Every once in a while, I get an email from 23andme to notify me that I have a new DNA relative. When a new person gets their DNA sampled, and if they have given permission to do so, they send out a message to all the people who have some degree of genetic relationship. There’s a limit, obviously — we’re all related to everyone, so they don’t want to have to send out a notice to all of their subscribers every time someone signed up. It looks like the limit is somewhere around 4th cousins, which is already pretty tenuous. I have over 1500 DNA relatives flagged on the site, most around the 4th degree cousin level of relationship, which means that we share about 0.34% of the DNA inherited from our last common ancestor. I know hardly any of them.
When I look at the list, yeah, I definitely know the top 2 names — they’re my kids. 50% of our DNA shared. I don’t have to go at all far down the list before descending into total mystery. I recognize a couple of cousins, some familiar family names, and then…who are these people? Once you’ve dropped below 4% shared DNA, you’re too distantly related for me to have known you, with some exceptions, not that I would mind knowing you. I’m sure you’re all lovely people.
What I see from these kinds of data, though, is that genes are not at all a good measure of relatedness. Every child of each generation throws away half of one parents’ DNA, so generation after generation “your” genes are rapidly and progressively diluted, unavoidably. If you’re hoping for some kind of genetic immortality, it’s not going to happen, because the mechanics of meiosis are going to steadily break up the particular combination of genes that make up the genetic “you”. You can draw up all the pedigrees you want to illustrate your family connections, but they aren’t particularly meaningful.
As you can see, a fourth cousin would share a great-great-great grandparent with me, but that connection is rather abstract. I personally knew two of my great-grandparents, but anyone before that is, at best, an old black-and-white photo in a dusty family album, or perhaps a line in a census record. 23andme tells me that we have less than a percent of shared DNA passed down from that great-great-great grandparent. Lineage really doesn’t matter all that much, because we’re all just a great sloppy gemisch, a random subset of a population, and it’s the population as a whole that matters in the long run. The unique combination of genes that make up me are going to be broken up and dispersed over time, and some will be lost.
I can’t even stress enough how trivial those genetic inheritances are: I am not the sum of my individual genes, but the product of all of my genes interacting with each other and the environment in complex ways. My kids may each have 50% of my genes, but they are not 50% “me” — each one is unique and distinct, and I can have no claim on them. Part of the pleasures of parenting is creating someone new and watching them become independent and express themselves in ways you wouldn’t have thought of — not as a reflection of yourself, but as someone completely novel in all ways. They may share 50% of my genes, but they’re marshalling them in different ways in different contexts in cooperation with my wife’s genes.
I have no patience with possessive parents who want to mold their children to their preferences. I also don’t have much sympathy for “royal bloodlines” or other such nonsense. The king of England and I might both be related to William the Conqueror, but that drop of blood has been attenuated and reduced to meaninglessness by a thousand years of gene juggling and recombination and drift and mutation and loss. We shouldn’t care any more.
There is something meaningful there, though. I started this post by mentioning my email from 23andme — they had a new member who, they said, was my second cousin. I recognized the last name as belonging to one branch of my family, so I contacted my brother and sisters and asked if they knew who they were, because I sure didn’t. Yes, they did. It wasn’t my 2nd cousin, they were my first cousin twice removed; they were the grandchild of my first cousin. We shared 2.65% of our DNA with my grandparent, their great-great-grandparent, which, as I’ve said is a bit trivial and not at all grounds for showing up unannounced at their house for Sunday dinner. But we do have a connection.
I knew their grandfather well — he was my cousin, we regularly met throughout our childhood and youth to engage in shenanigans at their ranch in Eastern Washington. We hiked, we went fishing, I called him a stupid redneck, he called me a liberal pussy, and he beat me up now and then. It was a sometimes prickly relationship. He got wilder as he got older, while I became more staid, and we drifted apart, which meant fewer bruises for me but fewer wild adventures in the back country. You know, he once killed and ate raw a red-winged blackbird in front of me to prove he was tougher than I was? Kinda grossed me out.
