THE MYSTERY OF THE HELIX

The mysteries of life in the DNA helix have grabbed my attention.


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.

35 thoughts on “THE MYSTERY OF THE HELIX

        • We both got our results, but we didn’t get any information about the results. Nothing, not even a page of general information. Which for me was very frustrating. BUT it turns out there are genetic research programs into which you can plug your information and get more information. It depends on what you are looking for, of course, but within the limits of the tests we took. I think I’ve gotten as much information as I can extract. More will come. People are building tools everyday. And they are free.

          I’ve got “Ancient Ancestry” and “Ancient Calculator” apps to help figure out where we fall in the “ancient people” categories. This stuff is really interesting, although most of it has nothing to do with us. It’s just interesting.

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  1. It’s all a bit complicated for me. My oldest son is my dad completely and I passed colour blind onto my youngest son from my father. The Swiss are a complete mixture so who knows what is included.

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  2. You might find some valuable info to thelp with your understanding if you look up ‘Epigenetics’.

    Basically our genes can have ‘active’ and ‘silent’ components that even though they are the same DNA as our parents/grandparents etc may not have the same parts active and silent when determining our characteristics from our ‘common’ genes.

    You Grandmother may have had an active segment of DNA that in you became silent which then became active again on one or all of your children. It has been suggested this is the mechanism via which some traits seem to ‘skip’ a generation. Whether or not this activity/silence is able to be altered during our own lifetime is still being investigated – it may be possible to control some changes by relatively simple means giving us some kind of control over all sorts of aspects of our body/character through epigenetic moderation.

    Your right – it is fascinating. 🙂

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    • From what I have read, it isn’t that simple. We do not inherit ALL the DNA from our parents. We actually inherit more from one side then another and within each bunch of stuff, there is stuff that is inherited from previous generations. The “silent” “active” thing is more time-based. You don’t look the same way at 3 and at 30 or 50 or 70. Different parts of your DNA “kick in” so you not only seem to change, you really DO change.

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    • It is really interesting. Since I never met any of my grandparents, I have no idea if I remember any of them. I don’t even have any pictures of the.

      Tracing family has been kind of pointless. We’ve both found people who are no doubt family, but no fewer than 3 generations back, so at the least, second or third or fourth cousins. I don’t see how getting in touch with them would benefit any of us particularly. I’m more interested in where we all came from originally and how we managed to get to where we are now. The paths of the clans as they made their way out of the African rift into Europe and Asia and Africa. How we developed languages. What about all those Steppe Men with their copper hammers and horses? That must have been really hot technology 7,000 years ago!

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      • I feel the same about genealogy. Orgins interest me far more than lost and distant family branches even though I am told we have some illustrious names… the only way it would be interesting is finding out what side of the blanket my branch came from 😉

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        • For me, unless they are leaving me the castle and family fortune, kind of hard to get really excited. I suppose if they happen to live in some utterly mystical location where I might visit … but pretty much everyone I look up lives in Florida or New Jersey. Not inspiring. Garry was deeply uninspired too. Really, what do you do with a fifth cousin four times removed? And what IS that removal all about?

          What interests me is how MANY relatives we have. Over the past seven or eight generations, we have THOUSANDS of cousins and aunts and uncles. Everywhere, all over the world.

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          • I agree. I had occasion to do a bit of research a few years ago and even within living memory, the family structure spreads so wide. I knew most of my great-grandparents…and, being born when Victoria was queen, most had many siblings…who married people from large families and themselves had large families… who also had children…Even within a few generations, you are looking at hundreds…
            I don’t think you have to go all that far back to realise we are all related somewhere on the human family tree.

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  3. I still think the “seeing a resemblance” thing can be more the brain trying to make a match than actual physical resemblance. Like if you showed me a picture of two men thirty years apart and told me they were father/son… even if they looked nothing alike, my mind would tell me there HAS to be some resemblance there, and would keep looking at each face until something jumped out at me as similar.

    That said, I still have a personal story that contradicts my belief. When I started working at Mecca 19 years ago, one of the ladies who was working there at the time grew up on the same street as my Dad when they were kids, and she came up to me not really having a clue who I was and asked if I was Bill Brown’s son. I have still never noticed any resemblance between me and my Dad’s apperance when we were both about 20, but so many others have mentioned we looked so much alike as young men that there must be something to it…

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    • I used to think that too, but actually, it’s not true. We really DO get bundles of DNA and not only from our parents, but from other linked family member. It appears almost random, though I suspect it isn’t nearly as random as we think it is. There is undoubtedly some method to the madness — we just don’t know what it is. Yet.

