The Shallow Roots of the Human Family Tree

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."

Comments

Family Tree Grafting

[ObsessiveMathsFreak]

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?

Re:Family Tree Grafting

[Peyna]

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.

Re:Family Tree Grafting

[netsharc]

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..

Re:Family Tree Grafting

[gEvil (beta)]

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?

Re:Family Tree Grafting

[forkazoo]

But while we're on the subject, I do wonder why a woman asserting her independence by refusing to take her husband's name when getting married feels perfectly comfortable carrying her father's name. According to the Wikipedia article, the practice is generally in decline, but for those of us old enough to remember the shrill "I'm no one's property" arguments before the notion became politically correct and commonplace, the irony lingers. Even funnier if you've been through divorce court.

I have always expected that there would be a movement where a man and woman get married and pick a new family name. It just seemed logical to me. Neither party has to take the other's name, and they also get to share a common family name which would symbolise the bond. Hasn't happened yet, but I still figure it might. Especially if gay marriage takes off. Then, how do you decide who's name to take? Flip a coin?

Re:Family Tree Grafting

[radtea]

The test is probably real, it's just that there isn't really set "race genes."

That's because "race" is far more of a social phenomenon than a biological phenomenon, and the obsession with defining or determining which race a person belongs to is something that does not stem from anything other than politics and sociology. It is a question that no biologist would ever think to ask, because race is not a useful or interesting biological category. There are two reasons for this.

The first is that few if any racial characteristics show any significant discontinuity in the population at large--the lightest-skinned "black" person is lighter than the darkest-skinned "white" person. Without such discontinuities the idea of race becomes entirely arbitrary, based on a line drawn for purely political purposes.

The second is that insofar as there are relatively-disconnected pools of genes in the human population, they are small and don't last very long because of our aggressive pursuit of exogamy (breeding outside our kin-group). Most primate species practice inbreeding more than outbreeding. In humans it is rather the opposite. In simple terms, most of us are of mixed race. This is especially true of North Americans with regard to mixing of blacks and whites, for well-known reasons.

Anyone who believes that "racial purity" is either possible or desirable is merely proclaiming their ignorance of human biology.

Re:Family Tree Grafting

[Anonymous Coward]

If you go x generations back, there are 2^x "ancestors" (1 generation before you: 2^1 = 2 parents, etc).

Not down South.

Re:Family Tree Grafting

[elronxenu]

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.

Re:Family Tree Grafting

[Cyryathorn]

"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).

Re:Family Tree Grafting

[jc42]

There's an easy solution. Assume that Mrs. Smith marries Mr. Jones. They take the family name Jones-Smith. Their daughters, upon marrying, drop "Jones" (the father's name). Their sons, upon marrying, drop "Smith" (the mother's name). So if Ms. Jones-Smith marries Mr. Jefferson-Clark, they couple takes the name Jefferson-Smith. A person would then share a name with their father, grandfather, great-grandfather, etc, as well as their mother, grandmother, great-grandmother, etc.

You've described the essence of the traditional naming scheme in Iberia (Spain, Portugal). There's inconsistency about whether the paternal name comes first or last. The upper classes often preserve more than just two names, and sometimes tack on "de" and a place name. Most people just use two family names, though, which probably saves them a lot of writing over a lifetime.

Of course, in most of Europe, family names often only go back a century or two, before which people had just a given name that could be augmented by a profession or place of origin or a descriptive term. Or just "'s son", which is often specific enough in a typical village. In Iceland, they still don't use family names, just patronymics.

I know a number of people from Scandinavia who have a specific last name because their parents or grandparents bought a farm, and they adopted the farm's name (whose origin is often lost to history).

A similar thing was done by the UK's royal family. They adopted the family name Windsor in 1917 to dissociate themselves from their German ancestors. They were at war with Germany, and wanted to sound English. Windsor was, of course, the name of one of their castles. A quick google for "Windsor royal family name" gets nearly 3 million hits, so you can easily read lots of takes on this particular family name.

My favorite name from my family tree is Cameron, which is a simplified spelling of a Scots Gaelic phrase meaning "broken nose". It seems there was this particularly belligerent fellow who was a clan leader, and a lot of his relatives decided to adopt that insult as their name, as a way of thumbing their noses at the taunters.

Re:Family Tree Grafting

[The Nordic Beast]

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.

Re:Family Tree Grafting

[jc42]

I have always expected that there would be a movement where a man and woman get married and pick a new family name.

I know a number of couples who have done this. Actually, in each case they combined their original names in some clever way to make a combinatin that they liked.

I've heard a number of lawyers explain that in all US states except Louisianna, the laws about names go back to English Common Law, where the rule was that you can use any name you like, as long as it isn't fraudulent. You can't pick a famous name and pretend to be that person, and you can't change your name to escape debts or prosecution. But if your name change (as in a marriage) is published in the official records, that constitutes public notice and you can't be charged with fraud after the change is officially published. They usually say this to explain why there's no legal problem with a woman keeping her original name after marriage. But I've also heard this used to explain why a couple that makes up a new family name and writes it on their marriage registration is fully within their rights, regardless of what ideas others may have on such things. And, historically speaking, neither practice is especially new or unusual in the English-speaking parts of the world.