Their great-grandmother, my cousin’s mother, was a rock who earned our respect. She was a tough old bird who raised a sometimes fractious family with love, despite often struggling economically. She was my father’s older sister, and I think she helped hold that family together, too. We visited her a few weeks before her death from liver cancer. She knew it was coming. She was awesomely brave about it all, retiring to a little house on the Palouse, where she could appreciate the country in her last days.
I knew their great-great-grandmother, my grandmother, even better. I spent many happy days in my childhood at her house, which was a crumbling shack next to the railroad tracks, with one wall slowly peeling away from the rest of the house and floors that sagged in odd ways. She had been a widow since about 1939, and raised a family of six kids single-handedly, working as a fruit-picker in season and in a cannery in the off-season. She was always kind and generous with her grandchildren, which was good since she had a great milling mob of them running wild over the house all the time. Sometimes my cousin would visit to twist my arm and make me say ‘uncle’ while I was there.
Those are the ties that bind, the connections that really matter. Native Americans have the right idea — you aren’t an Indian if you have a pedigree that shows some distant relative gave you a dollop of tribal DNA (Elizabeth Warren was taught that lesson a few years ago), what matters is the personal associations, the actual sharing of the life of an Indian. As a biologist, you’d think I’d place more weight on the numbers and percentages and genetics, but no, I’m not at all impressed with a 2.65% genetic share in my twice-removed first cousin’s DNA…but hey, I knew their grandfather, and that matters far more to me. I’d probably enjoy meeting them and having a conversation about family.
Unless they decided to beat me up to prove how tough they were. I would hope that doesn’t run in the family.
I have a first double cousin, (my dad’s brother married my mom’s sister) whom I would be happy to never see again before I die. Even close familial relationships are nothing if the person themselves is trash.
Who would kill a red-winged blackbird?? They’re beautiful. They’re like scarlet tanager’s in reverse. Stupid redneck.
Every person on earth is a cousin to everyone else.
The most distantly related humans on the planet would be my 50th cousins.
Similar to Artor, my father’s brother married one of my mother’s sisters. They had 3 kids. She died in a plane crash. My uncle remarried, to a widow who had a kid from her first husband, and then they had another kid. That last one being the only cousin younger than me, and that only by about 3 months.
My family history was always a mystery. I was told my dad was an orphan and that was that. Turns out none of that was true. In hospice, in his final days, I asked Dad if he knew where his father was born: Sweet Springs, Missouri. That evening armed with a name and a town I signed on to Ancestry.Com for the first time and within an hour had not only found my “roots” but traced them back several generations. Turns out Dublin Bill who immigrated to Kentucky in 1791 and Doc Bill share the same birthday. My dad was not an orphan, although his mother died when he was three and Dad was in college when his father died. My dad had a first wife – man, that was a deeply buried secret – no letters, no pictures, no trace. However, further research has revealed their marriage announcement in 1943, days before Dad shipped out to the South Pacific Theater, and their divorce decree, which paints a real Winds of War story.
Through 23andMe I discovered a cousin descended from the daughter of my grandfather’s first wife (he had three) and we have met. Once believing that we were all alone on our little twig of humanity I have since discovered about five living relatives descended from the many siblings, as each generation had about 10 kids. It’s been a fascinating and interesting journey with many gaps, but every time I discover a new relative or new link it’s a real “ah ha!” moment.
@5 Reading about your discovery of unknown relatives I started wondering if with some DNA service I might find out if I have any unknown siblings. Considering what a dishonest, irresponsible womanizer my father was, I’ve allways thought the chances for any half.siblings are high…
On the other hand, I’m not sure I care all that much ;-)
I’ve been contacted twice by people who found me as a relative on 23andme, and who had been adopted and were trying to find their genetic parents. I was unable to help them out.
I was adopted when I was just three months old. I can’t remember a time when I didn’t know that, so my parents must have told me as soon as I could understand the concept.
I have no clue what it could be like for one’s adoption to come as a surprise later in life, but I’ve never thought that my parents were any but the ones who took care of me when I needed them. I guess that’s anecdotal evidence that keeping adoption a secret is not necessarily a good thing.
