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The Shallow Roots of the Human Family Tree 760

Posted by Zonk
from the easy-to-blow-away dept.
An anonymous reader writes to mention an AP story about research discussing the relatively recent origins of every human on earth. Despite the age of our species, every human on earth can trace their ancestry back to someone who may have lived as recently as the Golden Age of Greece (around 500 BC). From the article: "It is human nature to wonder about our ancestors -- who they were, where they lived, what they were like. People trace their genealogy, collect antiques and visit historical sites hoping to capture just a glimpse of those who came before, to locate themselves in the sweep of history and position themselves in the web of human existence. But few people realize just how intricately that web connects them not just to people living on the planet today, but to everyone who ever lived."
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The Shallow Roots of the Human Family Tree

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  • You might be able to trace your geneology, but the process assumes that all your ancestors were entirely forthcoming when it came to their nuptial reltaions. Makes you wonder why children take the male's family name?
    • by Peyna (14792) on Sunday July 02, 2006 @03:10PM (#15646636) Homepage
      Makes you wonder why children take the male's family name

      A: You live in a patrilineal society.

      Not everyone has live or currently does live in such a society. Arguably, matrilinealization is the more intuitive method, becase you can be pretty certain who is the mother of the child.
      • Indeed, Jewishness (Score:5, Informative)

        by Flying pig (925874) on Sunday July 02, 2006 @04:34PM (#15646935)
        is passed through the female line. As the Roman author had it, mater certus, pater semper incertus est (The mother is certain, the father always uncertain.)
        • by XchristX (839963)
          Yeah. Matrilineal and matriarchial societies exit among Tamils, Meghas (in North-Estern India), communities in Andhra Pradesh (specially Telegu Jews, who keep strict records of their matrilineage) etc.

          Surprisingly numerous, these matriarchials...
          • by Mistshadow2k4 (748958) on Sunday July 02, 2006 @05:31PM (#15647144) Journal
            This may be off-topic, but I wanted to bring this in context. It's not just "other" peoples who have been matrilineal. The Celts were matrilineal as well, and some notable families in Europe remained matrilineal even past the Middle Ages. Many, many Native American tribes are matrilineal. What changed this? Christianity brining decidedly Roman attitudes. So, if you have Native American and/or Celtic ancestry, your ancestors were matrilinral. That covers most people in the Americas and Western Europe.
            • by cwspain (774211)

              What changed this? Christianity brining decidedly Roman attitudes.

              Actually, not Christianity bringing Roman attitudes, but Romans. For the first few centuries of Christianity in Ireland and northern Great Britain, it had a distinctly Celtic flavor, including a greater degree of gender equality and married clergy. Some even believe that St. Brigid was a bishop (the evidence is not very strong in either direction). The change came when the Celts started sending missionaries to the European mainland and t

          • by the phantom (107624) * on Sunday July 02, 2006 @07:36PM (#15647520) Homepage
            Offtopic, but I feel it is important to point out that there is a great deal of difference between matrilineal organization and matriarchy. Matriarchy is where the women hold political, social, and/or religious power. In a matriarchy, the women are the primary owners of private property, and make the decisions that affect what the group will do. There are almost no examples of matriarchal societies in human history. That is not to say that a few have not popped up, but they are very rare and far between. On the other hand, a matrilineal society is one in which inheritence (of name, property, clan association, moity association, position, &c.) is passed through the female line. Generally, men are still in charge, but relationships are tracked by way of the female line.
            • by XchristX (839963) on Sunday July 02, 2006 @08:36PM (#15647653)
              I disagree with you that matriarchial societies are rare. In my country (India) matriarchial families (where women held positions of power) are not uncommon. They have been even more common in the past. Example is the Maratha Confederacy

              http://en.wikipedia.org/wiki/Maratha_Confederacy [wikipedia.org]

                which, while founded by Shivaji Raje Bhonsle (a man) was really run by his mother, Jijabai

              http://en.wikipedia.org/wiki/Jijabai [wikipedia.org]

                As well as the reigning queen of Jhansi, Laxmibai

              http://en.wikipedia.org/wiki/Laxmibai [wikipedia.org]
              http://www.copsey-family.org/~allenc/lakshmibai/ [copsey-family.org]

                in the 19th Century.

                Matriarchial societies were aggressively discouraged by muslim rulers after they invaded and occupied large parts of India, since, according to Islamic Kanoon-e-Shariat, a woman can't take a dump without the husband's permission. Despite that, the Mameluk dynasty of the Delhi Sultanate was briefly inherited by a woman, Sultana Razia al-Din (Jalalat ud-Din Raziya), daughter of Shams-ud-Din Iltutmish (India's first and last black emperor).

              http://en.wikipedia.org/wiki/Razia_Sultan [wikipedia.org]

                Of course, the mad mullahs got their undies in a twist over that, but she did rule for 4 significant years in the Sultanate.

