Carl Zimmer, in the NYTimes, discusses the surprising commonness of genetic chimeras:
… [S]cientists are discovering that — to a surprising degree — we contain genetic multitudes. Not long ago, researchers had thought it was rare for the cells in a single healthy person to differ genetically in a significant way. But scientists are finding that it’s quite common for an individual to have multiple genomes. Some people, for example, have groups of cells with mutations that are not found in the rest of the body. Some have genomes that came from other people.
“There have been whispers in the matrix about this for years, even decades, but only in a very hypothetical sense,” said Alexander Urban, a geneticist at Stanford University. Even three years ago, suggesting that there was widespread genetic variation in a single body would have been met with skepticism, he said. “You would have just run against the wall.”
But a series of recent papers by Dr. Urban and others has demonstrated that those whispers were not just hypothetical. The variation in the genomes found in a single person is too large to be ignored. “We now know it’s there,” Dr. Urban said. “Now we’re mapping this new continent.” …
Chimerism, as such conditions came to be known, seemed for many years to be a rarity. But “it can be commoner than we realized,” said Dr. Linda Randolph, a pediatrician at Children’s Hospital in Los Angeles who is an author of a review of chimerism published in The American Journal of Medical Genetics in July.
Twins can end up with a mixed supply of blood when they get nutrients in the womb through the same set of blood vessels. In other cases, two fertilized eggs may fuse together. These so-called embryonic chimeras may go through life blissfully unaware of their origins.
One woman discovered she was a chimera as late as age 52. In need of a kidney transplant, she was tested so that she might find a match. The results indicated that she was not the mother of two of her three biological children. It turned out that she had originated from two genomes. One genome gave rise to her blood and some of her eggs; other eggs carried a separate genome.
Women can also gain genomes from their children. After a baby is born, it may leave some fetal cells behind in its mother’s body, where they can travel to different organs and be absorbed into those tissues. “It’s pretty likely that any woman who has been pregnant is a chimera,” Dr. Randolph said.
As scientists begin to search for chimeras systematically — rather than waiting for them to turn up in puzzling medical tests — they’re finding them in a remarkably high fraction of people. In 2012, Canadian scientists performed autopsies on the brains of 59 women. They found neurons with Y chromosomes in 63 percent of them. The neurons likely developed from cells originating in their sons…
Much more at the link. I do believe that “the universe is not only stranger than we know, it is stranger than we can know”, but there’s such joy in prying new info-bits loose from the tangles of the Great Web of Being!
Hmmm… so much for convictions based on DNA evidence.
This destroys Maury Povich’s whole business model.
@Joseph Nobles: From your lips to God’s ears…
@Joseph Nobles: I was thinking a little less crass commercialism, but yes. I was feeling bad for all the fathers who are going to be told they’re not actually fathers. And all the parents who lose child support because their other parents aren’t 100% genetically the parents.
Except where mothers pick up the DNA of their children, it looks like the chimeric DNA is still unique to the individual. So that would mean false negatives, rather than false positives.
We are not amused.
Villago Delenda Est
Other implications are staggering. The notion that we can just file people in set genome drawers becomes ridiculous. A genetic anomaly that might cause cancer in one person, might be an ironclad defense in another.
This just opens up whole new degrees of uncertainty in how our bodies work at the cellular level.
Damn herds of zebras upsetting the medical applecart.
@Villago Delenda Est: I love these posts where I have NO clue.
And they said we were schizophrenic.
We are! No we aren’t! Are too! Are not!
What was this saying about insanity being genetic, you get it from your kids?
@Villago Delenda Est:
I’ll be honest and admit I did n’t read the whole thing but if the genetic differences are localized I would think the defense against, say cancer to use your example, would be too. Maybe that would only protect the liver from cancer or the brain from tumor. But it does bring up a lot of interesting avenues of resarch
@Linda Featheringill: I admit it, mine drove me crazy.
I need coffee!
@raven: This is an example of a news story, the Morning Joe crew will ignore.
Now we know why mothers of teenagers suddenly stop cleaning up after their children!
The NYTimes science page linked to this article at the Smithsonian. This is an example that my twin and I can understand. link
Lord, defense attorneys are gonna be salivating over this one.
So incredibly cool. I’d heard of the kidney transplant woman before, but I hadn’t known how widespread chimerism is. SCIENCE IS AWESOME!
