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Family trees: Tracing the world's ancestor (bbc.co.uk)
162 points by selvan on Aug 22, 2012 | hide | past | web | favorite | 137 comments

The Ancestor's Tale by Richard Dawkins looks at our ancestry right back to the start of life:


It looks at a list of different species and then considers the most recent common ancestor we have with that species - fascinating stuff.

"Happenings are sometimes organised at which thousands of people hold hands and form a human chain, say from coast to coast of the United States, in aid of some cause or charity. Let us imagine setting one up along the equator, across the width of our home continent of Africa. It is a special kind of chain, involving parents and children, and we will have to play tricks with time in order to imagine it. You stand on the shore of the Indian Ocean in southern Somalia, facing north, and in your left hand you hold the right hand of your mother. In turn she holds the hand of her mother, your grandmother. Your grandmother holds her mother's hand, and so on. The chain wends its way up the beach, into the arid scrubland and westwards on towards the Kenya border.

How far do we have to go until we reach our common ancestor with the chimpanzees? It is a surprisingly short way. Allowing one yard per person, we arrive at the ancestor we share with chimpanzees in under 300 miles. We have hardly started to cross the continent; we are still not half way to the Great Rift Valley. The ancestor is standing well to the east of Mount Kenya, and holding in her hand an entire chain of her lineal descendants, culminating in you standing on the Somali beach." http://tabish.freeshell.org/animals/human-chain.html

Someone has decided to downvote you. I really don't much like Dawkins (I'm a Christian), but this is very interesting. I hit the update button - your comment is a very worthy contribution to this discussion!

I suppose I understand, but his science books (which all of them are, save for "God Delusion") are top notch. If you want to understand Evolution, there's no better writer on the topic.

I would consider The God Delusion a science book.

(It's really good btw. I would recommend it to any theist.)

Even when I was a Christian I was a fan of Dawkins. If you read his books/watch his talks/debates he always comes across as very reasonable and polite. Way more so than you might have been lead to understand. The worse he has ever gotten was with the name of that documentary, "Root of all Evil", though he didn't pick the name and in fact disliked it, noting that it was a bad title because it wasn't true (religion is not the root of all evil).

Also Christian here. I loved reading a few Dawkins books. Then I learned about his stance on religions... Well, I prefer if we just stick to science.

Serious question: Did your learning about Dawkin's views on religion change your opinion of him as a scientist?

It didn't change my opinion of his science. It tore my feelings towards the person conducting it.

At the risk of downvotes, religion used as anything other than philosophy is bad science. Even if there was/is a creator, it can't be "magic". Science doesn't allow for magic.

> Science doesn't allow for magic

No downvote here, but science "allows for" [sic] whatever IS. It's a bit above our pay grade to say what can't be; for all we know, magic might be a black swan [1].

[1] http://en.wikipedia.org/wiki/Black_swan_theory

Actually, science does not allow for magic. Either something has an explicable mechanism by which it works, and that mechanism can be exposed through the scientific method, or it's supernatural. The supernatural is, by definition, inexplicable through science.

A black swan event is merely the occurrence of a highly improbable event. That says nothing of the event's explicability.

Edit: more accurate to say science cannot explain true magic, if there were such a thing.

Science does in fact allow for magic. If it were true that saying several syllables in succession accompanied by appropriate gestures caused lightning to shoot from your fingertips in a repeatable manner, science could measure and classify it.

We do not know, as of yet, what, nor how many things are fundamental to the universe.

And thus, by explaining, measuring and classifying, lighting incantations are no longer magic.

If magic with an explicit lack of even the potential to be explained existed, science would still allow for it. At no point does science require that reality must explain itself.

Something seems wrong with this argument... Surely science is a subset of reality?

Any sufficiently advanced technology is indistinguishable from magic. - Clark

What's the difference between many religious concepts of gods and an extraterrestrial civilization that (at least on our scale) appears immortal, omniscient and all powerful?

Asimov's The Last Question illustrates the point pretty well:


What's the difference between many religious concepts of gods and an extraterrestrial civilization that (at least on our scale) appears immortal, omniscient and all powerful?

Two major differences:

1. Evidence. Extraterrestrial life is definable and testable. "God" by most definitions is unknowable, and most religious definitions of "god" and his/her/their/its work are contradictory to scientific evidence.

2. Purpose. Nobody has committed genocide in the name of extraterrestrial aliens, but religion has been used to justify all manner of atrocities.

