Henry VII of England - Haplogroup I1 is the likely subclade of the Tudor Dynasty

F1 generation =100%: F2 generation = 50%: F3 generation = 25% (we are here in terms of distance of 108 years from the Mills/Tudor blood addition 8/of 24) F4= 12 .5% F5 =6.25% Now if there were someone who came along with another dose of TUDOR DNA it would move the percentages upward instead of downward....That's what i see happening....The facial and other features happen to be expressing in this manner which you seem to want to deny....nevertheless it is happening. IM saying that Perrott 1600 has 100% Tudor Y and all subsequent males of that line including John Rice 1624 and the descendents of Captain John Rice the TRADER on the James River would also have to test out with the same DNA. I really would like to move in the direction outlined to see if we can identify the Polands DNA Y data compared to John Rice 1624....If they are the Same Haplogroup and Y site identical or one step difference on 1 site then we have the indirect proof of my theory based on a Mendelian idea: think of the faces as colors....we are in the 3 generation and showing 25% as expected. YES?

Dale, it's hard to follow the exact details of your descent but I see places where you say things like, "Thomas 1570 received XY chromosome from Father and Mother desended from Henry Tudor:.

I think that you mean Thomas was descended from Henry Tudor on both sides, not that he literally had both x and y chromosomes from Henry Tudor.

It's your family tradition that he had the y chromosome of the Tudors, but of course his x chromosome would be an unknown. Thomas got his x chromosome from his mother. She had two x chromosomes, so the one Thomas got could have come from his mother's father or from his mother's mother.

To complicate things, segments of the x chromosome sometimes cross over from one to the other. So, Thomas' x chromosome could have been a hybrid of an x from each of his mother's parents.

In short, Thomas' actual x chromosome will always be a complete unknown unless you exhume his body and there is enough un-degraded DNA for a test. Doing that wouldn't get you anywhere, though. Because of the cross-over factor, it is highly unlikely that Thomas' x chromosome would match anyone living today.

Just so we're clear, I hope you also understand that there would never be any x chromosome that could be called a Tudor x chromosome. There are just all the different x chromosomes inherited by different members of the Tudor family.

In the end, it doesn't matter for anything except for y-DNA triangulation. There are no physical characteristics on either the x or y chromosomes, so they won't determine whether someone looks like a particular ancestor. And, because there is no amplification effect, it doesn't matter how many cousin marriages there are in someone's ancestry.

I want to be sure we're clear about x chromosome inheritance, so I'll illustrate with a personal story.

My mother, my half-sister, my nephew, and I have all had autosomal DNA tests, so I know our x chromosomes.

My mother, being a woman, has two x chromosomes, one from her father and one from her mother.

Being a man, I got my x chromosome from my mother and my y chromosome from my father. My x chromosome exactly matches one of my mother's x chromosomes. Of course. It didn't have to match exactly. My x could have been a blend of my mother's two x chromosomes. Because my x matches my mother exactly, I know that by definition it also has to match exactly an x-chromosome she inherited from either her father or her mother, but I don't know which.

My half-sister, being a woman, got an x from her father and an x from our mother. One of her x chromosomes matches mine exactly. So, I know that she also had no cross-over, and I know that she got the same x from our mother that I got. I still don't know which of our mother's parents it came from. I also know that her other x chromosome, which came from her from her father, must either match one of her father's parents (or be a blend). He hasn't been tested, and neither of his parents were tested during their lives, so that's a dead end.

My nephew, being a boy, got his y chromosome from his father and he got one of my sister's x chromosomes. He also happens to match his mother, my mother, and me exactly. So, no cross-over, and I know that his x is the same one that came from one of my mother's parents. I still don't know which one. If his x hadn't matched me and my mother, then it would match my sister's other x (or be a blend) and we would know that he got it from my sister's father.

If you take the time to follow all that, you'll see how simple it is but also how hard to predict the path of an x chromosome.

This isn't the end of the story, though. My mother's parents have very different ancestries. Her father's parents were Swedish immigrants. Her mother's parents were both from old line American colonial (English & Scottish families).