I had read about chimeras before, but only in terms of their rareness; ha ha ha, we are more complex!
And many of us may have absorbed another in utero… creates some great philosophical concepts, doesn’t it?
@WereBear: And many of us may have absorbed another in utero… creates some great philosophical concepts, doesn’t it?
Since I live in GA, science classes will prevent the study chimeras because of this reason.
just accept that you were created that way and all will be well.
@JPL: I was so pissed of at his punk ass this morning I had to just take a two-mile walk.
@raven: Let me guess, it was Obama’s fault. Not sure what it is though.
@raven: Just called my friend that lives like two blocks from the Navy Yard. I was like, what is going on. He told me “dude trying to get my kids ready for school, caught me at a terrible time. Will call you back.” That to me was music to my ears. You get on getting on …..
@JPL: He went off because Obama went ahead with the presser and attacked republicans. “If Bush had done it the pundits on THIS network would have gone nuts.”
Obama should have just started reading My Pet Goat like a real man.
I understand that in GA, the earth going around the sun is a controversial issue. (I spent my teens years in Florida. Back when, I actually GOT a science education.)
Ya know, I don’t mind people fleeing back into the middle ages; I just wish they would do it right, like the Amish. The Xantians want a Dark Ages worldview, AND microwaves, cell phones, and antibiotics.
You can’t have one without the other.
So, watching a later segment and the question they are asking is what was the point of the news conference being held when the shit was still coming down at the Navy Yard? I can’t answer.
Does he think he’s not a pundit on that network?
@kc: I’m pretty sure he has a designated segment that would be considered “editorial” right at the start of the show. He followed his anti-Obama rant by saying “Now let’s piss off the other side” and went after guns.
@raven:My dad is bad ass mother fucker .I don’t know who you get in there but well to be honest I could care less. Put a bullet in his chest.You don’t go there.
Would you be discussing Morning Joe?
Haven’t turned it on since June or July. Tuned in today to see what they’d be saying about yesterday’s mass shooting. However:
“Next up: Simpson and Bowles.” And there’s Simpson, smiling and chafing to get in front of a camera.
*click* goes the remote
@Tommy: I’m missing something?
By definition, the father has always been whoever the mother said he was, so I don’t think this will change that much :-)
Looks like Joe Haldeman said it best: we are just a bag of cells with a common purpose.
Sister Rail Gun of Warm Humanitarianism
@raven: Wasn’t that press conference already scheduled?
@Schlemizel: IT’S NOT A TOOMAH.
@Sister Rail Gun of Warm Humanitarianism: Yes. And I guess it was more a statement than a presser. I wasn’t that crazy about it, he started with the usual bit abut the shooting and then went to the economy. The people behind him were half-way smiling and it was just very bad optics.
Wow. Thanks for posting this.
@cvstoner: I think you’re trying to be funny, so I’m trying to be charitable, but as with most legal statements that come out of this blog, that’s an oversimplification.
Not that I’m complaining: simplification is a great boon to understanding. But the real world doesn’t behave according to our single-variable models. The glibertarians can’t understand this and that’s their major malfunction. A sign of a mature intellect is the willingness to ask what’s missing from the model.
This ties in pretty well with the finding a few years back that humans and dogs have also shared DNA. Our genetic makeup isn’t as rigid as we have originally thought.
I thought it was bad politically too.
Maybe he’s pissed and frustrated. I know I am. The fact is no one wants to do anything about this. We’re going to have mass shootings every couple of months and we’ll run the same “could this have been prevented?” analysis and nothing will happen. The talk followed by no action, over and over and over, starts to feel like it’s become a replacement for doing something.
a hip hop artist from Idaho (fka Bella Q)
@WereBear: There was an article in the New Yorker years ago that discussed twins becoming singletons in utero. Damned if I can find it, but that was my first thought about chimerism. Among the points in the article is how commonly pregnancies begin as multiple and finish as singletons. I believe it also described how the phenomenon was observable though serial ultrasounds, and that docs had learned not to remark on twins at the early ones.
The article was about twins in general and that was a side note, but turns out that the author may have had a prenatal twin as his mother described a 1st trimester event that could well have been an early miscarriage. I’ve been looking for that article online for years (hint) as the hard copy is long gone from my collection.
The Other Bob
So people who have had their genetic family tree mapped might have got it all wrong?