Goodness, that's some fairly shoddy logic for point two! I could equally phrase this as "No religious group have committed genocide in the name of extraterrestrial aliens, but atheists have been known to justify genocide".

In other words, the first assertion includes everyone, including ALL religious people, and the second premise doesn't follow from the first anyway. Furthermore, the argument doesn't even answer the question between the differences between aliens and deity, because you are focussing on the religious movements and not the omniscient god!

All around, a poor effort.

I have the same gut reaction when I learn someone is religious/atheist. However, I after talking with most people what they say openly about religion vs what they say in private is often vary different. One of the most fascinating questions I think is 'how likely to do you think there is a universal creator?' Not based on what people say, but because it cuts though so much BS that people project.

Do you mean atheist as in, not agnostic? Because the two are not the same; Dawkins, for example, is an agnostic atheist, since he doesn't claim to know for sure.

Yup, IIRC, in the God Delusion, Dawkins talks about a belief spectrum. The spectrum ranges from 1 thru 7 where 1 is a strong theist who believes and knows there is a God and 7 is a strong Atheist who knows there is no God. Dawkins mentions he is a 6 (low probability of a God, doesn't know for sure but chooses to live on the assumption that there is no God) and leaning toward 7.

It's interesting that the discussion is in terms of God exists/doesn't exist. I think that already includes a pretty significant context. It's worth also considering the relevancy of the belief; the degree to which one's beliefs operate within that context. For example, that there is (or maybe there isn't) a guy on some planet somewhere named Booglifoog -- it makes no difference to me -- the question is irrelevant.

It's like skiing in the trees; if you want to succeed at this, focus on the spaces between the trees, not on the trees. Dawkins, for whatever reason, is distinctly focused on the trees.

I had a similar thought when I read about Dawkin's axis (which I didn't know about). It implies either an active embrace or rejection of god - particularly of the abrahamic god - that doesn't make sense to me, as someone who was born in a very non-religious setting.

As an Atheist I'm glad your feelings only matter to you, while science will outlast both of us.

The Ancestor's Tale by Richard Dawkins is a great book. Interestingly, he makes a point that because genes are shuffled, it is possible for the descendants from a common ancestor not to have a single gene from him.

This article makes the mathematical point, but deliberately ignores social reality. Yes, 100 generations is sufficient time for the premise to be possible, to fully propagate genes from every ancestor to every descendant.

But reality doesn't work that way. Human population groups breed within themselves. Mating pairs are not chosen at random from the entire human population. Consider all the remote groups that would have to be covered to satisfy the assertion. Someone alive today would have to become a common ancestor of every Lapp in Finland, every Aborigine in Australia, every Inuit in Nunavut, every Maori of Polynesia, every Falklander, every North Korean, and countless more groups that barely have any contact with the world community, let alone interbreeding. (And maybe we'll actually launch a Mars colony or interstellar generation ship, literally making it impossible.)

The article does mention this very offhandedly, inserting the clause "If people in this population meet and breed at random". But that antecedent is plainly false so the conclusions are not defensible.

I doubt this is as big a problem as you think. If you have any interbreeding at all the general conclusion holds. I would guess that even extremly low estimates of interbreeding rates wouldn't change the result much.

Note that the article never specifically talks about propagating genes, just about being an ancestor. No matter how many generations you go back, there will be at most 46 ancestors in that generation whose genes a descendant has, and only one ancestor's mitochondrial DNA.

Not true regarding 46 ancestors - chromosomal DNA is swapped between the homologous chromosomes during meiosis: http://en.wikipedia.org/wiki/Meiosis#Prophase_I

You are correct about mitochondrial DNA.

By the same mathematical logic, almost everyone in the US today is a descendant of European royalty -- even people who are predominantly African or Native American. Similarly, everyone in the US with primarily European ancestry is a descendant of both Muhammad, the founder of Islam, and Charlemagne, the so-called "Father of Europe."

These claims were made by an entertaining article written 10 years ago in The Atlantic, "The Royal We," which covered the mathematical study of genealogy and is a good companion to the BBC piece: http://www.theatlantic.com/magazine/archive/2002/05/the-roya...

Nice line from that article:

"Just as we are descended from most of the people alive on the planet a few thousand years ago, several thousand years hence each of us will be an ancestor of the entire human race—or of no one at all."

I've actually traced my ancestry back to Charlemagne. It's an interesting exercise. Some of my links are not very well substantiated, but the dozen or two generations from Charlemagne forward are fairly well documented, depending on how many of your ancestors were bastard children of some horny nobleman. (Of course there are countless poor peasant farmers between now and then as well.)