So, a national origins analysis can pin it down a bit better. The x-chromosome that all of us share is about 2/3 Scandinavian and 1/3 generic Northern European.

That means we're probably looking at the x-chromosome of my mother's father. And, because he was a man and only had one x-chromosome, it would have been one of the two x-chromosomes of my mother's father's mother.

Of course, we can't be certain there was no cross-over. Some segments of this x could be from my mother's mother, and ultimately from either one or both of my grandmother's parents. The only thing we know for certain is that no portion of this particular x came from my dad, from my sister's dad, from my sister's husband, or from my mother's father's father.

Dale,

The math is pretty simple. I invite you to do it yourself, so you can check what I'm saying.

Count back the number of generations between you and one of the Tudors. Say, Owen Tudor. Call that N. You can figure out how many ancestors you have in that generation by taking 2 to the Nth power. Call that X. Then, figure out how much DNA (roughly) you inherited from that generation by taking 100 divided by X.

No matter how much you try to minimize the effect, you'll see pretty quickly that however many generations there are between you and Owen Tudor, you ended up with a tiny, tiny fraction of his DNA.

You can do the same thing with Thomas. Count the generations between Thomas and Owen. Same calculation. If Thomas has four Tudor descents, go ahead and multiply by four.

And, so the same thing between you and Thomas. Count the generations, etc.

No matter how you work the numbers one thing will stand out -- your genetic inheritance from Owen is so tiny that it can't account for someone in your immediate family looking like him.

No matter how politely I try to phrase it, the argument you're making is just flat impossible. To anyone who understands DNA, you're not proving anything. I want you to understand that I "don't have a horse in this race" (as we say). I don't gain anything or lose anything either way. My sincere hope is that we can get you on a track that will really help you prove (or disprove) your connection.

It doesn't matter if Owen Tudor is my DNA contributor....because as we all know that's all that can be in the blood of males of the Y Chromosome descendents of Henry....who is 14 generations....his X contribution declines by 1/2 each generation....I explained that did I not? But the Y portion remains constant over time. My example is for my Ancestor at 108 years who traces back to the Tudors via Gardiner contribuiting a small amount of new X to her children.....WE are in generation 3 from her and show about a 25% distribution of effects per Mendal....You convinced me....I have zero.....or I have 100% Y Tudor and a diminishing amount X Tudor....The frequency which comes up for recombination was last refresed slightly 108 years ago........Every Male is going to carry a lot of unexpressed Tudor Y and a little bit less of Tudor X since 1570 when Thomas ap Rice got the full dose on both X and Y from both his parents....Therefore....it's ZERO + a little Female X dose 108 years ago or it's 100% Y+ a little extra X from Rebecca Mills 108 years....which upped the expression of features which are now showing the decline of features at 25%......8 of 24 the last 24 persons born....That's what you explained to me and How I understand mendal.....Perrott = 100% Y + 50%X divided by his mothers contribution of her X His son John Rice 1624 by Tamzin would be 100% Y +25%X divided by Tamzin's X for recombination then we are down to the sons Samuel and Samuel then Edward and Rebecca Mills.....My contention is that we are the people my FAther indicated we were and I side with that because of the Mendalian odds or chances of a fluke is impossible to calculate with this pedigree....we will have it as a Proof if the Poland males = John Rice 1624 of Dedham as I1 and Y match. I can logically and scientifically believe that. That is a fully reasoned conclusion.