I don’t know. I’ve thought about sending them my DNA. But would really hate to get some great grandkid busted cause they found them because my DNA was in the system.
Plus. I’m kinda lucky in the genealogy game. There was a salesman back in the 60’s who took it upon himself to trace the history of my surname. As he traveled the country he would grab a phonebook* in every town he passed thru/stayed in and write down the name, address and phone number of everybody with my surname. When he got home he wrote them all a letter stating what he was doing and asking for any info they had on their family history. Guess he never passed thru Gallup New Mexico. But my Uncle in Albuquerque received it. And ignored it. Once he had all the info he wrote everybody once again. Even if they hadn’t ever replied. And asked if they wanted a copy of the book. My uncle received that one too and my dad saw it. So we got a copy of the book. Since my uncle never replied we weren’t in the book. Later on he put out a supplement.
Kinda cool to read about your ancestral history all the way back to the one guy who came over from Germany in the 17th century and then had 4 sons.
*phonebook, for you youngsters, way back in the past the government required telephone companies to provide a list of assassination coordinates, free of charge, to every household that had a phone.
Some of my brothers and I are close to one of our maternal third cousins, neither side of the family had many closer relatives going up the tree, but my mother and my second cousin once removed were very close as children, the two families often holidayed together. When it came to our generation we saw our third cousin (and her sister) quite a lot as children, three of us really hit it off with third cousin S, but for no particular reason not so much with cousin R, I think probably we just never saw as much of cousin R in our twenties due to where we all lived. And now the next generation are mostly good friends as well despite not living anywhere near each other. But on my fathers side one of the other siblings is close to our cousins while none of the rest of us are. That’s a combination of their ages, where they lived, and in one case their politics – that one worked in apartheid South Africa, a time when as far as the rest of us were concerned doing so supported an abhorrent regime, which was simply unacceptable.
#1 I have 2 brothers I hope to never see again. Yup, I am willing to cut racist, homophobic MAGATs out of my life. Even if they are my brothers.
#7 I was contacted by a woman of whom I was the closest genetic match on Ancestry. Both her parents were adopted. We determine her mother is my first cousin. It seems my oldest uncle had a child before he was married. According to his other daughter there is one more cousin out there. My aunt knew all about this, as he paid child support, but no one else did.
It feels like you’re burying the lede here.
23andme is attempting a legal maneuver to pre-empt a class action lawsuit, which means they fucked up big time and more damage has yet to be revealed. If they’re sending you an e-mail about that, it’s in your best interests to respond in clear terms that you do opt out of this binding arbitration nonsense. They should be to criminal court for giving away details about your genome to others, but at the very least you can hope for civil liability and a class-action payout.
The thing about those royal bloodlines is inbreeding. The current king of England is much more closely related to William the Conqueror than you are, because he’s the product of 10 centuries of cousins marrying each other. And it shows.
My kids signed up for that crap, I never did, so thankfully, I avoid getting that spam.
Entertainingly, the kids were informed that there is no Sicilian DNA in them, but oddly, every ethnicity that was ever involved with Sicilian occupation. Great research, DNA company!
But then, I consider human variability and a couple of legal cases of note, where mothers were accused in court of not being the mother of their own children, doctor’s testimony and hospital records be damned.
Subsequently, in one case on appeal, with the courts learning that both mothers had two distinct sets of DNA. Vanishing twin apparently not being as rare as it initially was thought to be.
And confirmed in a man’s DNA test results that one news channel years ago tried to scandalize, where he was apparently unrelated to himself, having provided two different samples under two different names and yes, he also is a chimera.
Which makes me wonder, if a court ordered two DNA tests from me and it was found that I’m unrelated to me, would I have to divorce myself?
And would I need to sue to gain visitation rights to myself, just so that I could talk to myself?
DNA exclusively is important in very few things. Parentage (and I mentioned some difficulties with that), genetic diseases that may be symptomatic or for reproductive guidance and criminal cases, with some significant input for transplants as well. Beyond that, not a hell of a lot of worth.