I've also traced my ancestry back to Charlemagne. It's good fun but it's not the iffy documentation that is the main problem. It's the milkman effect. In talking with a researcher at a genetic genealogy center he said that around 10% of the population has a different biological father than they think they do.

I'd love to see this either substantiated or debunked - I've seen this claim made and refuted many times, but have never found a truly reliable source.

My recollection is that this number is based on a percentage of individuals seeking paternity tests-- where obviously we would expect to see a much larger number of false paternities showing up than in the general population.

Hi cousin! I've heard this too, but I thought it was a lower percentage. Are there any good (DNA-based?) studies to support it?

I always get confused here between "Eve" and MRCA.

AFAIK "Eve" is not what we are talking here - that is not as identifying one person who is the ancestor of all living people, but that if we go back to the time of David, then he, and 80% of everyone alive at the time (approx 1 million) MUST be ancestors of everyone alive now. That is some of his DNA and some of everyone elses DNA at the time is in me.

That is pretty weird.

The other thing that gets me is that till agriculture, it seems human population was stable at around 1 million. Then it started to grow to 1 billion by 1800. Freddie Mercury could sing to the whole population of earth in three concerts.

I don't think the difference you're talking about is real. "Eve" is mitochondrial Eve, the most recent direct female-line ancestor-- the first human every woman can say was her mother's mother's mother's et cetera. There's a corresponding Y-chromosomal Adam; they probably lived 100-200,000 years ago, but not at the same time.

But of course if you're descended from her, you're descended from her parents, and her mate's parents too; nobody came from just one person. Each one out of our millions of common ancestors is an Adam or Eve by the popular definition: Every human being alive is descended from them. If they had not conceived, no one currently alive would exist. There was never a biblically singular Adam and Eve.

So, the first person who was the MRCA-with female lineage only, ie the earliest woman who was the female ancestor of all living people, was 100,000 years ago.

But the earliest ancestor (female / male / mixed lineage) was only 3000 years ago.

(i.e. the first, had to have daughters only, the second, more recent could have daughter then grandson then great-grandson etc)

So, 3000 years before we can say anyone definitely was the ancestor of all, and there would be a lot of them. And 100,000 years before its female lineage. Then pretty much everyone is a common ancestor, back to plankton. And Dinosaurs!

More or less, except 3000 years ago travel was far more of an issue. But, somewhere in the ~2,500-30,000 years it's probably true.

Also, with a population of 1 million people a female line 'wining' is much more likely than with a ~6 billion people population that probably will not happen again for a vary long time without some awesome mutation.

> the first human every woman can say was her...

I think that's a typo, should be: "...first woman every human...". All of us have Mitochondrial Eve as our matrilineal MRCA, not just those with two X chromosomes.

Yeah, good catch. I was hoping no one would notice that goof :)

Yes this is the key - people won't have just one ancestor but many millions.

> More specifically, imagine the simplest case of a population of a constant size - say a million (the approximate size of the Holy Land at the time of Jesus).

The total human population was greater than 1 million.

You're referring to the year 0 CE, he's referring to the advent of agriculture around 10000 BCE.

Mathematical proof why people get addicted to genealogy. They are almost certain to find they are related to someone famous if they go back far enough. It makes perfect sense why companies that provide genealogy research have no problem finding customers. The lure of finding out that you are as awesome as you thought you should be by way of royal bloodline, etc. is a pretty powerful market force.

My wife was playing around with the LDS Church's online genealogy tool and, not surprisingly, found European royalty in her ancestry. I don't think I quite succeeded at explaining that pretty much everybody would have those.

For me, far more interesting than who is in there is the path things took between me and that royalty.

The point in the title is valid, but his answer to the original question seems misguided to me: in the time of the bible the only lineage that mattered is the paternal one. If your grandmother was King David's daughter that would not make you his descendant. Not in the eyes of your contemporaries.

Except that Judaism has a form of Matrilineality so King David/etc were probably bad examples.

Matrilineality is mostly from the Talmud , a collection of Rabbinic opinion.

The Old Testament / Bible allows both parents to determine Judaism in the child.



I don't think so.

People will stop having offsprings (and even sex) well before that because they are immortal, even if they die, they can be resurrected because they have copies. Provided, human race doesn't get destroyed by itself or AI.

If you guys have not read Galapagos by Kurt Vonnegut (finished it this week), you should.

