http://www.sciencedaily.com/releases/2013/01/130113201136.htm
Getting more info out of little remnants.
Jane just got her genographic report: it’s interesting—it’s her MtDNA from way back, and I’m waiting on pins and needles to know mine. She’s got relatives all over, including Siberia…way back.
hehe…..I wonder which way Jane’s ancestors came to North America, through the traditional way across the Atlantic, or across the ice bridge over the Bering Strait.
😉 Clovis Point technology is also found in France. There’s an hypothesis that they could have worked the edge of the sea ice across the Atlantic Ocean during the last Ice Age.
Probably both. 🙂
Interesting how much is in our DNA for physical makeup, mental abilities, versus how much is shaped by learning, environment, food, experiences. Also how much might be shaped by the time in utero, in the womb.
I suppose this will ultimately mean they could pop a DNA sample into a scanner and do a forensic reconstruction that way, right down to skin, hair, eyes, age, height, weight, the works.
Or, someday, pop a DNA sample in a scanner and order up a clone. Or a gene-tailored human with whatever characteristics were wanted. Could be fun, could be unfun, depends who uses it for what.
But it could also answer things like paternity and ancestry, which groups are related to whom.
Sidestepping the thornier ethical issues that have been discussed around for a long while —
What if it turns out there are more things in eye, hair, and skin color (or pattern) than show up “in the wild” in humans? Or ear shape? (Pointy ears for elves, anyone?) It could be a new fashion trend. (I know I’ve read stories with people cosmetically gene-tailored.)
Hmm, but you’d have to be very careful about that new pickup line: “Hey, hot stuff, what’s that in your genes?” 😆 Certain guys and girls might object. Others might be intrigued. I dunno. (BCS is not known for trying clever pickup lines. Perhaps one can see why….)
Consider this: nuclear DNA is, well, nuclear. At least when cells divide, the paired, coiled and wrapped chromosomes uncoil, unzip, get copied into a tetrad, then divide. So far we don’t have evidence that it gets copied one gene at a time on the spur of the moment in response to some extra-cellular environmental influence. What do genes do? Simply put, genes are the “parts lists” to make specific proteins, generally if not exclusively enzymes. That’s it. Adaptation happens elseways.
Likewise, it should have always been clear (was, to some), and is now generally accepted, that all that “junk” DNA would have been lost by deletion mutations if it weren’t actually necessary for existance.
The end result, rather too much has been made in the media of the controlling influence of genes. “Instigators” of biological processes perhaps, but far from the last word!
Genetics is a lot of fun, but it certainly isn’t SIMPLE. I’ll admit most of my upper level genetics classes were 20 years ago, so exact details might be a bit fuzzy, but I had a pretty good grasp back when. As far as telling what a person LOOKS like, its not as easy as saying “he has the gene Q, so he was blond.” There are usually different contradictory genes present that control the same phenotype (say, haircolor) and just because they’re all present, it doesn’t mean they’re all turned on. And different ones can be turned on in different places. That’s how we get hair that can have strands that are different colors. For example, I have mostly brown hair, but I’ve also got (ok, hush about the dang grey, ok?) individual hairs that are blond, others that are red, and even a few stray black. And just to make it more complicated, as we age different genes can be activated and turned off. As a child I was very blond, but now, not so much. That’s without even accounting for dominate genes and recessive genes! So, looking at the DNA lets them make a good educated guess, but its not going to be 100% accurate. You’ll notice most of the scientists usually hedge their bets by saying ‘was PROBABLY blond’ 🙂
Actually, Jane and I both know how our ancestors got to the Americas—and in a few cases, why it was a really good idea at the time. The English Civil Wars played a big part in it…our folk would have been on the King’s side, Catholic, and anti-Puritan; or Quaker, and anti-Puritan. We each do have a few Puritans in the family tree, if you can judge by personal names like “Thankful Doak”, “Wrestling Smith,” and “Obedience Turpin.” But these were very brief. I’m amused that Jane’s family, while New Englanders and prone to Biblical names, picked a Biblical name like “Bathsheba”; and Shakespearean ones like “Prosper Fitch.” How did we get here? We were running for our lives from politics, religious nuts, and governmental upheaval. One of my lines had a 200 year history of backing the wrong side. Jane’s folk were usually educated, doing things like pharmacy and inventing steamships. Mine were in local militias and trying to get commissions in the British Army in the colonies. But none of that shows in MtDNA. We do know Jane’s folk came literally from everywhere, and I’ll be real interested to see if I also have Denisovan (Eastern) ancestry: if you go into the iffier part of my ancestry, I have Goths and Visigoths, which came out of the East. That’s going to be an interesting question. We turned our genetic samples in via the same mailing; but she has her results and I don’t have mine. Wah!
