john hawks weblog

paleoanthropology, genetics and evolution

cloning

  • Mailbag: Neandertal backbreeding

    Thu, 2010-09-16 13:07 -- John Hawks

    In your blog, you have commented on the prospect of re-creating
    a neandertal from a "completed" genome.....I agree with your views
    and predictions.

    However, given the apparent widespread occurrence of small pieces
    of the neandertal genome in contemporary humans, there should be
    a large variability in the fraction of each person's genome which he/she
    shares with at least the small number of neandertals whose DNA has
    been sampled.

    And though one could argue that ethics would be trampled, one could
    selectively breed exisiting humans to enhance their complement of
    neandertal genes. Not that I am suggesting this should be done, but
    such breeding could be entirely voluntary, may have already occurred,
    and would overcome at least some "Jurassic Park" and Frankensteinian
    objections to the enterprise??

    You bet -- that's not only plausible in principle, it's exactly what people are trying to do with cattle to backbreed something like aurochsen.

    The success (not withstanding the time required) hangs on the distribution of Neandertal variation in the current genome. We don't know yet how clustered it is -- is it a 3 percent average, but people have random parts, or is it that most people share the same 3 percent? If it's more scattered, then a larger representation of the Neandertal genome still exists, distributed among many people; if not, we may not be able to get more than a few percent of a Neandertal by backbreeding.

    Tags: 
    ethics
    biotech
    Neandertal DNA
    conservation
    cloning
    extinction

  • Frozen zoo

    Sun, 2010-08-29 08:30 -- John Hawks

    The Observer has a nice article describing the "Frozen Zoo" of samples kept by the San Diego Zoo Institute for Conservation Research.

    Dr Oliver Ryder, the geneticist who heads the Frozen Zoo programme, welcomes the news of Loring's work, which itself built on a breakthrough in 2007 by Japanese scientist Shinya Yamanaka. For Ryder it is confirmation that the zoo's founding as a sort of "bet" on the science of the future now has great prospects of paying off. "We wondered if one day pigs would fly. Well, now pigs are flying. I am very excited by the results," Ryder says.

    The impetus for the article is work that has induced pluripotent stem cells from skin samples held by the zoo. Of course they're talking about the potential for cloning whole animals, which with a sample of more than 8000 individuals from many species is quite something. It would be worth archiving many more samples from wild individuals -- even fecal samples might be sufficient in the future.

    Tags: 
    extinction
    biotech
    conservation
    cloning

  • Adopt a Neandertal

    Fri, 2010-07-23 16:34 -- John Hawks

    Kyle Munkittrick of the "Science Not Fiction" blog argues, "Yes, we should clone Neanderthals."

    A full response to this clearly deserves more thought than I can give right now. I'm going to keep pointing to arguments about the cloning issue, as I have done in the past with respect to human cloning.

    I'm completely in favor of cloning Neandertal tissue cultures. I really think we can learn a lot about our biology by understanding that part of our evolutionary history at a cellular level, and that knowledge may well help people.

    But making a whole person is different. Not only in an ethical sense but also a practical one, as our ability to understand the brain and immune system in living people isn't mature enough to make meaningful predictions about the small genetic differences between Neandertals and living people.

    Of course today this is all just idle talk. Someone who's talking about other extinct species, I don't take very seriously. We're talking about an ancient population of humans here. Not like quaggas; more like Tasmanians -- a group of people whose culture hasn't survived, and yet still has many living descendants. This shouldn't be a conversation about cloning, it should be about the logical consequence: adoption. Who will step up to adopt a Neandertal child, and why aren't they helping living children instead?

    Tags: 
    biotech
    ethics
    Neandertals
    cloning
    Neandertal DNA

  • Breaking legs for science

    Wed, 2009-07-08 12:06 -- John Hawks

    William Saletan tells the story of a woman who didn't like being 5 foot 1 inches tall, so she went to Russia to have her legs broken and stretched for 6 months. Just one of many examples of extreme body alterations that have become more common lately:

    Ban doesn't pretend her rationale was more than cosmetic. "A lot of young women feel insecure about their weight or their nose or their figure in general. Mine was my height," she told the Daily Mail. To Reuters, she added, "This is no different to having breast augmentation or nose procedures." To AFP, she underscored the social pressure behind such surgeries: "A lot of women, just through the way that society is and the pressure that we have, have insecurity and have some self-doubt."

