Ever since I dove into the science of DNA — as opposed to “I’m looking for my family,” I’ve been fascinated about how it works.
I always figured we got half our “stuff” from mom, the other half from dad. How it mixed up was like the big bag of goodies on Santa’s back. You got your portion — and who you looked like? Well … it might depend on the day, year, light … and all of that.
I was right. But I wasn’t entirely right because there is a good deal more to it than that. As a start, we only get a 50-50 split between both parents in theory. In actuality, we may get much more from one parent than the other — a lot more DNA from one parent than the other. We me get even more from our grandparents, who in theory only contribute 25% to our make up but this stuff doesn’t come in neat, divisible piles.
“Y0u look exactly like your grandmother” isn’t just something people say. You may really look exactly like your grandmother because all those alleles that make you look like you do came from her batch of DNA. It’s why siblings may look very different from each other — unless they are twins, of course. It’s why short little me has a 6 foot 4 inch son and he has a 5 foot tall daughter.
Tall brother, short me — and very short sister. Blond brother and sister. Dark-haired me. Green-eyed siblings and me with the big brown eyes. Tone-deaf brother (like father). Musical mother, sister and me. My son looked like a photocopy of his father when he was a toddler. By the time he hit his teens, he was a dead-ringer for me. Except right now, he looks remarkably like his father again … unless you see him from the side, in which case — it’s me again.
How can that be? How can we look like very different people at different times of our lives or for that matter, like two very different people at the same time?
It’s because all your DNA doesn’t kick in at the same time. That’s why blond babies end up with brown hair and dark-haired people end up with white hair. You quite probably did look like dad when you were three, but you are the spitting image of your mother by the time you’re forty and who know who you look like in old age? Different parts of the big helix takes charge during different life stages. I had wildly kinky-curly hair as a girl. Which went straight by the time I was seventeen and has stayed that way.
The same thing happened to my granddaughter. She casually said “Oh, I don’t have to straighten it anymore. It’s just went straight.” Right on time, too. It’s a late teens thing, apparently. Meanwhile, before I was 30, my hair was half gray and white by the time I was 50. Now, it’s getting a little browner again. Different DNA kicks in and things change.
If that’s not a mystery, what is?
Even with all of the things we’ve learned about DNA over the past couple of decades, there’s so much more we don’t know. Like … how does personality attach to the “how we look” segments? I always looked like my father by coloring, though the rest of my face looks more like mom. My brother looked just like my mother until one day he looked exactly like his father.
Do things like criminality, high intelligence, patience, restlessness, high energy … do these come as part and parcel of our appearance? Are they separate? Is there such a thing as “looks like a good guy? or looks like a bad guy?” Surely some portion of our traits come out of the helix, but the rest must be at least affected by environment, right? We have long since learned that environment is not the only thing that turns us into fully formed people and more than half of us is hooked onto our DNA but that can’t be all of it. So, how much of how we relate to our DNA is based on the lives we live?
So many questions and not nearly enough answers. For the time being, I’m locked into trying to figure out how this works. Garry and I have both “discovered” family … but it’s so many generations back — at least 4 — that whoever they are, they aren’t terribly relevant to ourselves right now.
Unless they have a huge heaps of money are coincidentally looking for nice people to whom they can give it. If that’s so, please … over here! We could use a little help!
I’m sorry if this sounds too complicated, but it isn’t. It’s really an explanation of why we don’t necessarily look like a combination of mom and dad and might instead look like Uncle Jim or Granny. Why your brother looks nothing like you and your son is a full head and a half taller than you, but your granddaughter is a lot shorter.
DNA isn’t evenly or neatly divided. We get all the stuff from parents and grandparents and great-grandparents and what we look like — and act like — can be a pretty wild combination of all the people who are part of our ancestry. All of them … all the way back to Africa, from which we all emerged.