Beatrice Tudor Carries XX one of which is from Owen Tudor Daughter Helen she gives that same X to Wm. Henry 1521 along with Henry's X= X2+ YTudor which then combines with non Tudor X+ Y non Tudor = John Rice II 1540. He is CarryingXTudor 2X Tudor divided by nonX tudor mother and 100% Y Tudor which combines with Catherine Perrott's Tudor X +Mary Berkly X performing the math is beyond my ability at this point but you see the doubling of genertic material in son Thomas? His Y remains either Zero or it's 100% Y Tudor.....his X is 1/2 Tudor but declines by 50% in each succeeding generation....That's what I want to say to you....3 doses of Tudor X and one Y Tudor going forward....andy phenotypes that display as features inherited have that scaffolding to attatch, and the Tudor DNA seems to attract the other Tudor DNA....the 5 women inbetween me and the last dose of Tudor 108 years ago are related to the Churchill/Stewarts which goes back to Margaret Tudor to the Stewart lines.....It's right there in front of us....Tudor on top of tudor divided by the women along the way but generations of Stewart and Tudor are refreshing this lineage in my great grandmother great, great grandmother Mills....We see the faces of all these people as a result of mendallian distributions recombining with the BASE line Tudor 3X at Thomas ap Rice 1570.

Still not quite right. You are using x in a way that implies it is a shorthand for the entire maternal inheritance. It's not.

Humans have 46 chromosomes, 23 from the mother and 23 from the father. That's your autosomal DNA. The x is one chromosome, and the y is another.

The y never combines. It just gets passed down intact. The other chromosomes, including the x, also just get passed down, but at each generation only one of the two copies gets passed along to the baby. For everything except the y, segments can cross over. In other words, the Chromosome #3 (or the x, or whatever) that gets passed down might be an exact copy, or it might have fragments from the other copy.

So, it doesn't really make sense to talk about 100% y or 0% y. Your y chromosome is either the Tudor y-chromosome or it's not. There is also no such thing as an expressed or unexpressed y. If someone has a y chromosome it's always expressed -- the baby is male.

And, it doesn't make sense to talk about percentages of x. One copy of everything except the y is just getting passed down, either intact or blended a bit by crossover.

Also, we should be clear that the number of years doesn't count. The only thing that counts is the number of generations. In other words, the number of times a parent transmits half their chromosomes to a new baby.

So, in your example it's misleading to think in terms that "Thomas ap Rice got the full dose on both X and Y from both his parents". No. What he got was his father's unchanged y, and a random assortment of 22 other chromosomes from his father, plus an x from his mother, and a random assortment of 22 other chromosomes from his mother.

So, if Thomas was five generations down in the male line from Owen Tudor, then he got Owen's unchanged y-chromosome, plus a tiny fraction (100 divided by 2 to the 5th power) of Owen's other chromosomes. That works out to 3.125%. This number is just an average, based on probabilities. In fact, Thomas could have gotten 0% from Owen. There's no way to know or calculate whether Thomas specifically got any of Owen's x chromosome.

And, if you are five generations down in the male line from Owen, then you got Owen's unchanged y-chromosome, plus 3.125% of his other chromosomes. Again, this number is just an average. You could have gotten 0% from Thomas or you could have gotten 3.125% from Thomas but with none of it from Owen. And again, there's no way to know whether you got any of Thomas or Owen's x.

Now think about this -- 3.125% of 46 chromosomes is only about 1 and a half chromosomes. So in five generations, the entire inheritance is a full y chromosome plus maybe another one and a half. In ten generations the entire inheritance would be the y chromosome plus 4/10ths of another chromosome (or perhaps no other chromosomes). In other words, after 10 generations the only inheritance you have from Owen Tudor s probably some stray fragments that survived by crossing over into another chromosome.

Re-reading your message, I think you see that whenever a woman has Tudor ancestry and marries back into the line, you don't get to start over with her as though she is 100% Tudor. Instead, you have to go back through this same sort analysis for her. Figure out how many generations she was from Owen. If she was also five generations, then you get (for that generation only) a doubling factor (minus the chromosome).

So Tamazin (or whoever might bring another 3.125% of Owen's DNA. And if her husband also has 3.125%, then their children will have 3.125%. In other words, you get to skip a generation of cutting the number in half ;)

As you read this, please understand that when I talk about percentages, these are just predictions based on randomness. In fact, a whole chromosome could get passed down even though the odds are against it. Or a chromosomes might be affected by cross over. 3.125% isn't a predetermined number; it's just rough guess about what will happen in a completely a random system.