    I wonder every so often who will jump first when genetic techniques become feasible to alter human biology. And then I remember the extremes of cosmetic surgery -- people sign up willingly, spending enormous sums and taking themselves away from their everyday lives for months, sometimes techniques that have very little objective impact on appearance.

    I suppose I should just sigh and be glad there are so many willing guinea pigs for new surgical techniques. But I'm apprehensive about the herky-jerky pace of progress -- fueled by anecdote-spreading networks of celebrities and idle rich people. Improvements in fertility treatments have largely occurred by this pathway, so there's a very real prospect that other genetic techniques will as well.

    Tags: 
    cloning
    biotech

  • Neandertal: The Resurrection

    Sun, 2009-02-15 23:58 -- John Hawks

    Friday morning, I got back to teaching after my trip this week. So I filled my students in a bit about the Neandertal genome. One of them had been reading the news, and noticed several stories seemed to obsess over the chance that Neandertals would someday be cloned.

    So she asked, "Is that something that you anthropologists sit around talking about?"

    Well, naturally I couldn't give away any professional secrets....but in this case I can honestly say I've never sat at the meetings, even after several beers, and discussed cloning Neandertals with other anthropologists.

    Not unexpectedly, this led to a short but animated class discussion about the ethics of Neandertal resurrection. I pointed out that some people are morally opposed to mammoth cloning, on the logic that we have to provide a full habitat for them, rewilding the American prairie. And even more think it unethical to bring a Neandertal baby into the world -- even disregarding the current inefficiencies of cloning. But some students found that thoroughly unconvincing.

    One who was unconcerned by the plight of the Neandertal baby nevertheless thought that the necessary mixture of Neandertal genes and human (or chimpanzee) oocytes was an ethical problem.

    Meanwhile, apparently just at the time I was discussing this little ethical conundrum in class, John Tierney was posting about it (Why Not Bring a Neanderthal to Life?). Well, why not indeed?

    But I’m afraid I can’t see the problem. If we discovered a small band of Neanderthals hidden somewhere, we’d do everything to keep them alive, just as we try to keep alive so many other endangered populations of humans and animals — including man-biting mosquitoes and man-eating polar bears. We’ve also spent lots of money reintroducing animals into ecosystems from which they had vanished. Shouldn’t be at least as solicitous to our fellow hominids?

    ... If our species disappeared and a smarter species took over the planet, I’d take the offer to be resurrected just on the theory that being alive beats being dead.

    Naturally, that drew a whole lot of comments -- many inane, but some give an interesting cross-section of peoples' base assumptions about Neandertals. In response to Tierney's last question, the first commenter wrote:

    Sure, I would too. But would you choose to have this smarter species create a virtual great-grandchild, who you would never meet or interact with, who you would have no opportunity to pass on any knowledge or wisdom or kinship to, who would live a life essentially as lab animal and historical exhibit? I would not.

    One was more sanguine:

    Yet, the hunger gatherer culture [sic] of the humans we label Neanderthal is truly dead –not hidden in genes. We will find out once we bring them back that Neanderthal will fully enjoy sitcoms, buy T shirts, and go shopping. In fact, with their bigger musculature and bigger brains, they are sure to find many a willing partner in match.com.

    From one who doubts that Neandertals are internet dating material:

    Mr. Tierney, if you knew with 100-percent certainty — before conception — that a pregnancy would lead to a severely mentally challenged human, would you think it “nifty” and a “gift” to bring to life such a hypothetical child? I see no difference between your proposal and giving a deliberate lobotomy to a newborn.

    I won't carry this on any further, but I find the exercise revealing. Some respondents want to bring them back to be lab animals for pharmaceutical testing, others think they will have as-yet-unknown powers. A few suggest that Neandertals are walking around us now; others think that we'd better be ready for female Neandertals that go into heat.

    My favorite, spinning off the "Dame Edna" high-pitched Neandertal voice idea, suggests that we may find a new Steve Perry.