And in the crazy way of things—my results just came through. Jane and I are the same haplogroup descent down to the last step. We’re both H. I’m H5B and she’s H3h2. We both have admixture of Neandertal and Denisovan, but her level of both is a tenth of point higher than mine. My folk weathered the Ice Age on the southern end of the Black Sea, not to leave it, apparently, until the thaw, when my group migrated across the mountains into what’s now Albania and on into Europe; and also northward toward Finland,which surprises me; and hers were further into Europe, over toward Southern France, Italy, Spain and Portugal. This is going to be interesting—prehistory is very soft-tissue; but Jane’s haplogroup concentrates in a place perfectly consonant with her genealogy; and mine offers a couple of surprises—that while I’m very European, my remote ancestors weren’t European until the ice melted; and then some crazy bunch, instead of chasing warm weather, evidently liked it cold—they apparently headed for Finland. Hunters, I’d bet, going where the fur grew thick. Which amuses me. Some of my longer Scandinavian lines try to go back to the Frost Giants. Maybe they weren’t as crazy as you might think. And Jane’s got ties apparently deep into pre-Frankish, pre-Roman Europe, which would also make a certain sense: she’s got a deep (much later) Spanish connection…if you go by the genealogy. Hmmm. This is going to spark some interesting conversation on long driving trips.
I’m H1a1.
This genetic stuff sounds quite interesting! Where do you go or who do you contact, or what do you do to have that DNA stuff done?
I thought that mitochondrial DNA, which is passed down through the maternal line, would have less “distortion” than any other DNA in the cell. Since “daddy” contributes some DNA, but not mitochondrial DNA, it would be free of that pesky “maleness” factor.
I’m going to do an edit on this one, where I fuzzily wandered off on the topic of regular DNA. Thank you, Weeble, Paul, and others: let me see if I can make this clearer, so I don’t lead you down a scrambled path from the get-go.
A woman can only do MtDNA tests, which will tell you where you came from 50,000-5,000 years ago—it’s not good on ‘is Gramma the natural daughter of George Washington?’ OTOH if you want to trace who you are deep down, a woman can get that test done.
A man can do either the MtDNA or the Y-DNA test. The Y-DNA test can tell a man he is the son of George Washington. Why? Because the genetic makeup of a woman is (barring some genetic quirks) XX, and a man’s is XY. A woman, definitively, is all X.
(This is why, contrary to Henry VIII’s personal beliefs, it is not the woman who determines the sex of a child: it’s the man, who can contribute EITHER an X or a Y. The woman can only contribute an X—either an X from her mother’s line, or an X from her father’s line. She does not have any Y’s to give.)
This is why Mt-DNA is less specific about parentage…but good on identification—because your MITOCHONDRIAL DNA is in the egg case, so to speak, and be you male or female, you get that (normally) ONLY from your mother. Your X’s can come from either side of the blanket, and in every mating, your offspring only gets half your set—but you don’t know WHICH X…just that they get AN X. A man only has one X to contribute to a daughter (not a son!) but whether that X came from his maternal or paternal grandmother is an increasingly wide ‘whether’. It is, however, a dead certainty that he got his Y from his father, and that if he has a son, that Y is going to be HIS contribution to the new son, NOT an X, which would create a daughter.