Funny story: One such couple is two women who recently married here in Massachusetts, where it has been legal for a few years (and so far it hasn't destroyed any mixed-sex marriages that anyone knows of, even if a lot of men think they're both very attractive women ;-). They recently renewed their passports, and sent in requests for a name change to their new combined last name. One was accepted (because they are legally married), one was rejected (because US federal law doesn't recognize same-sex marriage). Two different bureaucrats, two different decisions in exactly the same case.

Of course, having a different name on your passport and other ids isn't at all unusual. Newly-married women routinely find themselves in this situation, and it doesn't seriously interfere with travelling. This couple mostly think it's funny. "Guess what those idiots in the passport office just did."

What I'm looking forward to is the fun of watching US law adapt to the slowly-growing Muslim population. I can see a couple going off to Morrocco or Indonesia on vacation and coming home with a new wife in the family. I wouldn't be surprised if this has happened already, but they kept it quiet and didn't try to get official papers changed. But it's just a matter of time, and it'll be fun to follow the outrage and consternation from the bigot crowd, while the lawyers calmly ask what laws have been broken ...

Re:Family Tree Grafting

[plunge]

Um, what the heck are you talking about? I'm not an expert in transplantation, but I'm familiar enough to know that what you're saying sounds like complete BS: a person's race is neither predictive nor particularly significant compared to all the other important factors. You're talking as if race were more important than blood type, which is pure crazytalk. I don't know what doctors told you this, but it sounds more like you heard what you wanted to hear.

Differences in race are both fairly minor AND have more variance than they do absolute differences. Lactose tolerance is a particularly goofy example, because it's both such a minor difference AND still not as universal as you make it out. Not all Asians are lactose intolerant, and not all people from Wales aren't. There is no medical feature that's both universal to and unique to any "racial" group.

I knew that racism was still a major cultural problem in China, but this takes the cake.

Re:Family Tree Grafting

[Richard Kirk]

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.

Not me

[bsartist]

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

[MMC Monster]

You only had one ancester in the 1600s?

Maybe you had some others that you haven't found out about yet. :-)

What native Tasmanian population?

[tetromino]

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.

Easy to forget

[quokkapox]

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

[rinkjustice]

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.

Greg Egan wrote a good short story on this in 1995

[Anonymous Coward]

here's the beginning, taken from:
http://www.fictionwise.com/ebooks/eBook918.htm

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

Christians claim to be children of Abraham?

[ems2]

It means when Muslims, Jews or Christians claim to be children of Abraham, they are all bound to be right.

I know Jews and some Muslims claim to be children of Abraham but I never heard of a group of Christians claiming to be children of Abraham.

Re:Christians claim to be children of Abraham?

[mypalmike]

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.)

Re:Christians claim to be children of Abraham?

[Triv]

(There was some weird "hokey pokey"ish dance aspect to it.)

He lets the righteous in,
He kicks the heathens out,
He lets the righteous in, and he plops 'em on a cloud
We do the hokey-pokey to prove we're all devout,
That's what God's all about.

--Triv

Re:Christians claim to be children of Abraham?

[Khomar]

Never fear. Had the Prophet met Christ, there would only be one of those religions around today -- that whose leader wasn't killed in the ensuing war.

I found your comment somewhat comical considering that Jesus did die. Not from a war, but because he allowed the leaders of his day capture and crucify him. He then rose from the dead which marked the beginning of Christianity. Given his teaching, the Christians would not have been the ones fighting the war.

If the proposed situation did occur, the muslims would have probably attacked the Christians (just as the Romans did), but the Christian church has always grown the fastest when it has been under the greatest persecution. Net result: the large Christian church you see today. Just because one side can kill better than the other does not mean that the more peaceful side will not win in the end.*

* Admittedly, many people have used the name of Christ to justify their wars (just as people always some kind of justification for what they want to do that is wrong), but I think you would find that very rarely was it truly done in the name of Christ and in keeping with His teachings.

Re:Christians claim to be children of Abraham?

[LordLucless]

Christianity became a successful religion only because of its follower's willingness to use violence to capture, torture and kill their opponents. By infiltrating the halls of power and gaining influence over the secular means of repression they were able to extend their reach even further.

You have it around the wrong way. Christianity in general spread first to a region, then ambitious political men rode it to try and achieve their own agendas. Trying to force religion on a population against their will is an act of futility. Most of the violence you're talking about (the notable incidents are the various crusades and the Spanish inquisition) were fueled by politics, with a Christian sugar-coating to stop people complaining about them.

Also, assuming the current records of Jesus' words are reasonably accurate (and if you have any that are more accurate I'd like to know) it's certain that he did not see himself as a prophet to the Jewish people. In Matthew, for instance, in what is known as the Great Commission, Jesus tells his disciples "therefore go and make disciples of all nations". His dealings with other people (say, the Samaritan woman at the well) also make it clear that his message is not exlusively for Jews, although his personal ministry was generally in Israel, and hence, he had a largely Jewish audience.

