On DNA and Freedom of Choice
How many of your body decisions really belong to you?
DNA is why we're all alive, and I don't just mean humans. Everything that isn't a virus contains DNA (and scientists aren't even sure about that), and it's how every living creature on the planet reproduces themselves. Although it takes different lengths of time for cells to die, eventually they will all need to be replaced, which is partly where DNA comes into play. If you remember mitosis from high school bio, your cells split and each new cell contains copies of the parent cells. This allows your liver to keep processing martinis, your mouth to keep producing saliva, your muscles to keep getting massive. Your DNA is six feet of genetic material impossibly wrapped up into the nucleus of each one of nearly all of your forty trillion cells. If scientist estimations are correct and we were able to unravel all of our DNA and line it up end to end, it would stretch to Pluto and back. And yet, it doesn't have all the say in what happens in your body.
We don't actually know what things we're in charge of.
You've heard the debate about nature vs. nurture, and it's a debate for a reason. We know that our genetics have some control: Two recessive copies of the cystic fibrosis CFTR gene mutation and the child will have cystic fibrosis. No amount of nurture can correct the mutated protein.
But many genetic mutations seem like they should cause a problem, yet they don't. Blue eyes and red hair are mutations (Except Emma Stone who is the opposite of mutated). Pink grapefruits literally arrived one day, confusing the hell out of the famers who found them. And these aren't limited events. It turns out that even though we think of our DNA as producing identical copies for all of our lives, our DNA is all over the place. One study of normal blood from 241 normal-presenting adults found 163 mutations floating around. DNA replication is like when your kid is jumping off the playground into your arms and even though there's only one way he can possibly go, he does a 360 swan dive backwards over your shoulder and onto his face. It's bananas.
That's the nature part. This is the nuture part. Nutrition, exercise, stress, healthcare interface, family dynamics, socioeconomic status, education, race, gender, sleep, climate, social circles, and whether you eat Pop Tarts circle-style or typewriter-style (hint: circle or stop reading my blog), can all have lifelong impacts on how your genes express themselves. But even then you're not married to your past, because if you exercised only your left leg today, that leg would have different genetic activity than the right one. The bottom line: We don't actually know what things we're in charge of. Only about 20% of our collective American health can be attributed to genetics.
Your limits have not been set for you.
Even with serious diseases and health concerns, the number of certainties is nearly zero. In studies of schizophrenia in fraternal twins, there are only 10-15% of cases where both twins develop the condition. In identical twins, you'd think it would be 100%, right? It is not. Even in identical twins, where two people ostensibly share everything down to the molecular level, the rate of both twins having schizophrenia is only about 50%. What happens with the other half? That's yet to be answered, but we know it's more than just DNA. And if those unknown forces can repel schizophrenia, they're more than enough to repel whatever demons you're working on.
Can we straighten our curved spines? Is paralysis final? Are we genetically predisposed to being fat? Will cancer kill me? Science has no idea. We can only try and find out, and this is called hope. So while understanding DNA helps us accept things the way they are, it also helps us dream of the way things could be. One thing we are certain of: the limits of your body have not yet been seen, because no one like you has ever lived before. The way it happened to someone in the past can help us understand patterns, but not inevitabilities.
One of my central tenets of health is that if you want to change, you can. I'm not saying that nothing is permanent. What I'm saying is that we don't know if any given thing is permanent. No matter what your DNA says, your limits have not been--and will not be--set for you. You set them where you want them.