If the operation of ‘regular DNA’ confuses you, line up a genetic chart with a dime and a penny beside every male and two dimes beside every female, and look at what happens if they have to create a child. Only dimes—female. Pennies are rarer—and if a penny comes from papa, you can bet papa got that penny from grandfather, who got it from his father, on back to Charlemagne, with a few dings and nicks from accidents and mutations along the way.
Mama ONLY gets dimes from her parents. Papa gets a penny from his papa and a dime from his mama. But WHICH of mama’s two dimes is she going to give to a daughter—or a son? She has a choice. Papa doesn’t. Penny makes a son; dime makes a daughter. No monetary value implied.
NOW: the MtDNA, which is an analysis of the dna of the mitochondrial bits that came with the egg: these bits do mutate more often than regular DNA. And the mother theoretically only this one type to contribute—but it has ‘vintage,’ ie, it will pass from mother to ALL children, like, say, eggshell; but since mutations do happen more frequently and create new identifiable groups of descendants, the females of which who pass on the mutated ‘eggshell’, they will be scattered all along the migration route of her ancestors. A man can take this test and get the same sort of information about the MtDNA his mother gave him, which is (should be) identical to her grandmother’s grandmother’s. Unless there was a mutation. If the mutation happened in what he got—it won’t pass on. He can’t pass on his MtDNA (under normal circumstances). His daughter will have HER mother’s MtDNA. But his sister, if she got a mutated form, CAN pass it on.
What the Y-DNA test can tell a man is where his particular penny (father’s contribution) came from, in specific, and which specific individuals have owned it, throughout all of history…so long as you can get genetic material from the spit or bones of the male progenitors involved.
So both tests give you information: remember you have a whole cartload of other chromosomes, besides just X and Y. And what they test with MtDNA is that part of your genetic information that governs the ‘power pack’, or energy-producing element of the cells. From WIKI: “In humans, *mitochondrial DNA* can be regarded as the smallest chromosome coding for only 37 genes and containing only about 16,600 base pairs. [Trust me: this slims down your choices a lot] Human mitochondrial DNA was the first significant part of the human genome to be sequenced. In most species, including humans, mtDNA is inherited *solely from the mother*—that’s why it’s useful. This structure provides the energy for all cells in your body. But male or female, you get it only from your mother (because it comes with the egg). People are divided into ‘haplogroups,’ kinship groups based not on eye or skin color, but exclusively on the characteristics of only one trait: the dna information of the mitochondria.
Now—the DNA bit that gives you male features is exclusive to males—and it also is a pretty small snippet of genetic code, again from WIKI: “A man’s patrilineal ancestry, or male-line ancestry, can be traced using the DNA on his Y chromosome (Y-DNA) through Y-STR testing. This is useful because the Y chromosome passes down almost unchanged from father to son, i.e., the non-recombining and sex-determining regions of the Y chromosome do not change. A man’s test results are compared to another man’s results to determine the time frame in which the two individuals shared a most recent common ancestor, or MRCA, in their direct patrilineal lines. If their test results are a perfect, or nearly perfect match, they are related within genealogy’s time frame.”
If you are a female who wants to know about your patrilineal descent (which is more specific than the female and can more accurately point to specific ancestors)you have to get a male relative, ideally a brother, father, or grandfather, etc, ie, the closer the better, who has a paternity you believe, to take the test for you.
Actually, mitochondrial DNA even simpler than pennies and dimes. The mtDNA is just a snippit of very specific DNA floating around in packets (mitochondria) in the main part of the cell, outside the nucleus. HALF of the rest of the DNA that makes hair and fingers and eyes and such is packed into in the nucleus of the egg cell. Sperm are basically just a packet containing half the father’s nuclear DNA, they don’t have any mitochondrial DNA at all. When the cell divides, that packet of mtDNA copies itself so both new cells have exact copies. It chances very very little from mother to child, so its easy to trace. Nuclear DNA changes a lot from parent to child, because of the mixing.