                There is a strong matriarchial tendency in many Maratha clans in India to this day. Maratha women are aggressive and outgoing (more so than other Indian women). They bunch up their saris , wrap them around around their legs and wrap the tail over the backside and tuck it uder the small of their backs, making them more like trousers.

              http://www.maharashtratourism.net/images/women-wea r.jpg [maharashtratourism.net]

                This way, their movements are less restrictive. They can run, walk long distances, balance themselves better while carrying heavy loads, and engage in physical labour like their male counterparts. They are addresses as 'Bai' (meaning Lady) in public, they fish, farm, sell stuff, all that. Maratha women often contribute more to the family income than Maratha men.

              South Indian families (even Brahmin ones) often have the mother as the key decision-maker in the family (since males are busy working or studying) and thus has de-facto authority in family matters, even over the husband. This was true of my own grandmother, for instance (I'm Bengali), where my mother was one of 7 children, and my grandmother coached them in homework, got them to do chores, decided which schools they'd go to and so on, while my grandfather was busy at work (sometimes away from home for weeks). That's a matriarchial family right there.

                If you define power roles by the breadwinner, then these families are not all matriarchial, but that's a pretty narrow criterion in my opinion. The real power of authority is in the hands of the decision maker, which, in these cases, is the female, not the male.

                Plus, many South Indian Hindu Brahmins don't adopt their father's names as family names. They adopt the names of the town/village where their family originated (similar to some Arabs that way). They keep fairly detailed records of their lineage, and not much patriarchial bias exists in that process.
        • Somewhat misleading (Score:3, Informative)

          by sgent (874402)
          The Jewish religion is passed down through the mother. To inherit judaism, your mother must be jewish.

          That said, the religious status (priest/Levite, Cohain), tribe, and inheritance are all passed through the father. For instance, David was the scion of Saul. His mother was irrelavent to his being King of Isreal.

          • by Hepneck (876605) on Sunday July 02, 2006 @07:55PM (#15647559)
            Neither of David's parents were relevant to his becoming king. Jonathan was the scion of Saul, as he was Saul's son. David, the son of Jesse (and later Jonathan's best friend), was unrelated to Saul, and became king because he was annointed by the prophet Samuel. Neither David's patrilineal, nor his matrilineal line mattered to his being king of Israel.
            Your facts were wrong, your point is right.
        • by Colin Smith (2679) on Sunday July 02, 2006 @06:55PM (#15647426)

          http://www.childsupportanalysis.co.uk/analysis_and _opinion/choices_and_behaviours/misattributed_pate rnity.htm [childsuppo...ysis.co.uk]

          ok, it seems to vary from about 5%, but rates of 20% - 30% are common. So... Guys... have you had a DNA test?

           
      • by Cyryathorn (6591) on Sunday July 02, 2006 @09:40PM (#15647815) Homepage

        "Arguably, matrilinealization is the more intuitive method, becase you can be pretty certain who is the mother of the child."

        ... which is a good reason why family names get passed down patrilinearly! It gives the dad a stake in the life of the child, and it gives the child a claim on a particular father (even if it's the wrong one, biologically speaking).

    • by netsharc (195805) on Sunday July 02, 2006 @03:14PM (#15646649)
      If you go x generations back, there are 2^x "ancestors" (1 generation before you: 2^1 = 2 parents, etc). If we go back 5000 years then you have, hmm how many generations? Let's say 200 generations. 2^200 = 1.6 x 10^60, but there weren't that many humans back then. So it seems their research have concluded that a lot of people have a common ancestor. Is it in-breeding? Well, sort of. Going the other way, if you have 2 kids, and they have 2, etc, etc, you will have 2^x grand(-grand)*-kids that after e.g. 20 generations, a million people will be there, and it's hard to believe that two people will know that they are related to each other through you.

      Fun to think about..
      • Ye go back far enough, we are all cousins. Does't surprise me at all. People have been known to wander nomadically all over the European-Asian-African land mass for thousands of years. Getting around by boats has also been widely available and common since prehistoric times. I wouldn't expect to go back very far to be cousins with everyone in Europe, Africa, and Asia. And now that white folks have been mixing it up with the natives in the New World for several hundred years, I'm probably cousins with
      • by Anonymous Coward on Sunday July 02, 2006 @06:13PM (#15647283)
        If you go x generations back, there are 2^x "ancestors" (1 generation before you: 2^1 = 2 parents, etc).
        Not down South.
      • by forand (530402) on Sunday July 02, 2006 @06:13PM (#15647285) Homepage
        The problem with your idea of 1.6e60 people in the past is that you are over counting. Sure I have that many possible combinations but in the end there is only one line that made me. I find it is easier to think of it in the future instead of the past, i.e.: if I have 2 kids and all my later relatives have 2 kids then my genetic input to the species will grow by powers of 2 per generation. However at each point someone else is also inputing genetic info so at each point I have to take out a factor of two for the total of the planet, which is why, if we all only had 2 kids we would never have a growing population and everyone would be related to everyone else rather quickly, which is what they found. Now I am babbling. . . .
      • by elronxenu (117773) on Sunday July 02, 2006 @07:03PM (#15647446) Homepage
        The article fails to consider the Australian Aborigines, who crossed into Australia via a land bridge from Asia around 40,000 - 50,000 years ago.