Its about the evolution of the human species over the next million years turning on very specific events in Ecuador in the year 1986, and the common ancestor of all future humanity.

In his unique style, of course.

That one is Vonnegut's sleeper masterpiece - the choice of narrator was especially clever. How can you have a narrator narrate a million-year-spanning story? Vonnegut figured it out.

Another good read is "One Hundred Years of Solitude" by Gabriel Garcia. Its about the birth and death of an entire family line, flowing through the wars, migrations and incest that revolved around it (atleast thats my interpretation :)).

The most important question is ofcourse, what do I have to do to be one of those common ancestors and have my dna be part of every human alive? Is it just having as many wives as possible like solomon and khan, or is there a better strategy?

Well, your number of children is linear, but your number of descendants is exponential. For the CS students, what this means is that the number of children you have personally, even assuming they all reproduce, rapidly becomes immaterial next to the number of your descendants.

The only reason having more children might be beneficial is if it significantly increases the odds that they personally, or their children successfully reproduce. If you have some other way of boosting those odds -- say, by being a successful parent to a smaller number of children -- that's just as good in the long run.

But each generation only carries half the DNA of the previous one. So after 5 generations there is a vanishingly small chance that anyone after that will still carry your DNA, with the exception of male lineage -- there you know that the Y chromosome has made it through.

If you have several children, and raise them to well-adjusted adults who have children of their own, the chances are already very good. Assuming your average descendant has more than one child, and inbreeding is negligible, the number of descendants increases exponentially by generation. So the probability that none of your descendants in a given generation breed falls off rapidly.

Of course, if you can father hundreds of children, that would also work. But you would probably run a much higher risk of being killed or imprisoned before you can spread your genes around much.

Cushman's answer is the correct one. You simply need to have some children. It doesn't matter how many you have as exponential effects will quickly swamp any linear effects of having more than your share now.

What determines if you are a common ancestor is the particular genes you carry: do they give the carrier enhanced survival benefits? I can see someone like Kobe Bryant or Brad Pitt being a common ancestor.

Edit: thinking about it more, there is something you can do: have as many children as you can with as many genetically diverse women as possible. The key here is diversity, you want to pair your genes up with as wide a range of genes as possible. The reasoning is that we can't predict what environment will be exerting selective pressures in the future. Thus the important factor is genetic diversity. This is basically hedging against unknown changes in the environment.

Also, teach your kids to not be racist, so that they will do the same and pass that tendency onto their kids...

I know a guy that donates to the sperm bank non-stop in Canada. Since it is illegal to pay for sperm here, he's got to be contributing a significant percentage of the banks' resources. He figures he has at least 100 children at this point.

well, I guess that's 1 way to spread your seed across humanity...

Have as many children as possible and encourage them all to breed prolifically.

A friend is on her 14th.

Get busy.

What is the probability that a descendent carries even at least one gene from the "Most Recent Common Ancestor"?

The human genome has only 20,000 protein-coding genes (which comprise 1-2% of human DNA). I'll be generous and use the 1% figure to assume that human DNA has about 2e6 "genes" (protein-coding or otherwise).

After 100 generations:

Probability any one gene comes from MRCA: 1/(2^100). Probability any one gene does not come from MRCA = 1 - 1/(2^100) Probability NO gemes come from MRCA = (1 - 1/(2^100))^(2^6) = 0.9999999999999999999999999999495129020658552444536494

Probability at least one gene comes from MRCA = 5.05 × 10^-29

I think that you have confused mutation with gene in your initial assertion.

There is probably only a few percent of variation between all of your 2^100 ancestors genomes (the majority of whom will be related), so protein coding regions of your genome and your MRCA are actually likely to be very similar.

Now if that MRCA had a specific mutation, the chances of your inheriting that specific mutation are probably low, but depend on that mutations prevalence in the population as well as whether the mutation is deleterious or not.

100 generations is very few in terms of changes within the genetic make up of a population under normal circumstances.

>What is the probability that a descendent carries even at least one gene from the "Most Recent Common Ancestor"?

If you think about it, its very nearly 100%. The fact that he is the MRCA means that a particular gene of his conferred an enhanced survival advantage. This enhanced gene is likely to exist in all of humanity currently living.

> That's why everyone alive in the Holy Land at the time of Jesus would have been able to claim David for an ancestor.

This really threw me for a while, as it seemed to be an obviously false statement. Until I realized the author had switched contexts on me: Jesus claimed male ancestry, but this statement is including ancestry from both male and female lines. So it seems overall believable, however I still see many provably false assumptions in this article.