That pesky Y chromosome is an oddball, because there’s only one even though its in the nuclear DNA mishmash, and it has nothing to mix with, so it can be traced too.
Thank you, Weeble—well and clearly stated! What I was trying to express is that most of what most people who purchase the DNA tests THINK they’re testing is actually not what they’re testing; and what Henry VIII thought happened in the production of a child isn’t what happens.
Okay, okay, I just have to chime in here with a quotation from Bill Cosby. Now, Bill had a routine in which he described his daughters, and how he had wanted a son. “Now, I know that the father contributes the X and the Y chromosomes. But I believe whoever had it last is to blame!”
One point: Though what CJ and Weeble said is correct, the impression might be that males are rarer. But in most large human populations, it’s nearly 50-50, the number or proportion of males and females is close to equal. (It teeters by a couple of percent plus or minus, in practice.) In smaller, limited populations, though, it can become nearly all-male or all-female, but that’s more by custom and gender roles. Over time, though, the proportion of women to men increases. The males tend to fall to accident, illness, or injury, more often than women. That’s also partly due to custom and gender roles. Arguably, it’s also due to biology, whether being male and all those male hormones make a male more prone to risks, violence, etc., but how much is truly biology and how much is cultural expectations/upbringing (for men and for women) might vary some. Note also, humans have low “sexual dimorphism,” meaning there is not so great a difference between males and females in humans as there is in other species. This means that despite cultural beliefs, there’s a lot of overlap in males’ and females’ physical and mental capabilities. The differences tend to be in the styles, the way we go about things to arrive at a solution, and in cultural influences. Though there’s some biological factors in there too. (I’m not arguing in favor of either biological or cultural determination of male and female capabilities. There’s feedback, complex interaction, on either stance.)
Or Thos Jefferson, eh? 😉
It’s said there are an estimated 6 million men in Central Asia with identical Y chromosomes by descent.
@BCS: There are statistically more males conceived, fewer born. It’s thought that because the Y chromosome is smaller, the sperm isn’t impeded as much. But our mothers immune systems may see any male cells leaking through the placenta, and attack us! “Hey, Mom! Take it easy!”
Just as a point of curiosity, my friends, there are only thirty or forty generations between you and ancient Rome, and by that time you are related over and over and over again to everybody within mate-seeking proximity. If you are not personally related to Charlemagne, you know someone who is. If you could trace your ancestry back to the reign of Amenhotep, the number of your ancestors, if you were not crossbred continually, would exceed the population of planet Earth. I have a pretty good record, and I *know* my ancestors are crossrelated as all get-out even in the USA, where my maternal and paternal lines both have Boones of separate generations (there were no cousin marriages) ergo some of my lines are Xeroxable—highly so. And cross with Jane’s. It’s all in the family.
IIRC, and correct me if I’m wrong, isn’t the “Mitochondrial Eve” supposed to be essentially a contemporary of Lucy the Australopithecine? I suppose it gives a whole new vibe to, “the warm fuzzies.” 🙂
I recall there was an estimate of how many generations back to the last Ice Age, and then back to the Australopithecines. I don’t recall if there was mention of how many steps, generations, back to the Bronze Age.
From what I recall, I want to say that the number of generational steps back to each point was considerably *less than* one might first guess, meaning that there’s more relation between any two people than we would expect offhand.
I’d suppose it’s also likely that once we get back to the 1700’s or earlier, the number of years between a generation decreases. That is, a couple gets together and the mother has a baby, with both the father and mother tending to be younger as you go back in time. There were, of course, plenty of exceptions, and even in the 1800’s, as long as you were lucky enough to live to late teens or early adulthood, you might live anywhere from your 40’s to 90’s, depending on further luck and good genes, barring sickness or injury, fighting and wars, or natural disasters.
Though I’d also have to say there’d be notable exceptions to the rules, often enough, so that a man or woman might be likely to have children as long as physically possible.