Although, somewhat tempting, as my beard and one patch of my scalp hair both have/had blonde, red and brown hair mixed together, suggesting possible chimerism as well. It’d also explain why I spend so much time beside myself.
I’ll just get my coat…
Wait, is Nick Fuentes’s brother a commenter on Pharyngula?
Dunc @ 14
So William had big ears, too?
Fortunately for the aristocrats, they will be able to afford germ-line gene editing when it becomes an option (never mind rules and laws, it is not like it applies to them especially as a grey market springs up in labs at countries with flexible rules for GM)
I predict there will soon be a hidden market of GM for billionaires who want their offspring to have every genetic advantage possible, and the aristocrats will obviously exploit the opportunity.
A concept a lot of people just don’t seem to be able to get a handle on – it’s a gene POOL, not strictly linear.
My own genes have been far more efficiently spread by my fecund sister than my own kids who haven’t spawned (yet).
The interesting thing is where physical characteristics have shown up after multiple generations and in unexpected places. My daughter takes after my maternal grandmother in terms of height (5 foot nothing and sick of looking up at the rest of the family) whereas I seem to have developed the body plan of my paternal grandfather (unfortunately).
#6 I’ve got 2 half sisters because my father was irresponsible . He was also the first man to say that child rearing is women’s work . Which is why he dumped the youngest on his sister ( my aunt) when my sister was a baby . But he wasn’t as bad as my uncle who had several children by different women including 4 marriages. . I know all these people and consider them kin. The culture they both come from consider women to be either a wife ( household drudge who gets the house and the abuse ) or a girlfriend ( gets abandoned when pregnant but might get some clothes and jewelry while dating) .
The other half of the family great grandparents who had around 15 kids. I know a lot of them too . I’ve got cousins by the dozens
“When I look at the list, yeah, I definitely know the top 2 names — they’re my kids”
2 names? I thought you had 3 kids?
Do you need to start giving the milkman suspicious looks? ;-)
Eleanor and Franklin D Roosevelt were 5th cousins. Which isn’t odd. Lots of people marry their 5th cousins without realizing. The odd thing is that they married when they knew each other as most people know their 1st or 2nd cousins. As a biologist, I know that marrying your cousin (even your 1st cousin) doesn’t carry a significantly increased risk of birth defects, it’s marrying a known family member that would creep me out. At least with my family, anyway (YMMV). Old money is weird.
#6 Mordred
Ah, a funny thing happened on the way to the testing lab …
A few years ago a cousin appeared with a high percentage match, 4%, equivalent to my discovered cousin of known pedigree. I sent her a message and the game was afoot! Her daughter replied to me saying that her mother died in 2015 but submitted a sample to 23andMe in hopes of discovering her family as she was adopted as an infant. Well, she is definitely in the Doc Bill clan and we have a potential culprit that her father could have been my great half-uncle. This guy was divorced by his wife between 1920-1930 which puts him in the middle of the range of years to be cousin’s father. Divorce was rare in the 20’s so it must have been a big deal; something significant.
I suspect that cousin was a love child of my randy half-great uncle, and I have been searching records since hoping to get a hospital record or, better yet, divorce papers crying “INFIDELITY!” Nothing yet. That said, every year tons of old records get online and also you often “meet” people searching your family tree. Another hope is that a random researcher out there is also looking for “cousin” or discovers a common link. Fun stuff!
In my searching I came across the daughter of the guy randy half uncle’s divorced wife married; they had no children of their own, but my “find” had only dim childhood memories of Aunt Jo Jo, as she was known.
I’ll also add that my 23 & me test came back Eastern European Jew, which I already knew. I was expecting to find out how much other DNA I’m carrying around from intermarriage and the occasional raping and pillaging band of Cossacks, but it just said Eastern European Jew and nothing else. There was a short explanation that we’re more closely related to Arabs than Eastern Europeans, but I also already knew that. It was far less educational than I expected.