        It's an interesting mathematical trick, but their result is so obviously empirically false, so I doubt their research even after excluding the Aborigines and other populations known to have been isolated from the rest of the world for many thousands of years.

        • by The Nordic Beast (975740) on Sunday July 02, 2006 @10:57PM (#15648014)
          The article fails to consider the Australian Aborigines, who crossed into Australia via a land bridge from Asia around 40,000 - 50,000 years ago. It's an interesting mathematical trick, but their result is so obviously empirically false, so I doubt their research even after excluding the Aborigines and other populations known to have been isolated from the rest of the world for many thousands of years. The parent gets the time period for the arrival of Aborigines in Australia correct, but is incorrect in asserting that they walked there over a land bridge. A no time during hominid history would you have been able to walk to Australia. The deep water trench between Bali and Lombock and between Borneo and Sulawesi (the so-called Wallace Line) marks fartherest you could have walked from Asia. Given there's generally been deep water between Timor and the rest of the eastern Indonesia archepelago and between Timor and Australia, the original Aborginies probably had to make three pretty sizeable water-borne leaps at a long before there is any archelogical evidence anywhere that people are using boats. This makes the mere existence of Aborigines in the Australia for that length of time is pretty astounding.
        • The article fails to consider the Australian Aborigines,

          The aborigines were not genetically isolated. Australia was visited by Indonesians at least 4000 years ago. We know this because that is when dingoes (dogs) arrived in Australia.

          • The perfect argument (Score:3, Interesting)

            by ynotds (318243)
            While there are other clues that any notion of extended periods of genetic isolation of Australia in recent millenia is misguided, the dingo argument puts that to rest. By the time of the British invasion, dingos had spread through out mainland Australia, but not Tasmania, which does at least provide an exception [slashdot.org] to Olsen's supplementary claim.
        • by Richard Kirk (535523) on Monday July 03, 2006 @07:45AM (#15649219)
          Various other people have come up with arguments saying that Australia was not isolated. They well may be right. However, Australian aboriginies were the example I first thought about in connection with this.

          We know, or we believe we know from genetical studies, that populations do migrate or diffuse out rapidly. Often this motion is along trade routes, or around shallow coasts; following animal migrations, rivers, or belts of arable land. As long as there are suitable links, then there will be patches of people with a common relation. In medieval times, Indian objects got to Scandinavia, and Roman glass fot to Japan. But we also know there are places like Australia which took a long time to be discovered by Europeans (they somehow managed to find Tasmania first, but miss Australia), and so are probably much more weakly connected with the rest of the world. There are also other cultural barriers that will attenuate if not prevent intercourse between races, countries, religions, tribes, and whatever. Genetic research has told us that these taboos have probably been breached throughout history, but nevertheless there will be resistance.

          We do not know nearly enough about where people did and did not travel in early history to make such a model. A lot of the evidence from 5000BC has probably vanished with rising sea levels. My gut feeling is that this model makes the world too uniform, and does not have enough hard links to it, but I don't really know either.

    • by Tatarize (682683)
      In a couple decades somebody is going to start a great project to just check people's DNA and plug them into a world family tree. The Y and mitochrondial dna would be great, we could probably trace anybody right to their family. Similar things are being done between species where DNA tests are providing actual relationships between animals as such. Someday we will be able to find a DNA sample and even if it's not in the database we will be able to find out exactly who his parents are.
      • by gEvil (beta) (945888) on Sunday July 02, 2006 @03:46PM (#15646777)
        In a couple decades somebody is going to start a great project to just check people's DNA and plug them into a world family tree.

        You mean like this? [nationalgeographic.com]
        • by jc42 (318812)
          From the Nat'l Geographic FAQ:

          9. What tests do you perform?
          We will be performing ONE OF two tests for each public participant.

          Males: Y-DNA test. This test helps us to identify deep ancestral geographic origins on the direct paternal line.

          Females: Mitochondrial DNA (mtDNA). This tests the mtDNA of females to help identify the ancestral migratory origins of your direct maternal line.