Be it noted, too, that the ability to produce a child would vary per person. Given health and nutrition variances, they might be anywhere from terribly young, 12 or 13, to nearly 18, before being physically capable to produce progeny. But it was common enough within many cultures for marriage customs to allow marriage at 13, for girls or boys. If they were indeed capable yet and producing children at that age…. Whew, but it would be just as risky and stressful then as for teen pregnancies now. Add to it that most cultures didn’t have too clear a notion how to avoid pregnancy or sometimes what caused it…. Just, wow. Even though adult responsibilities came earlier for early people, somehow the idea of being a father or mother as a teen back then, when so much was a risk, and when they are not really grown yet themselves…. Mind-boggling. And yet a lot did. — But there were also social controls that tried hard to prevent any opportunities too early to make babies, 😉 and to provide marriages with some chance of maturity…maybe.
Gah, it’s a wonder anyone made it through safe and sane, to raise families.
That depends on how you judge that you’re testing “human” ancestors. Where’s your horizon? I’ve heard that cladistics traces MtDNA back to 5 separate “Eve’s”, thought to live in SW Africa. But that can’t tell us they were necessarily all “Homo something” except by presumed mutation rates per millenium.
My Dad’s Grandmothers were second cousins, maybe once removed. Goodbars.
Oh, King Peter I of Spain I mentioned? His parents were double first cousins! He only had four great grandparents.
I’m curious how you get tested too. My American ancestry on my dad’s side stays essentially in one area going back to about 1828, and from that, back to 1755 when they got to the Colonies. Ethnically, on both sides, I have English, Scots, unsure about any Irish, German and/or Dutch, and Native American, Cherokee or allied most likely. Going back to Europe, I’m not sure beyond clearly a lot of Northern European ancestry. My dad and his siblings all were white-blond, tow-headed kids whose hair darkened around their teens, except my uncle, who’s blond like me. All four of my grandparents had blue eyes. It turns out that pale hair and complexion is probably the source for my last name, and medieval folks tended to think that such features might make you a changeling or friend of the elves, and thus good or bad depending on what you thought of such.
Going by family name history is iffy, especially since my last name is unusual, linguistically. It’s either a dialectal variant from Northern England near the Scots border, quite Anglo-Saxon, or else it could be similarly dialectal from Dutch or German sources. The genealogical evidence upon arrival in the American Colonies isn’t too clear either. The two brothers were Phillip and either John, Johan, or Johann, depending on who wrote what, and perhaps how eager they were to embrace the new colonies, which were about half English and half German by speakers. There was my paternal grandpa’s opinion we were “German Dutch”, but this may come as much from a lot of a German or Dutch set or relatives back in the family tree as from the family name itself. That “German Dutch” thing stems from a common misconception back around the time of the American Colonies; compare “Pennsylvania Dutch.” (Those ancestors of mine moved from Pennsylvania down to Virginia.) Dutch and Deutsch (German) combined in the early English mind to the same thing. It didn’t matter that it might be really German speaking or really Dutch (Holland, Netherlands). To early English and American minds, it was the same.
Add to that, something about my last name doesn’t compute for most people, even now. I once stopped counting at twenty different misspellings currently for me. Yet it’s only one letter off from a common English surname. Throw that in with non-standardized spelling in the Colonial and Frontier eras, and oh boy. However, my dad’s line appears to have been literate, probably going back to those two brothers, but at least into the early 1800’s. Literate, though, didn’t mean you could spell consistently, even if you were educated, and certainly not if you were a farmer, craftsman, or even a county court clerk recording official records. But early on, my people decided how to spell their last name and stuck with it. A lot of them, my grandpa included, had “itchy feet” and explored, going out from Virginia, Tennessee, and Kentucky into places like Kansas and California to settle. There are both white and black folks with my last name, but at least my own branch didn’t seem to be slave owners. Even so, those county records might count estimates as to the number of people and livestock at a given point of record, and unless it’s specifically listed that there were slaves, well, you aren’t always 100% sure. So it goes.