Excellent post, PZ. I’d also point out that royal bloodlines are almost completely genetically arbitrary. Anyone directly decended from William the Conqueror is, genetically speaking, as close as any of the current royal family (with a little difference in terms of inbreeding, as Dunc points out above, although cousin marriages were not uncommon outside the aristocracy either, e.g. Darwin, Einstein, Grieg, H.G. Wells…).
The supposedly protocol-bound heritance rules are bound to the firstborn son, who is no genetically closer to the parents than any other sibling, made even more capricious by child mortality, coups, generations without a son, and social stumbles like the abdication of Edward VIII.
9) @JimB
We may be related! I don’t think so, but there was a fellow on my family tree that did a similar thing with my surname (though iirc his collection methods differed, and I don’t recall the traveling salesman thing – I have a vague memory that he might’ve been military), and published a book and gave out copies and all. I think our surname in the US began with two brothers from England, though I have a good deal of German roots as well.
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What I found most interesting from leafing through the tome was that about 3/4 of Americans with my surname descended from one of the brothers and only 1/4 from the other (I’m on that branch). That was a pattern that seemed to hold true over the generations. In an age when not getting married and having kids was extremely suspect, a lot of people on Brother B’s side, esp the women, never married at all. I prefer to think this was a trait denoting staunch independence rather than that no one would have them. Or maybe his side of the tree was just more fabulous! ;D
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There is someone with my surname who’s been in the news lately, so I looked them up and thought that they did look related. Something about the eyes reminds me of my father’s. I don’t have access to the book now to see how closely related they are though. Not very, I hope.
On my bio-dad’s side, there were 40 of us first cousins. But that’s only the people I know about. To a near certainty, I have a stray half-sibling somewhere out there, and one of my cousins was likely a half-sibling as well, given dad’s long time affair with his brother’s wife. It would not surprise me that there are a few more stray cousins out there as well.
23 and me? Hell no!
Ignorance is bliss. There’s reasons I haven’t spoken with the cousins for decades. My bio-dad’s reproductive history is of little interest to me.
Well, excepting my existence.
Meiosis, even your siblings aren’t all that closely genetically related to you.
People have mentioned finding older genealogical data… Both of my mother’s parents came to the US from Denmark, independently. They met and married in the US. My father’s paternal grandfather came to the US after leaving Germany to avoid being drafted into the Franco-Prussian War of 1870.
My father’s mother is where is there are records going back a ways… Her sister was a member of the DAR. The requirement for that organization is that you have trace back to an ancestor that fought in the US revolutionary war. I am in possession of a draft of her application showing the line back to the father of the guy who was in the revolution (he being listed as hero–he commanded a very small war ship–and martyr–he spent some time as a PoW). So that gets me back to a colonial immigrant born in 1720.
Addendum… Here’s a link to a picture of the guy from the revolutionary war: https://www.charlestonmuseum.org/research/collection/captain-william-hall/C6817C6A-A013-4A49-8CC3-475248257440
My mom got into one of those DNA testing companies a few years back and “discovered” that she may (or may not, there was no actual definite evidence, just a bunch of maybes) that she’s fifth or sixth cousins with actor Sam Neil. Personally, I’m dubious and not sure why I should care even if it is true.
“The king of England, the last of which died in 1702, and I might both be related to William the Conqueror”… FTFY
The language is a little unclear, but I don’t fully understand the statement:
“We shared 2.65% of our DNA with my grandparent, their great-great-grandparent, which, as I’ve said is a bit trivial”
Is this the figure 23andMe has provided?
If so it is interesting to compare it to what could have been mathematically predicted.
I really like the facts that with some relatives you can say exactly how much genetics you share – you get 50% of your genes from your mum and dad – I’d love to understand how this is “randomly selected” with all the statements about deterministic processes not being random.
While you share between 0 and 100% of the genetics with your sibling – a twin and an “anti-twin” with maths giving an expected value of 50% for the average sibling.
The percentage you and your 1st cousin twice removed are mathematically expected to share is 3.125%.