          So they will ignore all of the autosomes, and test only the tiny Y chromosome for males. Their results will only tell you about
      • by wfberg (24378) on Sunday July 02, 2006 @03:50PM (#15646793)
        In a couple decades somebody is going to start a great project to just check people's DNA and plug them into a world family tree. The Y and mitochrondial dna would be great, we could probably trace anybody right to their family. Similar things are being done between species where DNA tests are providing actual relationships between animals as such.

        The entirety of the population of Iceland has been DNA-sampled and indexed according to their lineage. DNA studies are already used to determine how populations moved and intermixed in the past, on a population-wide scale (where a few people from a population are sampled, rather than everyone).

        There even a (if somewhat shaky) DNA test to determine racial descent [raceandhistory.com]. I saw it on a TV show once, where they had some school kids find out they had DNA from basically another race. I.e. a black guy turned out to have some asian genes, a white girl with blonde hair turned out to have some black genes etc. Possibly a bullshit test, possibly not.
  • Example: the native population of Tasmania, which had been isolated for 10,000 years - although there might not be any "pure" Tasmanian people left.

    Other than that, the artocle does make sense.

    • by tetromino (807969) on Sunday July 02, 2006 @03:12PM (#15646645)
      What population? The were white settlers hunted the Tasmanians down like animals, then herded the last few survivors to a Christian-themed labor camp on a desert island where they succumbed to starvation and disease. The last pure-blooded Tasmanian died in 1876. Her skeleton was put on display in the Tasmanian Museum (as an example of "primitive human") and was finally cremated, over the museum's vehement objections, in 1976.
  • Er, what? (Score:2, Insightful)

    by Aladrin (926209)
    Relatively recent origins? You mean, like, everyone on Earth today was born within the last 125 years? Duh!

    Oh, you mean ancestry... Yeah, every dates back to the monkey-that-wasn't-a-monkey having babies. Duh.

    More recent than that?

    OH! Maybe you mean: Everyone is connected by a common ancestor a LOT more recently than people think is possible!

    Maybe you just should have said that.
    • Maybe you mean: Everyone is connected by a common ancestor a LOT more recently than people think

      Thanks. The summary made no sense whatsoever - it made it sound like people were spontaneously appearing in Greece around 500 BCE.
    • Better links (Score:4, Informative)

      by Alien54 (180860) on Sunday July 02, 2006 @06:14PM (#15647289) Journal
      First there's this story about

      Genealogists discover royal roots on every family tree [physorg.com]

      In which they discuss the royal roots of Brooke Shields.

      What is it about Brooke? Well, nothing -- at least genealogically.

      Even without a documented connection to a notable forebear, experts say the odds are virtually 100 percent that every person on Earth is descended from one royal personage or another.

      then there is this old link to the notion of the Most Recent Common Ancestor of Mankind [humphrysfamilytree.com].

      The huge number of proven descents of people from common European royal ancestry in historical times, when considered with the vastly greater number of descents that must exist but are not among the rare few that can be proven, suggest strongly that everyone, in the West at least, is descended from an MRCA in historical times. They suggest, for example, that everyone in the West is descended from Charlemagne, c. 800 AD.

      It would seem possible that, even with a lot of geographical separation, the MRCA of the entire world is still within historical times, 3000 BC - 1000 AD. In fact, it is quite likely the entire world is descended from the Ancient Egyptian royal house, c. 1600 BC.

      We pick them as an example because they left proven descents for centuries, so it seems likely their descents did not die out, and they are ancestors of some people alive today. Hence probably ancestors of all people alive today.

      Quite likely almost everyone in the world descends from Confucius, c. 500 BC. We pick him as an example because he is the proven ancestor of some people alive today. Hence probably the ancestor of all people alive today.

      Atlantic Magazine, among others, had a story on this a few years back [theatlantic.com].

      The mathematical study of genealogy indicates that everyone in the world is descended from Nefertiti and Confucius, and everyone of European ancestry is descended from Muhammad and Charlemagne

  • Not me (Score:5, Interesting)

    by bsartist (550317) on Sunday July 02, 2006 @03:05PM (#15646614) Homepage
    I've never been able to trace back any further than 1650 or so. Not that I've tried all that hard - it's at that point where I have to leave the US and travel to England to find more, and that's way beyond my budget. My ancestor arrived in the US not only broke, but in debt - he had to pay for his passage with several years of indentured servitude. Not much has changed...
    • Re:Not me (Score:5, Funny)

      by MMC Monster (602931) on Sunday July 02, 2006 @05:43PM (#15647190)
      You only had one ancester in the 1600s?

      Maybe you had some others that you haven't found out about yet. :-)
  • futurama... (Score:2, Funny)

    by m1ndrape (971736)
    I'm my own grandfather...
  • Your mother was a hamster and your father smelled of elderberries!