Of course, random is random. If you toss a coin four times you don't always end up with two heads and two tails. In any one generation, you might beat the odds, but over many generations it will tend to even out. There's no reason, other than probability, that you couldn't have inherited a couple full chromosomes from Owen, in addition to a y. You could even argue that in every single generation since Owen's son, all of your ancestors inherited the "Owen half" with never any contribution from the female line, so your DNA is really 1/4 identical to Owen's. But the odds against that are astronomical, and you'd never be able to prove it.

If your goal is to find reasonable genetic evidence that connects you to the Tudors, you want to focus on arguments that will help persuade people who know the field.

O.Tudor+ XY= Griffeth + Tudor X@ 50% &Tudor Y@100%
Myveney XX
HelenTudor+XX= Griffeth/Tudor X=2 @ 25%+ Myveney at 50%

Gardiner, wm.XY

Beatrice Tudor/Gardiner + Henry TudorTudor=2x+1/2x +1Y = William Henry 1521 Tudor both sides but X is reduced by 1/2 Myveney+ 1/2 Helen Tudor or .75 Tudor X + 100% Tudor Y( can one express it this way and make sense?)

Dale, before we go on I want to make a suggestion.

But first, a personal story. Ever since I was a kid my passion has been medieval history. Every other part of life, even sex, drugs and rock-n-roll, was just fluff until I could I get back to studying. I didn't take math after geometry in high school. I dropped Statistics when I changed my major from Accounting back to History. The only use I ever saw for math was knowing how much money I could spend. And, I didn't care much for science either. High school chemistry and biology, then I was done for good.

That is, until genetic genealogy in the late 1990s. Then, as an adult, I taught myself all math and science stuff. I learned how hopelessly out of date my high school biology was, and how little of the math I knew was actually useful for what I wanted to figure out.

I learned exactly the way you're learning now. I cornered every expert I could find, and I spun elaborate theories, and I came up with new ideas about how my theories could be true and how I could prove them.

The experts were all very, very patient with me. Sometimes they told me I was an idiot, but they didn't give up on me. Now, I like to think that their patience with me paid off, because I'm an Admin for two family DNA projects at Family Tree DNA, Admin for one regional project, and co-Admin for the Scandinavian project. Every day now I spend time helping people figure out how to use DNA to figure out what they want to know.

So, with that in mind, what I would suggest to you is that you get an autosomal test and spend some time working with Family Finder. It's a great learning experience and there are many users here on Geni who are deeply involved in FF research who could help you.

When you work with something like FF you get to see first hand how the whole thing works. You see your own DNA map and the DNA maps of hundreds of likely distant cousins. You can see the segments you share with each one of them, and you see how the computer knows you're related. Then, as you work with other people to figure out who your common ancestors were, you get a feel for the practical applications.

You start to see, Oh, that 8 cM segment on Chromosome 3 and that little 3 cM segment on Chromosome 8 are pieces are all that cousin Grace and I have in common from our 2nd great grandparents. (Shouldn't we have more??) Or, I think that little Ashkenai segment on Chromosome 4 that overlaps just a fraction with cousin Tom's longer Ashkenazi segment is probably my individual slice of the larger segment that belonged to some Ashkenazi ancestor (So, which one of our recent ancestors was Jewish?) Or ...

If you spent some months doing this kind of work for yourself, I think it would answer most of your questions. You would start to see that you have just a few tiny pieces that might have come from your Tudor ancestors, and you would understand the complexities of proving where it came from. It's all a very labor-intensive, patient triangulation.

AH....So!

Masterful summary.....I beleive we are trending in the general direction....LOL! "OH look at that segment on Y15, looks like Uncle Edmund made it back home!" LOLOL....they will lock me up and I will blame you......bahahahahaha!

You might be interested in Cece Moore's genetics blog. I've been following her project to triangulate her cousins and build a chromosome map of her ancestry. Here's a recent example:

http://www.yourgeneticgenealogist.com/2013/07/a-second-cousin-adds-...