* The population of the Holy Land was a constant 1 million people for 35 generations. Assumes no population growth. (false)

* No imigrants (false, see next bullet)

* No intermarrying with other cultures (false, because this intermarriage is often cited in the Bible as a reason people turned to other gods)

> More specifically, imagine the simplest case of a population of a constant size - say a million (the approximate size of the Holy Land at the time of Jesus).

I'm just quoting this to show that the author asks us to assume a constant size population

I'm certain that there were thousands of people in Palestine that could have claimed an unbroken ancestry from David. But based on all the flaws in this article, I don't trust the assertion that everyone in the area can claim an unbroken line (even including female ancestors).

Jon Kleinberg, Professor of Computer Science at Cornell University on the pigeonhole principle: http://edge.org/response-detail/2890/what-is-your-favorite-d...

> If you go back on average 1.77 times further again (35 generations) everyone in the population will have exactly the same set of common ancestors

The problem is, different people have different life span. And different people can share the same parent.

And sometimes in extreme cases, father - daughter love?

There's a method to estimate that: http://en.wikipedia.org/wiki/Most_recent_common_ancestor#MRC...

"Studies have used computer modelling to estimate that the MRCA of modern humans lived between 5,000 to 2,000 years ago."

Perhaps this person:

Person Who Will One Day Become Warlord-Ruler Of What Was Once Nebraska Born In Omaha Hospital


I may be missing something but it doesn't seem necessarily true. Our last common ancestor may have already died and we may not get another with all the divisions that exist, or space travel that may happen (ie. we don't and won't breed at random).

So in 3000 years we'll all be having sex with our relatives. Good to know!

Or more importantly, we're already having sex with our distant relatives!

Well, some of us are.

We already are.

There's a cheery thought!

Seriously though, what about if you marry someone from a different country? I'd imagine the chances are somewhat lower.

Never mind a different country - if you married someone from a different species they're still related to you. The only difference is the number of generations you need to go back to find the common ancestor.

Are we sure abiogenesis only happened once? Given how quickly life appeared once the conditions were right, it doesn't seem too implausible that the lightning strike might have happened in two different tidal pools on opposite sides of the planet, and it seems just vaguely plausible that there would be (bacterial) descendants of each that have no interbreeding in their ancestry.

I asked this in a thread on Slashdot once, and got a really good answer. Basically, there are a number of molecules that can have a left or right chirality. These happened by random chance at the beginning instances of abiogenesis, and were replicated faithfully since. So if it happened twice, a number of those molecules (or larger structures) would be backwards. From a macro perspective, things like the heart being on the left side, or the direction of other internal organs (i.e. appendix on the right side). At the molecular level, things like the spiral of DNA. There is some more information in Wikipedia, under abiogenesis and homochirality.

AFAIK all known life shares common ancestry. That doesn't mean life couldn't have arisen twice, but if it did, and if its descendants still exist, we haven't found them.

The chances of what? They are still your distant relative, like everyone on earth. Someone from a different country is probably more distantly related, but unless they're a humanoid alien, they're still related to you.

I guess there's not much point responding as the censor brigade came by and downvoted the hell out of my comment. It was a serious question, and I thank you for responding with a serious answer.

I don't think it was a censor bridge, it was a "this person didn't read the article" brigade. The point of the article was that everyone is related to everyone on a distant enough timescale. The person you responded to initially was making the point that everyone is your incredibly distant relative. Being in another country doesn't change that. 35 generations back, (mathematically) everyone has the same common ancestor.

Honestly, I don't really care if we are... I just don't want to know about it.. ignorance is bliss :)

> In 3000 years someone alive today will be the common ancestor of all humanity

The title is very misleading. It's not true about any single person, unless there's a species bottleneck with only one survivor, and then there's a practical problem.

It would be more accurate to say that all those living 3000 years from now will have their genetic roots in all those living in the present. But if that had been the headline, no one would read the article.

How about this: "In 3000 years everyone alive today will be the common ancestor of all humanity". True, but not very exciting.

The title is accurate. The article states explicitly that 3000 years ago the common ancestor of all of humanity existed. It's just that 3000 years ago wasn't the point where one and only one common ancestor existed; some 80% of the population may have carried that distinction.

> The title is accurate. The article states explicitly that 3000 years ago the common ancestor of all of humanity existed.

The title -- "In 3000 years someone alive today will be the common ancestor of all humanity" -- is not accurate. There was no single "common ancestor", because modern humans owe their genetic inheritance to multiple sources. This will be true in the future as well.

