Tracing the Journey of Man

Nothing technical today, sorry 🙁

Went to a fascinating lecture last night with friends of the family (the Bowras).  It was a part of National Geographic's "National Geographic Live!" series.  The NG Live series is a series of three or four lectures given every spring that presents National Geographic lecturers presenting information about stuff on which the society is working.  The Bowra's have invited me to come along with them to a couple of the previous lectures in the series, the one with Robert Ballard (as in the guy who found the Titanic) was especially fascinating.

Last night's lecture was Spencer Wells presenting the materiel in his book (and NatGio special) Tracing the Journey of Man.

It was a fascinating lecture.  Spencer Well's is one of the people who did the research that determined that all humans descend from a pool of approximately 2000 individuals who lived in Africa sometime about 60,000 years ago.

He figured this out by measuring the amount of genetic variation in human beings - what I hadn't realized is that humans are very different from other primates - the genetic diversity in most primates is around 25%, while humans have only a two or three percent genetic diversity.  The only way that they could explain this is that there had to have been a tiny pool of original ancestors for all humans alive on the earth.

By tracing genetic markers that live on the Y chromosome, his team was also able to determine that human beings actually spread from two different locations - one in Africa, the other, about a thousand or so years later from Australia.  His team figured that about 60,000 a group of people left Africa and followed the coastline across the Indian subcontinent and then crossed a land bridge into Australia.  From there, humans spread out from both population centers to cover the world (that took about 15,000 years).

One of the things I loved was how he figured this spread out.  He couldn't find any oral tradition of a great journey in the tales of the Australian Aborigines, so he figured that if they HAD made the journey, he'd be able to find genetic markers along the route.

And in fact, when he went to India and started sampling the population, he discovered a genetic marker that the people he sampled shared in common with the Aborigines.  And that marker dated from somewhere about 55,000 years ago.

So he deduced a testable theory from his hypothesis, then performed the experiment and confirmed it.  Very, very cool.

My favorite moment was during the Q&A question when someone asked: "Have you had any resistance from local authorities to your research?  And can you present it in Kansas?".  That got a HUGE round of applause.

My biggest complaint about it was that the last 1/3 of the lecture was essentially a sales pitch for NatGio's new Genographic Project.

Comments (10)

  1. Anonymous says:

    You might also like "The Seven Daughters of Eve" by Bryan Sykes. Interesting read.

  2. Anonymous says:

    "Guns, Germs, and Steel" is an excellent book as well that briefly covers that topic. It then details the spread of humans and their technological advancements based on the natural resources available in their newfound homelands.

  3. Anonymous says:

    This is extremely interesting and a complementary story to The Seven Sisters of Eve regarding the tracing of the history of mitochondrial DNA, which only comes from the mother, to determine maternal lineage back to a small group. It would be interesting to compare the two studies.

    One thing that disappoints me Larry is the glee in the laughter at the "And can you present it in Kansas" question. I am a staunch believer in evolution but find that it is all too often that people must put down a group especially since the put-down depends on assuming that so many Americans (Red Staters?) are dumb, anti-scientific and irrational idiots. I’m sure many people find the feeling of superiority that comes from this satisifying, but you seem smarter than that.

    Again, just disappointed that both left and right must be so condescending.

  4. Disappointed: I’m sorry that it sounded like there was glee – the audience clearly liked the way the question was phrased.

    What I forgot to include was Spencer’s answer. Which was essentially that there’s nothing in his analysis that is incompatible with a belief in ID. His analyis requires that there be a single mutation (or set of mutations) in that group of 2000 individuals that caused homo sapiens (which had been around for over 100,000 years before this) to suddenly take a "Great Leap Forward" – they seemingly instantly developed language, art, high level toolmaking, etc.

    Now, having said that, the entire analysis is based on a fundimental assumption of evolutionary principals that are incompatible with creationism (in psrticular). But they’re NOT incompatible with ID (which, at its essence, can be considered "evolution with a helping hand"). His data is also not incompatible with the story related in James Hogan’s "Giants Star" trilogy, either.

    Going WAY off topic, personally I find it truly unfortunate that the Kansas State Board of Education has decided to ignore several hundreds of years of scientific method in favor of a "theory" that isn’t (IMHO ID is a critique of evolution, under no circumstances does it stand on its own as a scientific theory, since it cannot be falsified, nor can it predict experimental results).

    That’s a part of why the story about finding the genetic markers in the Indian subcontinent was so fascinating. He developed a theory (that humans migrated from Africa to Australia along the costline and over the land bridge to Australia). That theory was verifiable, so he created an experiment to verify it (the experiment was that if he sampled people living in the subcontinent of India he’d be able to find a genetic marker that they shared in common with the Aborigines, and that it would date to about the right time line). He then performed his experiment and his theory was confirmed.

  5. Anonymous says:

    Disappointed: Welcome to Washington state, where anyone who doesn’t live in the city must be a hick and a rube. 🙁

    Larry: As a Kansan ex-pat 😉 and having a degree in Biochem from Wichita State University in Wichita, Kansas and having a high school diploma (15 years old this spring) I can authoritatively say that evolution *IS* being taught in Kansas.

    re: ID and Evolution not being incompatible. ID the way it is used today usually represents creationism. If you take the ID people at face value, then no it doesn’t seem incompatible to me. In fact a book by my former boss is all about ID, in a manner of speaking. "At Home in the Universe" by Stuart Kauffman is about self-organization and evolution. Stu doesn’t point to a specific deity as being responsible for evolution, but he does think that some of the emergent properties of living creatures hint that the specific evolutionary path that we took was inevitable. Which an ID believer could interpret as "by design".

    Which isn’t to say that the ID people aren’t nutcakes, they are battier than Bruce Wayne. In the specific instance of the Kansas board of education, it looks like the ID people are trying to soften the definition of ‘science’. Removing ‘natural" from the "natural explanation" deinfition. Which opens the door to lots of non-natural explanations for how things work.

  6. I’m sure that evolution is being taught in Kansas.

    I’m also sure that there are a few grandstanding nutcases (and I mean this in the most respectful fashion possible) who have chosen to use the state Board of Education as their personal pulpit to expound their religious views.

    I believe it was the current(last?) governor of Kansas who complained about the last BoE that they were making his state look like a bunch of morons?

  7. Anonymous says:


    Thanks for the response. I’m in complete agreement regarding the school board’s decision. At some level I suppose that ID can be reduced, as you say, to the idea of a helping hand only. In this case, there would be no way to distinguish between a helping hand and luck (mutations and other circumstances). At that point, ID only introduces a complexity which can not be proved one way or the other. Occam’s razor would dictate that random evolution is more sensible of an explanation.

    As such, ID can only be used as a pseudo-scientific fig leaf (pardon the reference) over Creationism.

    I firmly believe in the science behind evolution but this is my faith in science. I can only respect (if disagree) with those who believe otherwise.

    My point was the respect and once again I appreciate your taking the time to reply.

  8. Anonymous says:

    Oh no. I’m pretty sure I still have some old school ID somewhere, and now I’d better find it and burn it.

  9. Anonymous says:

    I should probably look it up myself, but was there really a land bridge to Australia only 60,000 years ago? That goes against my understanding of land formation or continental movement, and I can’t see ocean levels or an ice age affecting that.

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