    So, this could be true if we changed mother to 'great-great-great-great-great-great-great-great-g reat-great-grandmother' ?

  • Easy to forget (Score:5, Insightful)

    by quokkapox (847798) <quokkapox@gmail.com> on Sunday July 02, 2006 @03:13PM (#15646647)
    If you don't explicitly document your ancestry, you'll forget it. There are things my parents don't know which my remaining grandparent has long since forgotten. We have family pictures of people we don't know anymore.

    The fact is, we live in the present, and that's what is important. I couldn't care less if your great-great-grandmother was the queen of spain, or if your grandfather's second cousin's dad was a slave. That needn't have any effect on how I interact with you.

    • Re:Easy to forget (Score:5, Insightful)

      by rinkjustice (24156) <rinkjusticeNO@SPAMNO_SPAMrocketmail.com> on Sunday July 02, 2006 @04:14PM (#15646863) Homepage Journal
      Knowing your past helps understand who you are, and what you'll likely be up against in the future. If, by chance, you suffer from a particular disease or disorder, it's important to know what side of the family you inherited that genetic malady from, and how seriously it affected those ancestors. It helps you feel less weird and alone, and if your ancestors lived to a ripe old age, then that should give you hope for the future.

      It's also "a good thing"TM not to be forgotten forever in time. Your ancestors may have lived intersting lives and have interesting stories to tell. They were likey good people who don't deserve to be sloughed off into distant and lost memory.
  • by Anonymous Coward on Sunday July 02, 2006 @03:13PM (#15646648)
    here's the beginning, taken from:
    http://www.fictionwise.com/ebooks/eBook918.htm [fictionwise.com]

    With hindsight, I can date the beginning of my involvement in the Ancestor Wars precisely: Saturday, June 2, 2007. That was the night Lena dragged me along to the Children of Eve to be mitotyped. We'd been out to dinner, it was almost midnight, but the sequencing bureau was open 24 hours.

    "Don't you want to discover your place in the human family?" she asked, fixing her green eyes on me, smiling but earnest. "Don't you want to find out exactly where you belong on the Great Tree?"

    The honest answer would have been: What sane person could possibly care? We'd only known each other for five or six weeks, though; I wasn't yet comfortable enough with our relationship to be so blunt.

    "It's very late," I said cautiously. "And you know I have to work tomorrow." I was still fighting my way up through post-doctoral qualifications in physics, supporting myself by tutoring undergraduates and doing all the tedious menial tasks which tenured academics demanded of their slaves. Lena was a communications engineer--and at 25, the same age as I was, she'd had real paid jobs for almost four years.

    "You always have to work. Come on, Paul! It'll take fifteen minutes."

    Arguing the point would have taken twice as long. So I told myself that it could do no harm, and I followed her north through the gleaming city streets.

    It was a mild winter night; the rain had stopped, the air was still. The Children owned a sleek, imposing building in the heart of Sydney, prime real estate, an ostentatious display of the movement's wealth. ONE WORLD, ONE FAMILY proclaimed the luminous sign above the entrance. There were bureaus in over a hundred cities (although Eve took on various "culturally appropriate" names in different places, from Sakti in parts of India, to Ele'ele in Samoa) and I'd heard that the Children were working on street-corner vending-machine sequencers, to recruit members even more widely.

    In the foyer, a holographic bust of Mitochondrial Eve herself, mounted on a marble pedestal, gazed proudly over our heads. The artist had rendered our hypothetical ten-thousand-times-great grandmother as a strikingly beautiful woman. A subjective judgment, certainly--but her lean, symmetrical features, her radiant health, her purposeful stare, didn't really strike me as amenable to subtleties of interpretation. The esthetic buttons being pushed were labeled, unmistakably: warrior, queen, goddess. And I had to admit that I felt a certain bizarre, involuntary swelling of pride at the sight of her ... as if her regal bearing and fierce eyes somehow "ennobled" me and all her descendants ... as if the "character" of the entire species, our potential for virtue, somehow depended on having at least one ancestor who could have starred in a Leni Riefenstahl documentary.

    Well worth reading, along with the rest of the stories in the collection "Luminous" by Greg Egan. here's another link to some favourable reviews of his stuff: http://www-users.cs.york.ac.uk/susan/sf/books/e/eg an.htm [york.ac.uk]
  • by ems2 (976335) on Sunday July 02, 2006 @03:14PM (#15646650) Homepage
    It means when Muslims, Jews or Christians claim to be children of Abraham, they are all bound to be right.
    I know Jews [wikipedia.org] and some Muslims [wikipedia.org] claim to be children of Abraham but I never heard of a group of Christians claiming to be children of Abraham.
    • I never heard of a group of Christians claiming to be children of Abraham.