I'm not sure I understand the relevance of your point. If you're saying that there is no single common ancestor, but multiple common ancestors at the timespan of 3000 years, then yes that is true. But that doesn't invalidate the fact that any of them is the (perhaps better stated as "a") common ancestor.

> But that doesn't invalidate the fact that any of them is the (perhaps better stated as "a") common ancestor.

The title clearly suggests a single ancestor, an individual.

Very interesting! If I didn't misread, a better title would be "In 3000 years almost everyone alive today will be a common ancestor of all humanity."

From the story: "In fact about 80% of the people at that time in the past will be the ancestors of everyone in the present. The remaining 20% are those who have had no children, or whose children have had no children, and so on - in other words, people who were genetic dead-ends."

This puts a whole new perspective on the often quotes statistics about Genghis Khan's progeny.

So it seems that recessive traits, like blue eyes, will likely be bred out of humanity in relatively short order.

At least until full blown reproductive genetic manipulation comes into effect.

You need to (re)read Mendel. Recessive traits and dominant traits stay at a constant fraction within a population (absent selective pressures).

That's assuming sexual selection doesn't play a role.

We don't have conquerors and kings anymore, in most parts of the world.

The common ancestor would probably have to be the ancestor of a very successful nation that would rule (a big part of) the world, and no current world ruling nations let their governors reproduce at will, like they did in the past.

Currently the world is full of Genghis Khan descendants, but also, there are no Genghis Khan equivalents anymore.

Simply remember the Monika Lewinsky scandal.

What I am more interested in is: will someone who is alive in 3000 years be a common ancestor of all humanity?

Quoting the article: "And one can, of course, project this model into the future, too. The maths tells us that in 3,000 years someone alive today will be the common ancestor of all humanity.

A few thousand years after that, 80% of us (those who leave children who in turn leave children, and so on) will be ancestors of all humanity. What an inheritance!"

Heh =). But what I mean is something like, will there be someone alive in 3000 years that is about 2000 years old.

The concept is totally flawed, because the probability of inbreeding goes up as you go back in the generations, so:

Probability your parents are the same person: 0

Probability one of your grandparents is the same person (i.e. your mom's mom is your dad's dad's wife): very low

But then you get up to the point where you have 10k or 10m ancestors and those numbers start to skyrocket.... especially given how relatively geographically constrained we are.

So if you go back 3000 years, you'll have whatever 200 million (whatever the global population was in 2000 B.C.) ancestors. But that number will be chock full of "repeats". In fact you might only have 20 million "unique" ancestors in that era.

You'd need to model migration to actually figure out when you could reasonably expect that everyone would be somehow descended from you.

But even if you completely buy in to the premise of the article, they still get the analysis wrong.

It's not that someone will be the common ancestor, it's that everyone¹ will be a common ancestor of all humanity.

¹ who breeds and whose children breed, and their children breed...

> It's not that someone will be the common ancestor, it's that everyone¹ will be a common ancestor of all humanity.

Yes, that's actually stated very pointedly in the article.

Haha, I cannot believe that they could not get a better picture of the guy in the article than they did.

Picture: http://news.bbcimg.co.uk/media/images/62401000/jpg/_62401882...

It's a consoling thought for the childless... almost all the branches of the vine end.

I think you misread (or didn't read the entire article). The article states that the majority of the "branches" will live as long as humanity itself. I am currently childless and did not find this a consoling thought (quoted from the article):

"In fact about 80% of the people at that time in the past will be the ancestors of everyone in the present. The remaining 20% are those who have had no children, or whose children have had no children, and so on - in other words, people who were genetic dead-ends. [...] A few thousand years after that, 80% of us (those who leave children who in turn leave children, and so on) will be ancestors of all humanity. What an inheritance!"

No, it is true that eventually most branches will end. It's just on the timespan of 3000 years, 80% of the population will likely be a common ancestor. But if you extrapolate back far enough, there will be one and only one. The only way branches can survive forever is if you assume that all genes have essentially the same chances of survival. This obviously isn't true. Even the smallest enhancement will quickly spread throughout the population.

I am curious when the most recent unique common ancestor of humanity existed. Would we consider him human now or something in between?

Or would have been, if genetic manipulation technology hadn't been invented.

Yes, and that person will be the inventor of some robot or other.