Re:Christians claim to be children of Abraham?

[Triv]

oh. my. god. Or rather, apparently, yours.

It was a joke. It was funny. I dare you to find a situation where god leading a spectacular, heavenly rendition of the Hokey Pokey ISN'T funny.

Chill, dude. Seriously. You're gonna give yourself an aneurism if you're not careful.

Triv

Re:Eww yuck!

[kimvette]

No it wouldn't. Despite the wealth of information available today, racists will consider people with different color skin or slightly differently shaped eyes to be less than human. There is no rationale behind it whatsoever and having a pedigree to show that say, (for the most common example) a white supremacist and Martin Luther King Jr. share common ancestors 60 or so generations back would not change their attitudes.

Re:Eww yuck!

[bsartist]

Or am I related to Kevin Bacon?

Well I'll be damned - that game really does work. Five steps from me to Kevin Bacon:

1. My niece is Angel Boris
2. ... who appeared in Dragon Storm with John Rhys-Davies
3. ... who appeared in The Great White Hype with Samuel L. Jackson
4. ... who appeared in Sphere with Dustin Hoffman
5. ... who appeared in Sleepers with Kevin Bacon.

Re:Eww yuck!

[bsartist]

There is no rationale behind it whatsoever and having a pedigree to show that say, (for the most common example) a white supremacist and Martin Luther King Jr. share common ancestors 60 or so generations back would not change their attitudes.

You're right, it wouldn't change any attitudes. But it would get you a beating from a bunch of pissed-off skinheads.

So our family tree has no forks?

[mrmeval]

WE'RE ALL REDNECKS!

Re:The start of a long road

[El Torico]

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, 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.

You can be a universal ancestor too!

[claes]

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.

Indeed, Jewishness

[Flying pig]

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.)

Re:Indeed, Jewishness

[the phantom]

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.

Re:Indeed, Jewishness

[XchristX]

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

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

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

  As well as the reigning queen of Jhansi, Laxmibai

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

  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

  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

  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.

Another way of putting it...

[RealGrouchy]

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>

Re:The start of a long road

[Mr. Underbridge]

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.

Re:From TFA

[TubeSteak]

If you knew anything about Iraq & Iran, you'd know that Iraq is an Arab country and Iran is a Persian country.

The Arabs have a long running grudge against the Persian empire, which Saddam used to unite the Iraqi people during that war.

Maybe 30% of Iraqi families are mixed Sunni-Shia. To pretend that the sectarian violence in Iraq isn't religiously motivated is ignorance in the extreme.

It's exactly the thing that Bush Sr. predicted would happen if he invaded Iraq. So he didn't. If you honestly believe that "This generally artificial tension is being produced as a convenient cover" then i suggest you go read a book or two, because Civil War is exactly what most political scientists expected would happen.

Re:Eww yuck!

[radtea]

There is no rationale behind it whatsoever and having a pedigree to show that say, (for the most common example) a white supremacist and Martin Luther King Jr. share common ancestors 60 or so generations back would not change their attitudes.

I agree it won't change their attitude, but given the deplorable fact of extensive inter-breeding between mostly black slaves and mostly-white plantation owners prior to the Civil War, it is extremely likely that a white supremacist in the U.S. South and Martin Luther King Jr. would share a common ancestor a lot less than 60 generations back.

The idea of "racial purity" is a myth for stupid people, and as more knowledge of human genetics and human ancestry accumulates this will become so obvious that even people stupid enough to be racists will have a hard time avoiding it. We will find there is a literal handful of "racially pure" people on the planet, and they will be from isolated tribes who simply lacked the opportunity to practice the vigorous out-breeding that is part of humanity's evolutionary modus operandi.

Re:Additional Startling Implication: Genetic Disea

[Grym]

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, 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

Re:Somewhat misleading

[Hepneck]

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.

Faulty Logic

[cylence]

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.

Re:Persian country?

[TubeSteak]

Iran isn't a Persian Country.

Persia was the name used outside of Iran up until 1935.
Iranians called their land Iran beginning around 226 AD/CE
Yes, I wrote that correctly. 1,780 years of calling themselves Iranians.

Before 226 AD, the Persians referred to themselves as Aryanam, which the word "Iran" is a spinoff of. The earliest written self-reference of the Persians as Aryanam was in 486 BC. That stretches the Iranian timeline back another 712 years.

Iranians are Caucasians

Iran (the Persian Empire) started out roughly 700 BC when several Aryan tribes united.
Iran literally means "the land of Aryans"
Culturally and linguistically they're Aryans.
Ethnically, Iran (the Persian Empire) is a mix, which includes Caucusians.

It's a bit confusing to discuss since the 'Iranian (Persian) people' covers more than just the people inside Iran's current border.

P.S. Aryan, as I'm using it, has nothing to do with the racial supremecists or Nazis. In the 1900's they confused & bastardized the word.