      There ARE hebrew and arabic Chirstians, you know.

      In a way, it's too bad that Mohammad wasn't around when Christ was walking the holy land. If the Prophet of Islam had met Christ, they would probably have formed one relgion instead of two.
      • In a way, it's too bad that Mohammad wasn't around when Christ was walking the holy land. If the Prophet of Islam had met Christ, they would probably have formed one relgion instead of two.

        Excuse me? The two religions are not compatible. The only way I can make your statement work is if the "Prophet of Islam" became a Christian.
    • by mypalmike (454265) on Sunday July 02, 2006 @03:22PM (#15646677) Homepage
      This is a song we sang at a Catholic church when I was a kid:

      Father Abraham had many sons
      And many sons had Father Abraham
      I am one of them
      And so are you
      So let's all praise the Lord.
      Right Arm, Left Arm... (There was some weird "hokey pokey"ish dance aspect to it.)
  • by 99luftballon (838486) on Sunday July 02, 2006 @03:14PM (#15646655)
    Given the worldwide geographical spread of Homo sapiens it's a believable number. As recently as 75,000 years ago we lost around two thirds of the population in the Lake Toba eruption and there have been a fair few fluctuations since then.

    The stuff later in the article is interesting. One question it raises is the effect of the increases in travel will have on the genetic mix. Traditionally the vast majority of the population married someone within a small radius of their initial home. As larger numbers of people move further away there could be some interesting effects.
    • by El Torico (732160) on Sunday July 02, 2006 @03:51PM (#15646796)
      500 BC vs. 73,000 BC? That's a very big difference, and I'm inclined to believe the latter number. The article gives ranges; one is a very wide range of 5000 BC to 1 AD. However, the article is too vague to find out what rates of migration were used and why they were used. It would be interesting to see if actual historical migrations were used. There are a lot of other variables that need to be taken into account.

      Also, how well does this match up with the "genetic drift model"? The numbers don't agree, so further refinement is necessary.

      Based on another article on this, http://www.sciencedaily.com/releases/2004/09/04093 0122428.htm [sciencedaily.com], it appears that the point isn't "All of us have one common ancestor in the collective sense, but that any two of us, regardless of distance, have a common ancestor who lived at about that time." That's just the way I interpret it.
      • by Mr. Underbridge (666784) on Sunday July 02, 2006 @05:28PM (#15647135)

        The problem is, they start with a set of mathematical assumptions and then do calculations and get this result. As with most purely computational studies that get outlandish results, I'm more likely to question the assumptions than believe the result. And I say this as someone who works with a lot of stats and probabality in my profession, and having made the same mistakes. The thing is, like all theorists, having made the prediction they need to find genetic evidence to back it up. Unfortunately, they're not going to find it.

        The studies I've seen that actually studied genetic evidence give a figure closer to 10s of thousands of years.. There's no way it's as short as the 2000 years they claim, just based on common sense - look at the different peoples in different regions - they most certainly *don't* share the same gene pool. Also, there are multiple versions of the Y chromosome floating around that don't converge that recently.

        The Genographic Project is currently estimating 60K years for the "Genographic Adam" from whom everyone on earth is dsecended, not 2K. I think you may be correct on the interpretation of "any two people are connected by some common ancestor 2000-5000 years ago," which is just a modification of the Kevin Bacon game. It's not the same as "everyone is descended from some common person 2000-5000 years ago - and from the interpretation in the /. article, that's definitely what they mean. And it's dead wrong.

  • by SpectreHiro (961765) on Sunday July 02, 2006 @03:22PM (#15646678) Homepage
    Despite the age of our species, every human on earth can trace their ancestry back to someone who may have lived as recently as the Golden Age of Greece (around 500 BC)

    Well damn, I can trace my ancestry to someone much more recent than that. To boot, I'm pretty sure we all have ancestors that lived during 500 BC... I dare you to find me someone who lacks a living ancestor during anytime past the origin of life on earth and before their own time. I frickin' dare you.

    Ohhhhhh... They mean to say that everyone can trace their ancestry back to a single person who lived during the Golden Age of Greece. That guy must've been a stud.
  • Impressive (Score:2, Funny)

    by DuckWizard (744428)
    Despite the age of our species, every human on earth can trace their ancestry back to someone who may have lived as recently as the Golden Age of Greece (around 500 BC)

    This fellow must have been quite busy with the ladies.

  • by reporter (666905) on Sunday July 02, 2006 @03:27PM (#15646697) Homepage
    That the human population is descended from a tiny group of people has another, more deadly, implication [newscientist.com], according to "New Scientist". The relative inbreeding increased our susceptibility to genetic disease.