@Big R: I think that what will happen is that this will generate a whole new set of genetic tests.
That’s the craziest shit I’ve read in a long time.
@a hip hop artist from Idaho (fka Bella Q): Yup. I had a home birth and the midwives examined the placenta and told me that they thought that I had originally been carrying twins and that the child that was born, my daughter, had probably “absorbed” the other. And, of course, Aunt Toola in My Big Fat Greek Wedding recounts that they discovered her twin, in her own neck, after a bib-opsy.
@The Other Bob: No, not all wrong–they probably failed to include all of it.
The purpose it has is to plant the idea of gun control, to make it acceptable to all. Right now, Cleek’s Law is driving the opposition to gun control. Like a lot of issues, enough conservatives support the policy that it should pass, but because it’s a liberal (and thus Obama’s) position they will scream and dig in their heels to make sure it doesn’t. When the existential freakout ends, or demographics tilt the numbers so they don’t have the power to block everything, all of a sudden everyone will want gun control and everyone will know that Republicans are the neanderthals who opposed obviously decent legislation. Obama’s speeches now solidify this result. It’s a little like how marriage equality went from nonexistent to blooming all over the place in a couple of years.
@aimai: Basis for The Dark Half, by Stephen King.
It makes a kind of Darwinian sense… that race to fertilization might happen close enough in time that the signal to back off egg release wouldn’t happen before a few more, did.
Why should the woman gamble that THIS match turns out to be the strongest? Why not have a few, Thunderdome it, and then take the best of both worlds, so to speak?
We are vast! We do contain multitudes!
That was awesome, and I hope to see it replicated on all sorts of issues. The Republicans look monolithic because they have done everything short of arresting Democratic voters at the polls.
But when you have so many teetering objects shored up with last ditch techniques; a chaos cascade is sure to follow.
At last, I have proof that I am part Unicorn. I knew it!
I was watching old episodes of The West Wing a couple weeks ago and came up on the moment where the gay soldier’s father gives an angry speech on how the president has taken “such a weak ass position on gay rights,” and ending with “I’m not ashamed by son’s gay. My government is.”
There’s something absolutely cathartic about watching that speech now, already years after Obama came out for gay marriage and when state legalizations have been blossoming like flowers. And I’m a millennial. The West Wing was my generation – it’s what every kid in the School of Public Affairs at my undergrad was watching a few years back. Already it’s obsolete (or at least that part of it is). It’s nice to see the arc of human history bend from time to time.
Sure is. And that is why I am somewhat confident that the tower of lies the conservatives have built will topple soon and fast. From a market force they have not even considered, called:
This is dark, but this is what I was thinking yesterday. What if the Connecticut slaughter, which had the huge social and cultural imperative of “adults protect 1st graders” attached to it, where we still did nothing, was not “crossing a line” (as I thought) but instead pushed out the line of what we’ll accept?
Does it get worse than 20 first graders slaughtered at school? Once we did nothing in response to that, what will make us act? Do you see what I’m saying? Are all the shootings that will happen after NOT as horrifying? Did we set a new low of acceptable inaction after CT?
I know it’s dark and defeatist, all that, but is it also possible that happened?
Also strange: there aren’t just lots of bacteria in our guts which are crucial to our daily survival. (Not to mention that many of our cellular organelles such as mitochondria are merged bacteria.)
They apparently not only perform crucial functions, but communicate & cooperate with other human organs systems.
We — and all animals, and perhaps most land plants — are colonial organisms, who exist as both mergers of ancient prokaryotic life into our eukaryotic makeup and as mobile colonies of bacteria and other microbes.
It appears that our genetic and cellular structure is predicated upon cooperation & symbiosis, and not selfish competition, and problems arise largely from the failure of regulation within our bodies.
@Kay: That is what happened, for conservatives.
But not all of us are. The official media and Congress are simply the most visible of our centers of power that have been co-opted by fools and madmen.
But we are, in response, growing new ones that we can’t even glimpse yet. What am I basing this conviction on? Merely the fact that this is how history has always worked before!
@a hip hop artist from Idaho (fka Bella Q):
My dad found this out when they saw what they thought was a shadow on his brain — it turned out to be the remains of a re-absorbed twin.