Good to see a More or Less story on HN. For those who don't follow it, it is basically either a UK current affairs show for the mildly autistic, or a regular open university maths and economics lecture - http://www.bbc.co.uk/programmes/b006qshd

I really hate this trend for describing anything somewhat intellectual as 'autistic'.

Yes, but psychologists love it -- it's bread on their table. Anyone sufficiently to the right of the mean I.Q. can be diagnosed on the autism spectrum, and be put into pointless therapy.

I don't really understand this view of therapy. In my experience, it's something you choose for yourself, because you recognize the need. The odds that you receive a psychiatric evaluation against your will and be compelled into therapy are amazingly slim. Especially for something like 'autism-spectrum' disorders, where the majority of sufferers appear to be high-functioning.

> I don't really understand this view of therapy. In my experience, it's something you choose for yourself, because you recognize the need.

That would be nice, but it doesn't reflect reality. In schools, children are frequently given autism spectrum diagnoses against their better interests, or wishes, or the wishes of their parents (but not always -- sometimes parents force these things on their children). But the patient's wishes are often the lowest priority.

Ideally, people would volunteer for therapy solely on issues they choose for themselves. But this isn't how clinical psychology works in modern times. Schools have a vested interest in getting diagnoses, because special-education funds are only available for those with a diagnosis.

The reason Asperger's is being abandoned is because it was applied in exactly the way described above, until everyone realized it was a scam -- even the therapists who benefited the most. Now it's slated for removal from the next edition of the DSM, and further, the diagnosis criteria for autism spectrum is being reworked to prevent another epidemic of nonsense diagnoses such as we have just seen.

> The odds that you receive a psychiatric evaluation against your will and be compelled into therapy are amazingly slim.

On the contrary, it's an everyday occurrence, especially among children, who aren't mature enough to realize that psychologists aren't doctors.

> Especially for something like 'autism-spectrum' disorders, where the majority of sufferers appear to be high-functioning.

Yes, and that is the present problem area -- bogus diagnoses, using vague criteria that can be applied to nearly anyone, with obvious advantages to everyone except the patient.

Mental health professionals, aware that autism spectrum diagnoses are out of control and no longer have any connection to reality, have joined an American Psychological Association task force charged with redefining ASD to stem the tide of nonsense diagnoses. One of those behind the redefinition effort (Dr. Fred Volkmar, director of the Child Study Center at the Yale School of Medicine) says of the diagnosis surge, "We would nip it in the bud."

You seem to be referring to info and quotes from this NY Times article


Dr. Volkmar --who you quoted-- is actually against the redefinition and is arguing that the redefinition hides people who do suffer from genuine conditions.

Here is a Yale interview of Dr. Volkmar that left me with a far different impression than the NY Times article:


And this:


> Dr. Volkmar --who you quoted-- is actually against the redefinition and is arguing that the redefinition hides people who do suffer from genuine conditions.

So that would be why Volkmar is serving on a task force charged with responsiblity for redefining ASD? That would be why he has been quoted as saying his committee would address the ASD diagnosis epidemic and "nip it in the bud"?


Quote: "The changes would narrow the diagnosis so much that it could effectively end the autism surge, said Dr. Fred R. Volkmar, director of the Child Study Center at the Yale School of Medicine and an author of the new analysis of the proposal. “We would nip it in the bud.”" (Emphasis added.)

To make this perfectly clear, Dr. Volkmar is an advocate of this change, and is one of the leaders of the activity.

"... Asperger's is being abandoned.... Now it's slated for removal from the next edition of the DSM"

REALLY??! Wow. I sure thought I was seeing a bunch of misguided hullabaloo, but I'm surprised to see the "industry" itself is aware of it and addressing it. Do you have a link or any kind of substantiation?

> Do you have a link or any kind of substantiation?


The above is just one of the many links to this topic -- here's another:


It's important to say that DSM-V (the new edition of the diagnostic manual) is being compiled in secret, contrary to the open nature of science, and demonstrating that the psychological community are circling the wagons against what is certain to be a storm of criticism once it's published (slated for May 2013).

One of the tidbits that has slipped out of the secret process is that grief over the loss of a loved one will qualify for a depression diagnosis, which will allow the prescribing of drugs to treat this new "mental illness."

Further reading: http://arachnoid.com/trouble_with_psychology

    >Asperger’s syndrome... will be folded into a single broad diagnosis, autism spectrum disorder
^ FTA quoted as a source. It's not going anywhere, just re-labelling. There are definitely things behind AS, it's certainly not all just 'hullabaloo', even if a lot of cases might be.

> It's not going anywhere, just re-labelling.