    The "New York Times" gives a detailed analysis of genetic disease in Saudia Arabia [middleeastinfo.org], where more than 50% of marriages are ones between blood relatives.

    Curiously, the nature of genetic disease suggests that if you want to ensure the survival of your descendants into the eons upon eons, you should marry outside of your ethnic group. The offspring of an Eskimo-African couple will typically have a stronger set of genes than the offspring of an Eskimo-Eskimo couple, a German-German couple, or a Vietnamese-Vietnamese couple.

    • by Anonymous Coward
      Curiously, the nature of genetic disease suggests that if you want to ensure the survival of your descendants into the eons upon eons, you should marry outside of your ethnic group. The offspring of an Eskimo-African couple will typically have a stronger set of genes than the offspring of an Eskimo-Eskimo couple, a German-German couple, or a Vietnamese-Vietnamese couple.

      That is patently false. Humans, before we had modern technology that allowed us to travel great distances in short periods of time, had ver
      • by Grym (725290) on Sunday July 02, 2006 @06:30PM (#15647352)

        Humans, before we had modern technology that allowed us to travel great distances in short periods of time, had very little contact outside of our own tribes. To put, humans lived within their own tribes for hundreds of thousands of years.

        I've just completed a bachelor's degree in Biology and a graduate level course in evolutionary genetics and I have never heard of these kinds of statements from any scientific source. In fact, the only place I have heard them from were from people who stress racial purity and--more specifically--white supremacy.

        Regardless, what you're saying is ridiculous. Humans are the most prolific mammal on the face of the earth; we're everywhere. We are this way because it is our nature to be both curious and aggressive. You're not giving our ancestors or the human drive for exploration enough credit. Besides, even under your theory, how did the individual ethnic groups arrive in their respective regions were it not for this migration, mmm? (Hint for the uninitiated: the typical answer to this is "God put them there.")

        For any human population a certain number of migrants is a given. This inevitably creates geneflow between populations which are otherwise isolated. The result is that human populations are generally homogenous, despite the great geographic distances separating the groups themselves. A very extreme example of this effect is demonstrated with ring species [wikipedia.org], whose sub-populations are actually infertile with one another (clearly not the case with people) but still maintain a common character (ie. they do not diverge) because of geneflow.

        To be certain, there are differences between racial and ethnic groups, but these differences are superficial and do not reflect the genome as a whole. Scientific studies of DNA microsattelites have confirmed this time and time again. In fact, the study in the article is just one of many.

        . Why do you think the traits of various ethnic groups were selected? Do you think they are randomly arranged? No, they were selected based on adaptations to the environment of that group of people. Mixing in differnet traits that do not fit well into that environment will result in those traits being removed.

        Yes and no. What you're talking about is a homozygous advantage. For many populations this is true--but not for people. Why? Because we aren't necessarily beholden to our environments anymore. If you're less tolerant of the sun, you can wear sunscreen. If you're less tolerant to the heat, you can get air conditioning. Even in the most extreme cases, homozygous advantage doesn't apply. For instance, populations that have lived in the Andes mountains have developed genetic adaptations that allow them to breathe in much lower concentrations of oxygen than normally allowed. And yet, still, most tourists to these mountains are still able to survive (and even enjoy themselves) by supplementing their oxygen.

        But if no the environment, what are humans subject to? Their own genes. To some extent this can be compensated for. (I know I for one would probably have died in ages past because of my nearsightedness.) But even with today's technology, genetic defects are often untreatable and sometimes fatal. This is particularly relevant in the case of recessive genetic disorders, where the extreme effects of a homozygous recessive trait can be masked. This creates a situation where heterozygotes are superior, because of a reduced likelihood of genetic disorders. I'm pretty sure this is the scientific basis of the OP's more-simplified statements.

        In practice, however, this is often difficult to take advantage of because our assignment of race is completely arbitrary and based upon the phenotype of an individual and not his or her genotype. So, for instance, a black and white couple in Claxton, Georgia (a historic site of genetic samplin


    • The offspring of an Eskimo-African couple will typically have a stronger set of genes than the offspring of an Eskimo-Eskimo couple, a German-German couple, or a Vietnamese-Vietnamese couple.


      This makes no sense.

      The offsprings of to compleatly healthy parents can only get a genetic defect by external influences, like virus infections during pregnancy, posions(chemicals) or radiation etc.

      If the parents have 100% perfect genes, the children will have as well. No matter how close the parents are related.

      Your ab
  • weak argument (Score:3, Insightful)

    by Khashishi (775369) on Sunday July 02, 2006 @03:40PM (#15646751) Journal
    The article isn't all that convincing. Just because the number of humans was small and the number of ancestor branches is large isn't enough to say that one's ancestors make up all the humans.

    Essentially, the article is implying that people in all geographical areas have been in interbreeding contact with peoples of all other geographical areas--within the last 5000 years!