      We inherit appearance. We don’t inherit it equally from both parents or all the children of one set of parents would look alike — which they don’t. We inherit lots of stuff from grandparents and their siblings and even their parents so that ‘Wow, you look JUST like grandma” can be an actual fact. Because maybe you just got that big lump of DNA from granny.

      DNA doesn’t hit us all at once. We’d never be babies, you know? We’d get our entire inheritance the day we were born … even thinking about it is weird. So we do look different at different times. We don’t look 40 when we are three and we don’t look 20 when we are 70. I think that’s probably just as well!

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  4. Another fascinating post, Marilyn! Our youngest daughter looks just like my maternal grandmother and has since around the age of twelve, while our oldest daughter sometimes resembles ancestors of my family and others looks very much like relatives of Dan’s. Me? I look like my Mom and have since about age twelve. Oh, that marvelous DNA conundrum just keeps us guessing. 🙂

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    • And I love how they change, too. Owen was a duplicate of his father until he hit school age and then his face changed and suddenly, he was little me. The blond hair went away, the hooked nose showed up. But he has his father’s hairline and domed forehead. We all get little pieces of everyone, hopefully not in too weird a location.

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  5. It made sense to me, but I worked (in a clerical capacity but you still learn LOADS if you’re paying attention) in Clinical Genetics for a majority of my adult life. And you’ve explained nicely why unexpected things show up at different times…I have one brother who was the spitting image of my father, and had a son who was the spitting image of brother at 3, who now looks like an unknown person (my brother’s wife was adopted and knows next to nothing of her ancestry). This same brother was 6’1 or 6’2 in his prime and always really lean (like my father). Myself and my other sibling took after my mother’s side of things, and these days I look in the mirror and get a shock because often she’s staring back out at me. My other sibling was bald at 25 years of age (well thinning to the point he finally just shaved it all off), is ‘short’ 5″10 (men are so weird about height sometimes), and looks a great deal like my maternal grandfather (apparently). First brother had four boys and 2 girls (one daughter died as a newborn) and the other other brother had four girls. All the girls are very tall – the shortest is probably 5′ 8″ and the tallest is 6′ 2″. My other brother’s sons are two tall, 6’4 and 6’2 (he’s 16, he’ll get bigger I’m betting) and one short (the short one takes after my mother’s family) at 5′ 10 (as I say men are weird about their height sometimes) and their daughter is 5′ 6″ (like I was at her age). My sister in law (of the boys) is 5′ 1″. My other sister in law is 5′ 6 ish… and only one daughter of the four takes after her in looks, the rest are dead ringers for my brother. So me? I find all this stuff simply FASCINATING and hope you share more as you learn more.

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    • I’m finding it fascinating too. It explains so much that has always been so muddled — why my husband at 5’6″ has a younger brother over 6 feet … and a tall father, but a short mother. And who does he look like? He used to look a lot like Mom, but these days, he bears a remarkable similarity to his father. The changes in our appearance are one of the things that are hard to explain to people. Just because you USED to look like Mom, doesn’t mean you won’t be a dead-ringer for Aunt Sara — on the other side of the family — by the time you hit age 50 … or like you father when you are turning 70. For a while, I was a duplicate of my mother, but I’m changing again. I wonder who I will look like next!

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  6. Marilyn those are million dollar questions. One thing that came to mind was Gregor Johann Mendel (1822-1884) and his peas. He was one of the early researchers in genetics and tried to determine how certain traits were passed on to the next generation.
    Leslie

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  7. Marilyn, this was the best article about our DNA that I have EVER read. I could understand it. Clear and concise. Thank you! I hope you keep sharing what you learn as you go. Book worthy for people who want to know or teach their children about. Schools could use them!
    Glad you have the brains to figure it out for people like me! 🙂

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    • Thank you. I spent more than 30 years writing documentation, so it’s probably the thing I do best and most easily. I was always saddened at how awful most school books are. If they would let people who know how to write well put the books together, kids might even learn something. Which would be a great trend in our schools!

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      • It would be. You made it interesting to read AND easy to comprehend. It made me want to read it. Just think if school texts would do the same? You would find students eager to learn!

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