Look way down at the bottom, and you'll see her current map.

You might also be interested in hiring Dr. Tyrone Bowes to give an opinion. He's been all over the genetic genealogy news the last few months. He claims to be able to pinpoint an ancestral homeland (1,000 years ago) in the British Isles within a 5-mile radius by triangulating matches and near-matches in a 67-marker y-DNA test.

http://www.englishorigenes.com/

I've been corresponding with him about my Swanström ancestors to see whether his methodology would tell me whether they were in Sweden or in Scotland. He tells me he has an answer to my question, but of course I will need to pay him before I find out what it is ;)

Wow, only a well oiled computer program could crunch that much data on disparite individuals come up with an answer....I suppose to they didn't move around a lot unless under duress....Good for him....Most likely couldn't afford him....I only spend what I can scrape together on Social Security....so not landed gentery here Im afraid.....Very good info....Thanks. DCR

Justin: I was headed toward the Chromosome Map with my rudimentary idea about how much X and Y would be by percentages....and thank God I don't have to invent that!!!! HA....like I could....right? I just want to maker certain of one Idea and I'll leave you alone....I understood you to say that we get our looks from the DNA marching instructions we receive but most are outside of the control of the Y Chromosomes....I get that! So is it the X chromosome that directs inherited defects like the eye socket allignment? Or for that matter Skin Color? I would seem that the most basic control for skin tone has to be on the same X in the same place for men and women and the recessive black gene has to be present or the white gene of the female X could combine with any ole white gene to make a Black or Brown, yellow skin tone....You may recall that Charles the II is known as the Black or Dark Prince because of his deep tone skin, hair and eyes....My view was that there had to be a recessive gene present in the Father and the Mother for that to occur.....because Im pretty sure the Scandanavians do not have Black skin tones any more....say the last 50,000 years without a message for black coming from one parent at least....Obviously two white persons could have recessive black and not know that and cause all kinds of trouble for the the Mother....Is there a hierarchy of inherited conditions that lock in on the gene in question that controls that feature? Two Brown eyed persons can throw a brown tone or Red/brown town because the recessive is in both lines....but never a blue unless the recessive blue is in both lines....? The point I was trying to fully grasp is : Some thingns are set in concrete so to speak while others are completely random....and therefore subject to coincidence....I don't think you said all features are completely random did you? That's just too broad a brush to comprehend....DCR 1948

Justin said, "I have a pet theory that there might be a level of organization that causes some genes to be inherited together preferentially, and causes certain gene clusters to prefer recombination with others that help maintain certain patterns, but as far as I know there isn't a single other sane person in the world who agrees with me."

(Jumping in late because I'm trying to catch up after being offline for several weeks), I just need to say that (a) I've been noticing the same facial patterns for more than thirty years - I've even named certain types that I look for - so I guess that means I agree with you, and (b) I'm sane today. Yesterday was iffy and tomorrow's uncertain, but today's a sanity-day. I think.

And thank you for DNA 101 As It Applies To Genealogy!

" There are no physical characteristics on either the x or y chromosomes, so they won't determine whether someone looks like a particular ancestor. "

Quoting from Justin above.

Thank you Ms Erica, I re-read his Paragraph....I see it there but where do looks come from then? Genes, on X or Y ? aparantly not....I can tell you this much...I have seen descendants of persons I knew in the past and knew instantly they were related because of shared facial features/placement/spacing/ eye colors and maniserisms....I once Mistook my wife's Blood born sister, seperated at birth from her after our divorce in the 3rd year or so but she was in the wrong part of the country and smoking which my wife would never do....I could not understand what she was doing there....and became very paranoid about her presence....Finally her demeanor gaver her away as NOT my wife, but it turns out she was her full blood sister.....If you tell me I cannot discern my wife's face from her sister at 20 ft. then we really are never going to find what is being transmitted and how....My wife's best friend from high school had seen her before and mistaken her for my Wife VJ....and when she heard both my story and how the two had finally met....her statment, " OH my Gosh, every time I went through the check out line she was in, I kept thinking she looks just like VJ...." NOw tell me how random that is unless there is a resivoire of similar genes along an axis on the X chromosome....where the heck do the features come from? If not Y and we can understand that...females don't have it...then by default are not talking about X? What other gene's are there to store and pass alolng such data to the developing fetus? It's in the X Chromosome....It has to be there is no other place to store the information except on X.....IS there?