    It seems like some kind of feel-good rhetoric (we are all one people). Prove it.

  • by mrmeval (662166) <mrmeval&gmail,com> on Sunday July 02, 2006 @03:49PM (#15646787) Journal
    WE'RE ALL REDNECKS!
  • by jaymzter (452402) on Sunday July 02, 2006 @03:49PM (#15646788) Homepage
    But if you're one of the races that may have been dislocated due to the depradations of colonialism or slavery, you're pretty much denied any chance of a family tree dating back to the "Golden Age of Greece".
    Yes, it comes off as a troll or flamebait, but that's not the intent. It's just a sad fact of history that there's a lot of people disconnected from their past due to the way the world operated at a particular point. So flame away, but I'd rather hear any ideas that could work around the problem.
  • by claes (25551) on Sunday July 02, 2006 @04:14PM (#15646866)
    Richard Dawkins writes in The Ancestors Tale (page 43, "The Tasmanian's Tale") that roughly 80 percent of all invidiviuals of a current population will be universal ancestors to all living decendants a certain number of generations later. How many generations? That depends on the populations size: roughly the base 2 logarithm of the population size number of generations. This is more true for small, isolated populations, especially on islands (Tasmania is given as example) - you can not take the current population of people on earth today (6 billions) and trust this number.
  • by RealGrouchy (943109) on Sunday July 02, 2006 @04:40PM (#15646954)
    A way to visualize what he is saying would be to take two overlapping cones/triangles, one with the point aiming up, one with the point aiming down, like a star-of-david, or an angular hourglass.

    The cone with the point at the top represents one person (A, for ancestor) who lived X years ago and their descendants. The cone with the point at the bottom represents one person (D for descendant) who lives today and their ancestors. Any overlap is where A and D share mutual ancestors/descendants.

    Using this representation, the argument here is that there exists (erm, existed) a person A, for whom every human who is alive today falls into their descendancy cone. Or more importantly, they assert that this is inevitable, and sufficient time has passed such that it has already happened. The key, according to this visual model, is that "now" is below the line where the two cones cross.

    - RG>
  • by cfulmer (3166) on Sunday July 02, 2006 @05:51PM (#15647214) Homepage Journal
    Take a native american in the 1700s. Is he descended from some greek guy 3000 years earlier? I have my doubts -- if I recall my anthropology, the natives came here long before Greece was a major power. If there are any purebred native americans around today, then you'd have to go back a lot more than 3000 years to find an ancestor that he has in common with, say, a bushman in Africa.

    • It only takes one European crossing the ocean to make Americans start popping out babies with European heritage. Let simmer a few generations and the whole idea becomes plausible.

      Note that it could just as easily have been a lone American crossing to Europe.
  • Faulty Logic (Score:5, Interesting)

    by cylence (129937) <micah@cowan.name> on Sunday July 02, 2006 @09:03PM (#15647703) Homepage

    The math only works if you assume that the ancestry never coincides with itself until it is mathematically impossible for it not to do so. This is ludicrous. Ancestry will coincide many, many times before that point. It is easy to demonstrate mathematically that it is more than possible for an ancestry to fold in on itself repeatedly, without touching other distinct lines.

    The basic assumption (flawed), is that having trillions of "ancestors" means that it fold in across the entire spectrum of living people at a given time, when it can in fact fold in multiple times on a selection of that population; or that having any particular person as your ancestor is almost precisely as likely as any other arbitrary person. Historically, there are many social constrictions to make such statistics highly unlikely.

    It also seems obvious to me, that were interracial marriages so common place so long ago (across the last few thousand years, even), the world would not be quite as genetically diverse a place as it currently is.

    Disclaimer: IANAM(athematician). However, I do love math, and this seems like a fairly obvious and very easily provable flaw. I'm also probably misusing the phrase "fold in" above, though: but I imagine everyone can understand what I mean by that.

  • by ShakaUVM (157947) on Monday July 03, 2006 @01:11AM (#15648362) Homepage Journal
    Authors don't understand the pigeonhole principle:

    (From the FA): "Keep going back in time, and there are fewer and fewer people available to put on more and more branches of the 6.5 billion family trees of people living today. It is mathematically inevitable that at some point, there will be a person who appears at least once on everybody's tree."

    No, not at all. You could have, for example, two completely separate branches of humanity (say one in the Americas and one everywhere else) that never interbred except at the very beginning of the human species. Pigeonhole Principle. The only thing thats mathematically inevitable is that at least two ancestors somewhere is shared. Somewhere. For example, mathematically, a very prolific couple could have been responsible for all X billion people minus a small group living in an uncharted area, whose roots go all the way back to the beginning.

    Bad math, shame on the authors for writing it.

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