So if 23andMe is telling you it is 2.56%, then the genetic lottery is a little closer to the anti-twin than twin! Fascinating.
@microraptor #29:
Because he’s the Antichrist!
chinahand @ 31, I’, aware of no mathematical means to determine the genetic product, post fertilization and recombination/silencing/etc. The processes involved remain under active research and only partially understood. Perhaps PZ could fill in some of the gaps.
So, straight math won’t give a reliable “percentage” relationship of parents to child DNA sequencing.
Way too many moving parts, it’ll never work. ;)
Be careful people, a recent article reported 23&me (whose data security appears to be a farce) had the personal data of millions of customers stolen.
#16 No relation. Though I do have a nephew that shares his name. Nick’s last name seems to come from a Mexican grandfather. I guess he disavoe=wed that ancestry and says he is of Italian heritage. My family is Puerto Rican. My father was born in Arecibo, PR in 1936. His family moved to NYC in 1946.
I’m also adopted. My birth parents are a complete mystery to me. I guess I could use a site like 23andme or something but I’ve always heard they’re kind of sketchy. Another one of those “helpful” sites where you’re the product whether you know it or not.
@31–
23andme’s webpage on the subject goes into more detail, explaining variations in the heritance percentages and the increasing chance of not detecting a familial link with more distant relatives.
The ancestral branch I am most informed about is that of my maternal grandmother. And even there the trail runs dry with her paternal grandfather. He defected from the Hungarian army during the revolution of 1848 and settled in a small village in what is now Romania (yes, my family tree from all sides has a strong Transylvanian presence). So he had 2 reasons to stay on the down-low: both as a defector from the military and as a Jew, as at the time Jews in Hungary were only allowed to live where there was an established Jewish community. I guess he lost touch with his family of origin. But on 23&me I found a ‘DNA relative’ with the same surname and claimed roots in Hungary with some nice looking genetic similarity. For these distant relatives what matters is not just the percent of shared DNA but also if there are any shared consecutive fragments. Anyway, I exchanged some emails with this person’s wife (she was the genealogy person in the family), and this guy could plausibly be the descendant of a sibling of my great-great grandfather (if so he would be my third cousin once removed), but we couldn’t nail it down definitely due to lack of information. Kind of cool, but that’s about it.
@35. Bruce Fuentes :
Any connection to the Arecibo radio telescope at all?
Also would I be right in thinking the word ‘Fuentes’ has something to do with “fire” in etymology – thinking Tierra del Fuego meaning “land of fire” here?
StevoR, (1) The telescope began construction in 1960, 14 years after the family moved, and (2) “fuentes” means “fountains”.
@ ^ John Morales : Okay, thanks.
Thought the Fue but might’ve menat “fire” but espanol no hablas.
^ Bit not “but”” natch. Thought the ‘Fue” part of the word might;ve meant fire that was. With suffixes then being “Fue-ntes / go / etc? I really cannot fucking type these days, apologies.
‘costa rica’ means ‘rich coast’, ‘tierra del fuego’ means ‘land of the fire’, not ‘land of fire’ which would be ‘tierra de fuego’. And, no worries, I can read what you write.
The difference an ‘l’ makes huh? Cheers again.
De vs del that is – did not know that.
I did three years of french in high school and Japanese / Nihongo at uni – so much forgotten there – but yeah, so much forgotten & of course, Francais and Espanol are different despite being quite similar Romance languages too.. Then there’s Aussie slang vs Engilsh, dialects and vernaculur & useage vs strictly grammatical..
You’ve shared so much about your family over the years, I feel like I know them too.
@ #34 – I knew there was a reason I keep ignoring all those 23&me ads Ancestry keeps loading my email with…I pay them $300 a yr for access to records…not to sell my data to the highest bidder…PLUS, given what I know of the archaeology of Europe and anthropology in general, I can’t imagine how they could determine what your genetic ancestry was beyond a hundred years or so lol. There were so many invasions, migrations, etc. over the continent in the last 2000 years that any population would be mixed beyond analysis…