PS: The woman I grew up with as my step sister ended up marrying my full blooded brother Jay when he came back from Korea....They had not met before my mother remarried Judy's Father......so I know this woman fully 100%. In 2002 while working for Lowes Hardware as a specialist...in walks my Stepsister with a man I know not to be my Brother....and I live in Palm Springs Ca. and They barely if ever had the left the state....After getting over my initial Shock of seeing My Judy wearing her exact same hair color very long and pulled back revealing the same skin color, eye color, finger shape ( I study hands and feet) and in listining to her voice....I can tell you that this woman has to have come from a loose gene in Her Father's past....Not only did the woman look, move, and act like my step sister....I explained myself and asked her if she liked to fish? Before she could answer, her husband said," She out fishes everyone one of we men in the family, and manages to catch the largest fish of the day!: Well don't you know, my step sister is also an avid fisher woman and very successful at it to...." Understanding what you said above, is an intellectual exercise that I can follow, but my experience tells me the DNA story is not fully yet understood and my role in relating them to you is cause a deep search of the current data that allows both conditions that Im trying to express to you but on the framework of DNA science as presently understood....together with my family history, and the COINCIDENTAL double gangers of 8/25 in the #3 generation since DNA from the past was exchanged....you get why Im stumbling here? Something is utterly wrong in the notion we look the way we do by chance, or I would just have well been born with chineese features or black skin in the Randomness Im hearing from you....and please hear me, I do believe you, I just don't think the final understanding is in of family features passed down.....I would gladly submit to any test you would suggest....I think I will be send for the Y 31 test, I hear there is a Y 37 test also....That would be this comming Wednesday all will go into a site you would recommend since I have the Money together now.....fyi

PSS: Last Word on DNA, My mother's maternal grandmother is a CHALFANT from the area north of London....a very ancient family seat at Beaucleaux.....Thus the X mixing into Tudor X and Y has yieldind something unique perhaps? Or Not....I don't have a clue....I just know how to recognize a face as a POLICE TRAINED FORENSCIC reconstruction investigator, I can tell how fast and what mass the two cars had at a crash scene....the multiplier effect in that line of investigation seems to be at work in the DNA....Mass = WT X Speed.....and smaller vehicle going 60 has the same mass as a Cadillac going 20....capishe?

Dale - you are, I believe, mixing up Mendelian genetics with the very new science of DNA for genealogy.

I think it works best to throw out everything you you know about "inheritance" when looking into this DNA stuff. Just put it aside, don't concern yourself with trying to reconcile it with phenotypes, it won't go anywhere because ....

They are two different things.

Dale, this part is pretty simple.

The x is just one chromosome out of 46. The physical characteristics you inherit aren't on the x or y chromosomes. They're on the other 44.

You and I are about the same age. When we took high school biology, it was believed that there was one gene for eye color. You got one copy of that gene from your mother and one copy from your father, and whichever one was darker determined your own eye color. So, if you got a blue from your father and a blue from your mother, you would have blue eyes. If you got a blue from my father and a green from your mother you would have green eyes.

That turned out to be all wrong, or at least misleading.

They now know that there are at least 15 genes involved in determining eye color. (Remember, a gene is a small piece of a chromosome.) Could be more that they don't know about yet. The different genes affect the color, the amount of color, the intensity of the color, the distribution of the color, etc.

I don't know what chromosomes the genes are on, but imagine a couple on Chromosome 5, a couple on Chromosome 8, maybe a few on Chromosome 20. Then remember that you get one copy of each chromosome from your father and one from your mother. So, your eye color is being determined by 2 copies each of 15 genes spread out across a couple of different chromosomes.