It always amazes me that, though we think if ourselves as a single person, our organs are all semi-independent of each other. You can have one organ be unhealthy or even die and have the rest be perfectly fine. If you get a kidney transplant, they don’t remove the faulty one(s) unless they’ve died (gone necrotic). They just pop a third one in there and you’re ready to go.
J R in WV
When you write “I do believe that “the universe is not only stranger than we know, it is stranger than we can know” I think you slightly mangle the quote.
Some one (I thought Einstein, but after trying to research it, maybe not) said “Not only is the universe stranger than we imagine, it is stranger than we CAN imagine!”
Mixes of DNA, and the recently discovered importance of colonial bacteria and other microbes lving inside and along side of us, make life almost unbelievably strange. How fun!
@Mnemosyne (iPhone): One interesting viewpoint is that it is an evolutionary advantage to mental functioning to have an organism consider itself a single functional unit — i.e., that our (and other creatures’) perspective that we are an individual rather than a collection of functionally cooperating sub-units is that it makes decisionmaking much more rapid & coherent. That this viewpoint, in other words, may be the result of evolutionary action, not simply our inappropriate philosophy.
I hope so. I was out to a rural middle school yesterday, for work. It’s in the middle of nowhere. It’s tiny. I get to the door and they have this new doorbell/intercom “security” thing installed, I swear it came from Ace hardware, and someone is coming out and she holds the door for me. It’s not that I mind her “defeating the security system”, it’s just that the whole thing is so pathetic. Connecticut had a security system. It didn’t matter. They may as well prop the door open. That at least would be honest.
You just get to where you’re like “we’re insane and I’ll just have to adjust”.
I mean no offense, Anne, but there’s something that really bugs me about that phrase. I only hear it from other people whose “eyes glaze over” at the sight of math. Similarly, that Shakespeare quote about there being more than is “dreamt in your philosophy.”
Maybe it’s because it subtly discourages inquiry. After all, what’s the point, what with all the unknowableness?
That said, chimerism is the coolest. It’s only going to interfere in DNA-based convictions where a fraternal twin or a person’s offspring is also under suspicion. And cancer and other genetically dependent diseases will mostly still be predictable or treatable using info about a single genome. Maustly.
I presume this explains why dogs and owners begin to resemble each other after years of being together.
Well, the world is always full of stupid. Even with The Flynn Effect, the smarter people are always going to feel the heat from the Friggin’ Obvious.
And the Intelligent Design folks will insist that this is WAY too complex to have happened without a guiding hand from the Designer-in-Chief..
I always assumed there was an implied “at this time” at the end of the sentence, meaning that as we do inquire, our capacity ti understand and imagine grows. Today’s commonplace is yesteryear’s unimaginable.
Since we are all the product of intelligent design, the inescapable conclusion is that The Baby Jebus decrees that a robust regulatory climate is Right and Moral. Thus, unfettered-free-marketeers and glibertarians are followers of Satan.
We’re in the early stages of understanding human Biology and most of what we know turns out to be partially accurate. Recent proof that glial cells act as neural signal transmitters alongside neurons is a good example.
As a father of twins, I read up on a lot of pregnancy/twin stuff a few years ago. There was some European study which concluded that perhaps 1/8 of people had a twin in the womb with them which withered away. (Not sure what fraction had some of the absorption go into the other twin, vs just back into the uterine lining/mother.)
Sister Rail Gun of Warm Humanitarianism
@Marmot: Different circles. The people I usually hear it from are intensely curious about everything and use the phrase as an expression of awe in the face of a new discovery.
Take your copies of “The Selfish Gene” and “The Naked Ape” and throw them in the trash can. Both are ludicrously obsolete and harmfully so when considered in the light of current knowledge.
Adding: the words “cooperation” and “competition” are meaningless at the level of molecular biology.
@Anoniminous: Here’s something weird: much of the information being transmitted by neurons may not be in electrical or chemical form, but as sound (in mechanical form as that of solitons–coherently traveling vibrational wave pulses–traveling on membrane surfaces).
A fascinating thing to me about this is not the very specific question of whether or not this is ‘the’ method by which neurons communicate. (Because the answer will be whatever scientists can best endeavor to conclude, so I’m obviously just a passive observer.)
It’s that it hardly seems likely that evolutionary opportunity would leave such a useful mechanism of transmitting information efficiently untouched.
@Anoniminous: I should clarify: I added the last bits mainly for entertainment purposes to tweak propertarian / ‘Objectivist’ weirdoes, and not in this context specifically as a ‘scientific’ sounding argument.
