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Rival Anthropologists Donald Johanson and Richard Leakey Reunite after 30-Year Rift

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Donald Johanson and Richard LeakeyOn May 5 famed paleoanthropologists Donald Johanson and Richard Leakey convened at the American Museum of Natural History in New York City to discuss human origins. It is the first time Leakey and Johanson–longtime rivals–have shared a stage since a public falling out in 1981. Viewers in the live audience and those who tuned in to the webcast tweeted the discussion and uploaded photos to Facebook, so I decided to use Storify to document this historic event.  


[View the story "Rival Anthropologists Donald Johanson and Richard Leakey Reunite after 30-Year Rift" on Storify]

 Photo of Richard Leakey and Donald Johanson by Frank Kollman

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  1. 1. JamesDavis 7:35 am 05/8/2011

    I think these guys evolved from parrots. How can one species change its DNA to a whole new species and still maintain their original species? And why didn’t all the chimp species change their DNA over to human and become human, and why is human DNA 1% different than current chimp DNA. I was always taught that 1%, when it comes to DNA, is the difference between night and day and that would make them two totally different species. But, the big question remains: Why did some chimps switch their DNA to become human and the other chimps didn’t?

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  2. 2. DaveG 8:17 am 05/8/2011

    Thats the good question James. The answer is that chimp and human ancestors became isolated from each other for a period of time. Over time they became too different, in terms of DNA, and/or behavior, to interbreed. Thats the 5 second answer — much is written and the process of speciation.

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  3. 3. DaveG 8:19 am 05/8/2011

    Sorry, that should say ‘much is written on the process of speciation.’ Next time I’ll finish my coffee first.

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  4. 4. JamesDavis 8:57 am 05/8/2011

    Okay, Dave, I’m about 1% into that, but what caused the chimps that got isolated from the others to change their DNA to a whole new species and how did they do it while some of them maintained their original breed within that species that got isolated? Why did some choose to change to a whole new species and some choose to stay within their original species? Big question: How did they change their DNA to a full 1% different that allowed them to become a whole new species?

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  5. 5. lowndesw 11:28 am 05/8/2011

    James, consider this scenario: How did monkeys get to be so fast running in the ground?? Answer: Lions ate the slowest ones. Over thousands of years with only the fastest ones surviving to reproduce, the entire group got faster.

    Another way to look at it: we (humans) are all a little different from each other: faster, slower, dark skin, light skin, tall, short, blood group A, blood group O, etc. All of the traits are controlled by very small differences in our genetics. We all carry these differences, we are all just a little different from each other in many ways, but similar, too, enough to reproduce.

    If the climate were to change in the area you live in, say colder (and you did not have all of our modern conveniences, just living in the woods) then gradually over long periods of time, the ones better suited to cold would survive more than the least suited. Those would be the fair skinned (better able to produce vitamin A), shorter limbs (body heat efficiency), etc. Over time our DNA (genetics) would change (or be changed) by the elimination of less well suited and enhancement of the better suited for survival for those conditions.

    If the weather got warmer, unprotected (fewer clothes) darker skin would better protect from UV and skin cancer. Over long periods of time, conditions would gradually select the best suited for survival.

    There are of course many, many factors in play, and they change with conditions. Intelligence seems to be a constant.

    It’s all kind of like the odds in Vegas that are just slightly in favor of the House. Some people will win money sometimes, but over time the House makes enough to pay huge payrolls AND invest in newer and bigger casinos.

    The concept is very simple. You see it every day all around you. Businesses rise and fall. Some are better suited for the conditions and/or make good decisions and they rise. Some are not wise (smart), make poor decisions and fail. In the 1960′s Marchant mechanical calculators were devastated by the advent of electronic calculators. They did not survive but the technology of our society was improved.

    Wolves were reintroduced into Yellowstone to improve the herds of bison and elk, by eliminating the weakest and sick. Survival of the fittest.

    Some people say that our modern society is eliminating these means of improving our "herd" by making it possible for the weaker, illness susceptible, and less wise to survive and reproduce. Some say that people with views such as yours are proof of that.

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  6. 6. robert schmidt 12:23 pm 05/8/2011

    @JamesDavis, chimps did not switch their DNA to become humans, chimps and humans have a common ancestor. It is like asking how your brother or sister switched their DNA to become you. Also, species don’t "switch" their DNA. Mutations appear in the genetic code as a result of copying errors. If those changes help the organism they get passed on to the next generation. If they hinder, they don’t. One common type of error is when a gene is copied twice. This allows for changes to one copy of the gene while the other continues to go its job. Similarly a virus may insert it’s DNA into the host’s DNA. This DNA can then undergo changes with no decrease in function to the host as the host wasn’t using that code for anything anyway.