    Tierney and others have given the price of Neandertal cloning as $30 million. As far as I can tell, that's just a wild-ass guess. But since I happen to be looking at a Geico ad right now, I would say that the price has to drop before there's likely to be a corporate sponsor. How about $6 million?

    I will say one thing, in all seriousness. Someday not too far from now, we will have the technology to add genes to chromosomes in human embryos, or to generate human embryos with artificially constructed chromosomes. On that day, the Neandertal genome will already be published and freely available. And there will be nothing to stop someone from generating an embryo with as high a fraction of Neandertal genes as desired.

    I can easily imagine the Abraham Lincoln genome, or the Mozart genome, or the Einstein being published. Once they are published, what would stop potential mothers from birthing baby Einsteins, or baby Lincolns?

    Is it really such a stretch from a baby Lincoln to a Neanderbaby?

    Tags: 
    biotech
    ethics
    Neandertals
    cloning
    Neandertal DNA

  • A problem with chimerical cloning

    Tue, 2009-02-03 12:08 -- John Hawks

    If your goal is to make cross-species hybrids, there is this problem to contend with:

    NEW YORK (AP) — It may be futile to try producing stem cells by putting human DNA into cow or rabbit eggs and making hybrid cloned embryos, a strategy that triggered controversy recently in Britain, a new study says. The animal eggs don't reprogram human DNA in the right way to generate stem cells, researchers report.

    "Instead of turning on the right genes, it turns out the animal eggs actually turn them off," said senior study author Dr. Robert Lanza of Advanced Cell Technology in Worcester, Mass.

    Cows and rabbits are pretty far off -- 140 million years or so of evolutionary separation might well have changed gene regulation in early embryogenesis so that the chemical signals in a donor egg wouldn't work with a human genome. Other hominoids would be less likely to generate problems. Of course, egg cells from rabbits are easier to come by than egg cells from gorillas.

    I'm more interested in the far-off possibility of cloning an extinct hominid. Would a Neandertal genome in a human egg lead to similar incompatibilities?

    There are a few lines of argument against it. For one thing, the combination of paternal and maternal genetic material in fertilized eggs doesn't tend to generate such incompatibilities between closely related mammals. The very fact that we see interspecific hybrids is a clue that the mechanisms of early embryogenesis are conservative, with few changes that would interrupt development.

    A complementary argument is that different groups of people living today are distantly related enough to have seen some such incompatibilities, if they were likely to happen. People in the world today are, on average, more alike than any living human and a Neandertal. But the total range of mutational variation today exceeds the average human-Neandertal difference for any given gene.

    On the other hand, there are reproductive incompatibilities today between some individuals within populations. And we don't know whether interfertility is identical between every pair of populations. We often assume this, but who has carried out the experiment?

    In any event, some kinds of genetic transfer will not work without being able to design custom cells. An egg cell that is not just taken out of a donor species, but is built to contain a specific array of signals, might avoid the problems with regulatory incompatibilities. Or it would give entirely new opportunities for epigenetic modification of genetic information.

    Tags: 
    biotech
    Neandertal DNA
    cloning

  • Cloning the extinct

    Sun, 2009-02-01 19:12 -- John Hawks

    Spanish scientists have cloned an extinct Pyrenean ibex:

    Using techniques similar to those used to clone Dolly the sheep, known as nuclear transfer, the researchers were able to transplant DNA from the tissue into eggs taken from domestic goats to create 439 embryos, of which 57 were implanted into surrogate females.

    Just seven of the embryos resulted in pregnancies and only one of the goats finally gave birth to a female bucardo, which died a seven minutes later due to breathing difficulties, perhaps due to flaws in the DNA used to create the clone.

    That's a pretty poor percentage. I tend to think such results from old frozen tissue aren't surprising. They'll do better when they have a better ability to repair tiny DNA defects. Or just to synthesize chromosomes from scratch.

    I'm fascinated by the successive removal of links between parent and offspring that genetic technology allows. First, with an endangered or extinct population, a parent and its captive offspring do not share ecology or natural history. Then, with artificial insemination, father and offspring do not share a relation with the mother. A clone need not even share protoplasm with its mother; although it is its "mother's" (or "father's") identical twin. With synthetic chromosomes, the only link is information.