Of course, I thought that a limited interpretation of the ‘Selfish Gene’ metaphor was helpful rather than a drastically large statement. I.e., a mental tool of investigation, in which someone thinks about some evolved feature or problem and wonders ‘what options would be to the direct mathematically probable interests of a gene if conceived of as an actor’.
To me I always (I think, or at least at some point came to this view) saw it as a tool of thought, a conceptual tool to be used in considering evolutionary questions, and not as some systematic law-like rule telling us the formula of evolution.
I also bear in mind the context — at the time of its publication, there didn’t seem to be commonly encountered arguments in which there were other evolutionarily important methods of genetic and epigenetic and metagenetic transmission of information within, between, and to the next generation of organisms.
Still, what’s important is to bother the propertarians and ‘Objectivists’ who confuse a badly overacted appearance of harsh reality-mongering as reasonable thought [or even] as ‘science,’ sort of pseudo-scientific cargo-cultists who think if you dress up in lab coats and say cold and functional-sounding things about one’s own interests and about what is logical, then, by gosh, you’re a scientist!
(That said, they’re manipulative idiots who wouldn’t seriously reconcile the reality of our collective co-evolving evolutionary nature as colonial organisms, they’d just label it so that it fit with their ridiculous pseudo-scientific metaphor system.)
@El Cid: Oops: link to article discussion here.
I’ve often wondered about how the doctrine of ensoulment at time of conception is reconciled with the existence of chimeras. Any scholars of Catholism who know how this works? Do chimeras formed from N>0 fertilized eggs have N souls? (Twinning raises similar questions.)
@Bill Arnold: I’m sure they will get around to it in a few hundred years… you know, about how long it took for them to admit Galileo was right. And it took actual space flight and some “let’s be sure about this” decades to get there.
@Big R: Actually, I was only being half-funny, as any man who has had to deal with child custody can probably attest. But I get your point :-)
Those words are, at all levels, merely analogies; stories we use to describe the cumulative effect of large numbers of individual events.
The stories lose value when people try to do logical reasoning with them.
Your first comment was interesting. I’m going to have to track down the papers and see what’s going on.
Ref: linked comment
There was (and is) a well-ignored alternative to “The Selfish Gene” and the whole “Nature red in tooth and claw” mob: Kropotkin’s “Mutual Aid.” Darwin got the basis of his ideas from the Galapagos Islands and islands are a life-boat ecology. Kropotkin studied in Siberia where the ecological interactions are not as bounded. Using the Galapagos as “The” paradigm for All of Nature is as as absurd as using Vanuatu as “The” paradigm for All of Human Societies. Yes, under extreme ecological pressures species will strongly compete for food. Normally, however they don’t; they are more concerned with warning each other about predators – “The” classic example of mutualism.
I have found Objectivists, et. al., to be laughably ignorant of Biology in general and Evolution in specific.
I am sympathetic to your argument. Looking at the notions of “Message” and “Narrative” is a bit of a hobby of mine.
However, I am unsympathetic-to-hostile to people who take ignorance as knowledge and squish everything into avoidable vacuous blather because they cannot bother to get edimacated. See the ‘Social Text Affair’ for an example.
@Anoniminous: I always felt like that was something of a bum rap, or at least, more akin to punching down than punching up. Social Text was not one of the worst offenders in the pomposity wars by the post-modernist ways. Yes, they certainly should have avoided publishing Sokal’s hoax paper, but they were fairly innocuous, and had otherwise not (at least to my recollection) taken a ‘position’ as it were on the whole reality versus ‘the text’ thing, and I wish Sokal had targeted much bigger egoes. That said, at least the point got made.
Colonial? Typical anti-Tea Party bias, you Redcoat-lover.
@Anoniminous: I’d like to somehow feel I could rise above it all, but over time I’ve come to recognize how dependent we are — because the subjects are so hard to tackle — upon large-scale metaphors like “competition” etc., just to have some sort of handle upon knowing what you even might need to be looking for.
It’s easy to look back and see others’ blinders, but when I ask myself to think about how to research with no overlay of an evolutionary theme in humanly-relatable terms or with a better one, it sure is difficult.
@Hob: Well, duh! I meant before the Declaration of Intracellular Independence, before the War of Molar Aggression.