For an indication of how much early people might travel, take my grandpa again. He had a one-room schoolhouse education. He and grandma taught their kids reading, writing, and arithmetic before they got to the local school. So despite that the two had at most up through what we’d call high school educations, if that, they were doing well for farmers. Well enough that my grandpa did surveying and helped others with legal contracts. He wasn’t a lawyer, of course.
The family would go into town or to the county seat regularly for supplies and to sell their produce and livestock. They cooperated with neighboring farmers. Everyone had to or you might not make it through the winter. But people knew each other. The area was settled back into the Colonial period. Along with this, my grandpa might travel, on foot or horseback or wagon, anywhere in the surrounding area, several counties in three states, because they were right near the tip of Virginia. Both my dad and my grandpa had excellent memories for things and people. So my grandpa knew friends and relatives, trading partners, whoever, from all over the place for several counties, and he often knew something of their family histories, and the history of the area. He had “itchy feet” to the extent that he and a sheriff friend/relative would travel by train elsewhere in the state, and my grandpa made visits to Texas, Kansas relatives, and out to California. (I didn’t know until later, not only was there a friend he met, but there were others, distant cousins, out there.) My grandpa liked Texas so much that he moved the family back and forth at least three times, but he always missed “up home” and moved back.
The upshot of all that, is to show that even with only horses or feet for transportation, even supposedly settled farm folk might regularly travel and visit in an area of a few hundred miles, not just about twenty or thirty miles. Not everyone might be that ambitious all the time, but it was often enough, both for trade and supplies, and for keeping up with friends and loved ones.
—–
Now if you had people living as nomads, always traveling, foot or horseback, living in tents, you could conceivably go at least twenty or forty miles (more?) in a single day. Add that up, and in a season or a year, you might go from one end of the continent to the other. Now if you spend an evening with someone who takes your fancy, all of a sudden there may be progeny all over the place. 😉 (We’ll suppose that it could be a marriage worked out over a period of months or years, just as much as it might be a short affair, an evening, or ah, as long as it takes to, er, do what comes naturally.)
We’ve pushed some lines back beyond 20 greats to Edmund of Langley and Peter/Pedro I of Spain. And Charlemagne is back there too. But my admixture test says 12.8% Uralic, and sure enough we’ve a GGF we can’t trace. (Hungarian is most likely I’d guess.)
IIRC, there’s a line in Bell’s Men of Mahematics that Gottfried Leibnitz’s profession was geneaology, “proving his clients deserved titles to which their ancestors had neglected to fornicate them.” If the King thinks he’s descended from Julius Caesar, you’d better prove it! 😉
Here is a question? Not much is mentioned in the Foreigner books concerning medicine or medical research.
Suppose the Atavi started doing DNA analysis. Would common ancestry effect Manchi? Would you become loyal to whoever merely on learning that you share a certain percentage of DNA?
On the other hand, since this would be a new technique, probably from the hated Mospheriens, it might be merely condemned. Or would it?
Man’chi is more emotional, and possibly to some extent pheromone-driven. So it’s possible one might be attracted (or repelled) because of inheritance.
If genetics offered new ‘numbers’ by which to understand the universe, it would create a storm of interest, and no little confusion.
Easy peasy. Once we come to a “Start” codon, also used to code for Methionine, the base pairs are taken in triples, 4x4x4=64, which is a large enough number of combinations to account for the 22 different amino acids used in protein synthesis. It’s more than enough, so the code is “degenerate” with synonyms. (No doubt they’d find mysteries there!) (Including 3 “stop” codons which mean only that, as opposed to the “start” codon.) So the genetic/protein code can be read off as a sequence of numbers from 1 to 64, or 1 to 22 with some mysterious significance to which synonyms are in someone’s code. Of course, this is the basis for the haplotypes.
And then we consider topology to be a branch of mathematics, if different than numerology and number theory, but that could lead them into the important study of protein folding.