Not really. Two things are happening:

1. Asperger's is being dropped as a diagnosis.

2. ASD diagnostic criteria are being redefined with the specific aim of reducing the number of diagnoses, to avoid another epidemic of nonsense treatments of people who, apart from being intelligent, are otherwise normal.

Further reading: http://www.nytimes.com/2012/01/20/health/research/new-autism...

> There are definitely things behind AS ...

Yes, there certainly are. It's a gold mine for clinical psychology, because anyone to the right of the mean population I.Q. can be diagnosed using the present criteria, and because of this kind of abuse, it's being abandoned -- it's just too tempting to apply it to everyone. As one of its prominent critics has said, "It's not an evidence-based term."

Didn't realize I'd ended up on Conspiracy Theory News.

What? Psychologists have acknowledged what I said -- I didn't make it up. Psychologists now see that the Asperger's diagnosis epidemic had no basis in reality -- that's why Asperger's is being abandoned.

Further reading: http://www.nytimes.com/2009/11/03/health/03asperger.html?pag...

It's effectively being reclassified as a form of autism, which is what neurologists have been calling it for years now.

You're being incoherent--why on earth would psychologists "abandon" a diagnosis that they "love" because it's "bread on their table"?

On second thought, don't bother answering--I already waste too much time jousting with conspiracy theorists on HN.

> It's effectively being reclassified as a form of autism

That's like saying astrology is being reclassified as a form of astronomy. Something like that happened, but we all know the outcome of that battle.

> why on earth would psychologists "abandon" a diagnosis that they "love" because it's "bread on their table"?

Because of public exposure. Because of articles like this one:


Psychologists realized their behavior was obviously and solely self-serving, even to non-specialists. So, just as with Recovered Memory Therapy, they called a halt to something that could only do them more harm.

> I already waste too much time jousting with conspiracy theorists on HN.

That only makes sense if psychologists are the conspiracy theorists, because it is psychologists who are demanding this change. Case in point -- Theodore Insel, sitting director of the NIMH, calls for the same change that I do:


Quote: "In most areas of medicine, doctors have historically tried to glean something about the underlying cause of a patient’s illness before figuring out a treatment that addresses the source of the problem. When it came to mental or behavioral disorders in the past, however, no physical cause was detectable so the problem was long assumed by doctors to be solely “mental,” and psychological therapies followed suit.

Today scientific approaches based on modern biology, neuroscience and genomics are replacing nearly a century of purely psychological theories, yielding new approaches to the treatment of mental illnesses."

Sound familiar?

I think you have a point buried in there somewhere, but you're overstating it with so much hyperbole that you come across as a crank. Sort of like the LaRoucheites who used to accost people, panicked that Dick Cheney was going to nuke Iran.

> you're overstating it with so much hyperbole that you come across as a crank.

Tell that to Dr. Insel, sitting director of the NIMH, who I quoted to make my point.

Dr. Insel's quote wasn't the part that sounded crank-ish.

Wasn't meaning it as intellectual, was more meaning it in as obsessed with pattern and order.

Yeah something like Freakonomics (Tim Harford calls himself the undercover economist) and with equally admirable production qualities. I mentioned More or Less as my podcast recommendation on the very last HNpod actually.

glad to see this is still around.. enjoyed it a lot, i thought it was gone after the 3 month hiatus.

Not if people alive today are still alive in 3000 years, which isn't terribly likely but not wholly out of the question either.

If they had kids today, and then stayed alive, it would work out pretty much the same. Except it would be fairly crowded.

You better hope it will be me!

Except that there is zero empirical evidence that the Bible figure "Jesus" actually existed...

However, the question of the existence of Jesus as a historical figure should be distinguished from discussions about the historicity of specific episodes in the gospels, the chronology they present, or theological issues regarding his divinity.[360] A number of historical non-Christian documents, such as Jewish and Greco-Roman sources, have been used in historical analyses of the existence of Jesus.[357]

The large majority of modern historians agree that Jesus existed and regard events such as his baptism and his crucifixion as historical.


Given that the article makes it clear in the first sentence that this is about more than the specific example of Jesus that's relevant how?

not mentioning Jesus was never a common ancestor to all people, even in the bible.

Adam and Eve were (and I guess Noah?)

The question is about the claim that Jesus was a descendent of David rather than people being a descendent of him.

Also, from where did Jesus get his Y chromosome?

If you take the bible literally and assume that God is the father then is the fact Jesus has a Y chromosome proof that God is a man?

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