Now, remember that some genes are dominant, some are recessive, and some will work together so that neither is dominant. Dominance is contextual. Green is dominant when the other copy of the gene is blue, but green is recessive when the other copy is brown. You probably won't get the exact same dominant / recessive pattern either of your parents had.

See how complex it is? You're inheriting your eye color from your parents, but your exact eye color probably won't match either of them. You get a new combination that might not include the gene that made your mom's eyes that particular shade of blue. On the other hand, you could get exactly the same shade if all the key pieces were dominant over the same genes you inherited from your dad.

Now, multiply that by jawline, cheekbones, hairline, nose, mouth, ears, etc -- all of those things are being determined by more than one gene on more than one chromosome. People inherit their appearance from their ancestors, but the genes are being continually re-sorted.

We all have stories about being able to recognize someone as a relative, and also stories about meeting people who looked like someone without being at all related.

The thing to keep in mind is that our genes are spread through the population. My great grandfather had blue eyes, but he wasn't the first person in history to have blue eyes. With the random re-shuffling, it's possible for approximately the same combination of genes to show up in a complete stranger.

That's why my cousin looks like Pancho Villa, why one of my great grandfathers looks like Edward VII, etc. Edward VII wasn't the only man in history to have the genetic combination that made that nose or those eyes. In his immediate family there are people who carry the many of the genes that could potentially make the same combination. But, even if in the general population, the right combination can come together randomly.

There was an article in People magazine about royal look alikes.

http://www.people.com/people/package/gallery/0,,20395222_20484974_2...

I wasn't impressed by the similarities in most cases. The eyebrows are wrong, or the mouth is wrong, or whatever. But, you can see the family resemblance in many cases.

I was far more impressed with a royal doubles website:

http://www.lookalikes.info/our-lookalikes/royals

Ordinary, unrelated people who just happen to look like members of the royal family. Also, NPR did a piece last week or the week before about a man in New York who looks like Barack Obama.

I think the best way to summarize is that people look like their ancestors and relatives because of DNA, but you can't use someone's physical appearance to prove a relationship.

Jennifer, I also think there is something to the idea of "types" and I'm glad at least one other person in the world agrees with me ;)

But, if this is DNA 101 As It Applies To Genealogy then I'd better rush to correct a very newbie mistake I made above.

I said that my x chromosome exactly matches my mother, my sister, and my nephew. That's been bothering me ever since I said it. It could happen, but the odds against it are astronomical.

The whole point of DNA is that it recombines. Inside each of our bodies, the chromosomes we inherited from our mother are recombining with the chromosomes we inherited from our fathers to create new combinations that we pass along to our children. Pieces from one are crossing over to another, so that typically the copy of a chromosome that I inherit from my mother will be a patchwork of what she inherited from each of her parents.

The same thing happens, obviously, with Chromosome X.

As I was writing, I went over to 23andme to verify what I was saying. It showed me that yes, I match my mother on x, that my sister matches my mother on x, and that my nephew matches my sister on x.

As I said, this a very newbie mistake. Part of it has to do with how 23andme displays the data. They show a simple match, but that's a simplified display.

What I should have done is compared myself to my mother, myself to my sister, and myself to my nephew. I had a sudden flash in the middle of the night, so I got up an re-checked, doing it the right way.

In fact, I only match my sister on about 2/3 of the x. She got a slightly different combination from our mother than I did. We each got pieces from my mother's mother and my mother's father, but we got slightly different pieces. And, I only match my nephew on about 1/3 of the x. He got pieces of his mother's x combined with pieces from my mother but also with pieces from my sister's father.

Some day I will do what blogger Cece Moore is doing with mapping her DNA by family line. Not today, though. Too much work.

http://www.yourgeneticgenealogist.com/2013/07/a-second-cousin-adds-...