    Tags: 
    biotech
    extinction
    cloning

  • Bringing back the overkill

    Sat, 2009-01-10 23:23 -- John Hawks

    New Scientist has a primer on extinct animals that might be candidates for resurrection by cloning. My preference is the short-faced bear:

    This towering beast would dwarf the world's largest living land carnivore, the polar bear. The short-faced bear may have been a third taller than the polar bear when standing upright, and it weighed up to a tonne. Recovering its DNA should be possible as there are specimens encased in permafrost. The short-faced's closest living relative is the spectacled bear of South America. The two species parted evolutionary company only around 5 million years ago, but unfortunately, at just a tenth the body mass of the short-faced bear, the spectacled bear is unlikely to be a particularly good surrogate.

    Or, OH OH, the giant beaver:

    There is fierce controversy over the reintroduction of normal beavers in some countries, so imagine how much fuss there would be over the reintroduction of the 2.5-metre-long giant beaver to North America. It's not too much to hope for a genome sequence of this massive rodent, says Hendrik Poinar, a geneticist at McMaster University in Hamilton, Canada. The capybara, which is about half the mass, would probably be the most suitable surrogate, though it might still be too distant a relative.

    It's too bad Paleocaster is too old -- their spiral burrows ("devil's corkscrews") are totally cool.

    The article ends on the depressing note that the first resurrected species will likely be one that is now living -- gorillas are the example mentioned. Since the cloning of the gaur, that scenario seems pretty likely.

    Tags: 
    megafauna
    cloning
    resurrection
    biotech

  • "With clones, what good does similar do?"

    Fri, 2009-01-02 16:57 -- John Hawks

    Eric Konigsberg writes a long story in the NY Times with quirky stories about the joy or disenchantment with the results of pet cloning:

    When Mr. Hawthorne recalls Missy, he tends to wax eugenic. “She was an amazing dog: superior intellect, incredibly beautiful, obedient, a phenomenal temperament,” he said. “I especially loved her majestic plume of a tail.” And in the clones, as he put it matter-of-factly, “all those qualities are represented.”

    People who sell cloning services have a strong interest in portraying the clones as identical to the original pets. After all, if people just wanted a similar pet, they could get another pet of the same breed. For a price in the neighborhood of a Maserati, these buyers are looking for something a little more particular -- if not their dead pet reborn, at least a facsimile.

    Or a science fair project for their grandkids:

    Last spring, Skye completed a science project, “Cloning Grandma’s Dog” that included a behavioral comparison chart. Among other findings, the study concluded that Mira shares Missy’s fondness for broccoli and “lots of snuggles” — both dogs scored five out of five points in these categories, in addition to the one for “likes long walks.” (“Most dogs do,” Skye noted under “comments.”) Two key matters of variance were “Jumps into cars” (“Clone still learning which car is ours”) and “Hates camera flash” (“Clone did not respond to standard flash”).

    The story at the end of the article, about the proud first owners of a cloned dog from this particular company, is creepy:

    “Breathe, breathe,” Mr. Hawthorne said. “How does he look?”

    “He looks like Neanderthal Man,” Mr. Otto called out from the background.

    “No, he doesn’t,” his wife said.

    “I can’t say he looks exactly like our other one,” Mr. Otto shouted.

    “Yes, he does,” his wife said.

    Oh, yes he does. This is reminding me of the BBC show that investigated people who adopted "real baby" dolls. Weird.

    Tags: 
    cloning
    biotech
    social

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Neandertals

For years, I've worked on their bones. Now I'm working on their genes. Read more about the science studying these ancient people.

Denisova

From a finger bone of an ancient human came the record of a completely unexpected population. My lab is working on the science of the Denisova genome.

Acceleration

The advent of agriculture caused natural selection to speed up greatly in humans. We're uncovering some of the ways that populations have rapidly changed during the last 10,000 years.

Malapa

Just outside Johannesburg, the Malapa site is producing some of the most exciting finds in human evolution. This site is the headquarters of the Malapa Soft Tissue Project.