined to get cancer, preordained to suffer mental illness, headed straight for addiction--that the few genetic diseases that we understand (sickle cell, cystic fibrosis) arose as adaptations to a new world order.
I don't mean to question the studies themselves. The studies are, more or less, quite sound: the melanocortin system's role in obesity is currently being teased out; single nucleotide polymorphisms of the MC receptor are believed to be responsible for the abnormal reward signals that lead to overeating. Nobody doubts the role of p53 in cancer--or any of the myriad pro-apoptotic genes. Epigenetics apparently has a bigger role in mental illness than genetics, strictly speaking, but there is definitely a genetic component to mental illness. The science is sound--genes, when they go wrong, definitely cause diseases.
But do they necessarily define who we are?
If you follow the "no purpose" argument to the logical conclusion, then the answer is yes: genes select themselves for the sole purpose of being passed down. They don't really care whether or not we survive the passing thereof. That's why otherwise nice men become assholes the moment a busty bleached blond bimbo walks into the room, why women feel obligated to make peace between warring factions, etc.
Or so the argument goes: genetics provides limitations within which an individual can succeed. Certain environments, certain societies, place certain emphases on which genes are prized, and these get propagated. So free will is really a myth.
Or is it?
You'll notice that, throughout this entire series, I've done my darndest not to justify leaning towards one side or the other (and I stated my bias in the beginning, so if I didn't succeed it wasn't for a lack of effort). The reason for this is twofold. First, if you're reading this, odds are you already have a good idea of where you stand on the whole evolution/creationism debacle and anything I write trying to persuade you that creationism isn't a science is just a waste of my time. Secondly, the goal of this series was never outright damnation of either side--to do that would run counter to my personal belief in God--but to ask why this debate is happening at all. Have I missed something? Undoubtedly I have. So please, comment, and let me know what your thoughts are on this whole thing.