There used to be a game that taught what we then-understood of inheritance by using marbles... it was great because it made the complexities easy to grasp (literally, lol). Unfortunately, it's going to take someone a whole lot smarter than I to figure out a new version to fit our new-and-ever-broadening understanding! I wish there were some way to simplify and help folks visualize how DNA works but as it stands, without a solid understanding of statistics - which most people sorely lack - it's murky and stinks of magic.

Thanks for clarifying your x-chromosome statement, Justin! It bothered me when I read it, but my assumption was that I must have misunderstood something along the way. Very glad to know that I am grasping the basics - the very most simple basics! - and your explanation helped a lot. I suspect that our understanding of DNA is going to be as much a lifelong pursuit as is building the Big Tree!

Dale,

I forgot to answer your question about Charles II. I haven't made any study, so I don't know the answer. I've read in passing many time that Charles II inherited his dark coloring from his Medici grandmother.

All of the pigmentation genes (hair, eyes, skin) are very complex. When talking about dominance, the genes for darker coloring are thought to be dominant over the genes for lighter coloring. So, it wouldn't exactly make sense for two light-skinner people to both have a recessive dark. But, there's also cases where both genes are expressed, so someone could have one light, one dark and the result would be half-way in between.

Maybe Charles II inherited dark genes from both parents, but didn't get the light genes that would have lessened the effect.

But, I don't really know. If you read between the lines of all my messages above, you'll see that I only learned the parts of modern genetics that are useful to me as a genealogist ;)

By the time we get to the tenth generation, we have 1024 ancestors (presuming none appear twice in our tree), is that correct?

So if I took a carrot and chopped it in half and gave HALF of it to my son, and his father did the same thing, that would represent the way he would inherit just the DNA from ONE of our chromosomes, right?

My son cuts the half-carrot he received from me in half, as well as the half-carrot he received from his father. He gives half of his carrots to his child, who also receives half from his or her mother. Still right?

So that child (my grandchild) can only possibly have one-quarter of a carrot from me, is that right? And when my great-grandchild arrives, he or she can only have one-eighth of one of my carrots?

Only three generations from me, and my great-grandchild is only holding a very small piece of carrot that originally came from me. And that's only one of 44 carrots my great-grandchild is holding.

But instead of remaining distinct pieces, each carrot contains (hundreds? thousands?) of little genes, which combine at each generation into a big ole carrot soup, from which half are chosen at random to be given to the new generation. So instead of handing distinct, individual pieces of carrot to the new generation, it's more like putting half of my carrot in a Cuisinart with half of the other parent's carrot, chopping merrily, and then pulling out a selection of carrot slaw. Again, still just talking about ONE CHROMOSOME, right?

Multiplied by all the chromosomes on all the genes? This helps me understand why it's impossible for someone to "look just like" a remote ancestor BECAUSE of inheritance, although we might look just like a remote ancestor BY COINCIDENCE. Is that right?

Jennifer,

I learned in high school biology that it was like have million different jigsaw puzzles, with the pieces all the cut the same. You choose one of the pieces with the right shape and put it in, but don't know what the picture looks like until you get the whole thing put together.

Now it's kind of the same but so much more complicated. I agree 100% that we genealogists are going to spend a lifetime trying to catch up and keep up with all the new discoveries.

I first had my mt-DNA tested in 1998 and my y-DNA tested in 2000. Even back in those early days I knew this was going to be a game-changer, but I had no idea how much I was going to have to learn.

I also wasn't fully prepared to live in a world where the information changes so quickly. Back in 2000 they were saying that my y-DNA group was from Neolithic farmers moving from the Middle East in Europe. Then it changed, and it was Barbarian invasions at the Fall of the Roman Empire. Then it was Jewish merchants wandering into Europe in the Middle Ages. Then it was Etruscans coming from Turkey to Italy (which was my own contribution to the confusion). Now it's back to Neolithic Farmers.

Any of us who do this kind of work have to be able to land on our feet when a new discovery or a new study changes everything ;)

(A friend told me a long time ago that when we're young we think we know everything, but as we age we learn that we really know nothing. I think it's a sign of wisdom to accept that we'll never really understand much of anything, and to enjoy that!)