    So, if modern humans and chimps have the same ancestor why do we look so different? In the case of humans and chimps, it is because modern humans and modern chimps lived in different environments. For example, walking upright is great on the savannah but not so good in dense jungle, especially if it costs you your ability to climb. Once you are walking on two legs your hands are then free to do other things such as work with tools, which benefits from having a bigger brain. So pressures come from the environment but also from within ourselves. Another example is the competition for resources of our brain and gut. Both types of tissues are very expensive. To consume plants like grasses takes a powerful and complex digestive system. Compare a human gut with that of a cow. Whereas eating fruit and meat is much simpler. But it takes much more brain power to know when a fruit is ripe, or how to hunt and kill another animal than it does to stalk and kill a blade of grass.

    You seem to be under the impression that one day there was a chimp that gave birth to a modern human. Of course that never happened. From one generation to the next you would be hard pressed to notice much of a change at all. It is only when you compare individuals that have been genetically separated for hundreds-of-thousands or millions of years that you see the large scale changes that define species. It is very similar to the changes from child to adult. There is no single point in time in which that happens. From one hour to the next a person pretty much looks the same. It is only when you look at photos taken months or years apart do you see the gradual metamorphosis.

    All your questions are easily answered by a simple internet search. Please read "The Greatest Show On Earth" by Richard Dawkins. It will answer all your questions.

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  7. 7. JamesDavis 7:17 am 05/9/2011

    ‘robert schmidt’ – You and I have been going at this for a long time, and you know that I probably watch the same history and science channel that you do and I also, probably, read the same scientific magazines that you do. I probably even read the same auto magazines that you do. You also know that SciAm has a bad habit at allowing their, just out of school and low grade scientists, produce misinformation, and sometimes, really crappy articles, but yet, I still read the magazine and so do you. I call you on some comments and you call me on some comments and we both learn from it.

    My point is, Robert: SciAm says that science is going to be more visible and teach their research with more accuracy, yet, SciAm seems to steer away from accurate reports. If I remember right, you have even complained about this too…several times. I know that your information is accurate and well explained so a non-scientist can understand it and you do a great job with your research to ensure there is few to no misinformation. So why is it so hard for SciAm to do the same thing? For a young person coming up who may be interested in science, SciAm seems not to be the magazine they should turn to for accurate information and SciAm even allows these spammers advertise their businesses in the comment section, and even though they have got a lot of complaints about it, they still allow their comment section to be overpopulated with spam from these businesses.

    Thank you for clearing all that up for me, and for people who may be just starting to read this magazine.

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  8. 8. DaveG 11:44 am 05/9/2011

    James, you seem have rejected the reasonable assertions of several posters here. Do you have an alternate point of you would like to share?
    You have difficulty accepting that a species can change over many thousands of generations, and that isolated populations can diverge. What is the alternate point of view? Perhaps chimps and humans are still the same species?

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  9. 9. robert schmidt 9:54 pm 05/9/2011

    @JamesDavis, "My point is, Robert: SciAm says that science is going to be more visible and teach their research with more accuracy, yet, SciAm seems to steer away from accurate reports." I don’t believe that sciam’s mandate is to teach science. It is a science news publication so its focus is on what is happening in science and what is happening in the world from a scientific perspective. It assumes a certain degree of scientific literacy. If people need more info there are a number of sources they can get it including sciam’s sister publication Nature. I don’t come to sciam to have a particular hypothesis proven or learn the new definitive state of the universe. I come to see what is going on, who is studying what, how far research has gone in various fields, and to get a different perspective on current events than is possible with standard media. I have said this before, there generally is not enough info in the articles here to either prove or disprove the central point of the article. For that you will have to look at the actual peer reviewed paper. Just think of Sciam as the teaser for Nature.

    I am not aware of sciam deliberately producing misinformation but they do have blogs which are just opinions. Opinions are just that and should be read in that context.

    One has to ask though, if you are so interested in the subject of evolution, as you seem to post comments on evolution articles often enough, and given that the subject of evolution is probably one of the most documented and most accessible of all scientific theories, why you still don’t even understand the basics? It really gives us the impression that you aren’t interested in evolution at all, or understanding science in general, rather you seem to just want to preach your ideology. If I have even the slightest interest in something, I read books, watch documentaries, I may even model it on my computer, but you don’t seem to have read even an introductory book on genetics, evolution or the scientific method. How do you account for your interest in the subject but lack of effort to understand it?

    I do agree that the sciam website is somewhat sub-standard. They need to do more to deliver a quality product. The spammers are just laughing at them. Meanwhile sciam has no problem yanking a comment that is a little on the critical side. Better to be a spammer than passionate I guess.

    p.s. I don’t read auto magazines, I don’t get cable TV and sciam is the only science mag I read regularly.

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