If DNA codons are a base 64 numbering system, 64 combinations can encode 52 upper/lower case English letters and some punctuation. Did so in the 50’s with the BCDIC code used on old second-generation computers! So now the Shakespeare sonnets have been encoded in DNA! (Reminds me a bit of an old SF story, “Say it with Flowers” IIRC, about smuggling a surrepticious message.)
http://www.npr.org/2013/01/24/170082404/shall-i-encode-thee-in-dna-sonnets-stored-on-double-helix?ft=1&f=1007
Getting more deeply into the MtDNA question—it’s really interesting to look up in WIKI—they’ve discovered quite a bit (obviously!) recently, and the MtDNA stuff is no exception. There is, as I was assuming, interference in the MtDNA *by* the incoming meiotically-derived male contribution…but it happens within the fully-functional cells throughout life of the organism: ie, when the mitochondria (the energy factories of cells) call for certain chemicals, the regular-DNA part of the cell may, through inheritance, be unable to deliver—this can produce serious genetic disorders, motor difficulties, etc.
But it gets more complicated than that: you DO receive your mitochondria solely from your mother because the paternal mitochondria, in the sperm, are in the tail, which is supposed to fall off and not enter the egg. But in in-vitro fertilization—it doesn’t. Oops.
And MtDNA mutates more than regular DNA —not hysterically fast, but often enough. That’s what makes it useful as a time marker and why the MtDNA along one migration route is different than MtDNA down the course of another, sort of like watching stained water, as in watercolor, change in intensity as it runs along the paper, or picks up a speck of stain it didn’t have before.
It can be used in identification, particularly in old remains. The tsar’s family was identified by it; so was Jesse James. The deal is—it can EXCLUDE somebody, and given other known details of the person and circumstances of burial, it’s possible to say two individuals are related, because while the MtDNA is the same in every brother and sister with the same mother, and again in every child of the sister—it’s NOT identical to the Joneses next door.
So you and all your sibs of the same mother have identical MtDNA, but due to the card-shuffle in meiosis, the mathematics of which produce a lot of variables, your personal DNA is different: if you (and 3 brothers) are male, the Y-DNA test will specifically connect you and your brothers with one specific father and grandfather and great-grandfather, etc. on the face of the planet in all of recorded time, sort of like a patronymic (name) that belongs to all of the males. The MtDNA will connect you and all your sibs with a group of people to which your mother, maternal grandmother, and maternal great-grandmother belong, sort of like a clan name that could belong to every descendant of these women, transcending the patronymic.
And that and all the rest of your DNA is busy turning off and on like little switches and running your bodily machinery throughout your life.
CJ, AFAIK I think that last sentence is doubtful. We are, as yet, unclear about how the “control functions” of the genome are “brought to bear”. It’s not clear exactly when transcription takes place, as your sentence implies. You could be correct, but I’m just not sure we know that yet.
http://en.wikipedia.org/wiki/Junk_DNA
p.s. I don’t think “doubtful” means “wrong”.
🙂 I’m not wedded to that idea. Everything is on post-it notes in my memory, where it comes to ‘how the genes do their thing’ or ‘how FTL is going to work.’ I’ll give you my best current theory. (Although NASA’s working on one that’s amazingly close to my post-its. :lol:)
The DNA is the blueprint, and as we develop, different genes are turned on and off. But the “junk DNA” changes the 3D structure of the DNA in a chromosome, so can affect transcription (DNA is transcribed to RNA). And many factors affect translation (RNA is translated into a protein, and the gene is expressed).
And then there’s the fun of epigenetics! Lamarck wasn’t as wrong as evolutionary biologists insisted. In one study involving several generations in Sweden (good old Wikipedia describes it: http://en.wikipedia.org/wiki/%C3%96verkalix_study, as does “Nature”: http://www.nature.com/ejhg/journal/v10/n11/full/5200901a.html), the researchers found that if the paternal grandfather had plenty to eat during his slow growth period (“the time before the start of puberty, when environmental factors have a large impact on the body”), his *grandchildren* had shortened life spans.
Wish I knew more!