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Blending Mice and Men

An anonymous reader sends in this piece about chimeras - not the ones with a THAC0 of 11, but a more general term meaning any multi-creature hybrid. A comprehensive look at the moral and scientific issues surrounding this area of biotech.

8 of 387 comments (clear)

  1. They've been around for a while... by ssand · · Score: 5, Interesting

    The latest Chimera's discovered can be found here on worth 1000. Behold what science can do now!

  2. This is how society blends mince and men... by ReeprFlame · · Score: 5, Funny

    The only way I see blending of mice and men is when our hands are merged with our mice when gaming 24/7 on the hot new RPGs!

  3. See what's gonna happen... by cy_a253 · · Score: 5, Funny
    Now Weissman says he is thinking about making chimeric mice whose brains are 100 percent human.

    Wow. A super intelligent mouse. Aren't they afraid that mouse will then get a slow-witted sidekick and try to take over the world?

  4. Re:THAC0? by Romothecus · · Score: 5, Informative

    Actually, your post is only half correct. THAC0 is analagous to what is now called attack bonus; THAC0 stood for "To Hit Armor Class 0." Armor Class was still armor class, however, a lower armor class was better and 0 was considered the best non-magical AC (a human wearing full plate had a AC of 0, as I recall.)

  5. Buffalo Wings... by ParadoxicalPostulate · · Score: 5, Funny

    Maybe now they can actually serve real buffalo wings at Pizza Hut.

  6. Re:it's a new age by Planesdragon · · Score: 5, Interesting

    Hopefully, atleast this will make people realize that animals should be given much the same right as humans

    "An animal may have rights when it asks for them."

    This may be a parahrased quote from a Supreme Court judge. If not, it's one that I'll wager they would agree with.

    When your ape signs "please let me vote for president, I care about ecological progress" as interepted by someone without bias, and it can then sign "yes, I swear and understand" in court, it'll be able to win rights in a rather simple court.

    But they can't. And so they don't have equal rights to humans.

    OTOH, it's entirely civilized to kill humans. It's all about WHEN and WHY that defines civlization, not the actual killing or lack thereof.

  7. They've been around 3 billion years or so by jd · · Score: 5, Interesting
    As soon as you get multicellular life - even just two cells - you have the possibility of chimeras. It's actually more than possible, it's a very high probability.


    Ok, maybe they're not chimeras in the sense of two radically different lifeforms, but the article considered a mother carrying DNA in their blood from their child as being close enough, so I think it's OK to consider any lifeform in which there are two or more non-identical DNA sequences present.


    DNA is horribly unstable stuff. That's why mutations occur. It's also why certain cancers occur. All it takes is for a cell's DNA to be altered. A bad copy, a reaction with a free radical, whatever. What you get is a cell with different DNA than other cells.


    99% of the time, that's not a problem. The cell destroys itself or gets destroyed by the body's defenses. No big deal. Some of the remaining time, the cell goes cancerous. Either the cancer or the organism is destroyed.


    Most of the remaining incidents would likely be chimeras of a kind, especially if the organism is still developing. There's absolutely nothing to stop a cell mutating subtly and then copying that mutation into every copy of that cell ever made. If it's a useful mutation (it can survive and it confers an advantage) AND it occurs early enough in life that descendents acquire that mutation, we call it evolution. But I can think of absolutely no reason why a useful mutation cannot occur at any time in an organism's lifetime. It's just going to be rather more regional and it probably wouldn't be conferred to descendents.


    Although much less likely than a single cell mutating, I can see absolutely no reason why it would be impossible for multiple cells to mutate in a way that would (a) individually function and (b) function together as a single organism.


    Exposed to an environment that is sufficiently hostile to DNA, there is a non-zero probability of just about any imaginable set of mutations occuring. This creates an interesting philosophical problem. There's a lot of debate as to when human life begins. But by the arguments given above, there is a non-zero probability that any life could be human, and a (much higher) probability that any human is not entirely human.


    If cells can mutate, blend, fuse, do whatever cells like doing on weekends, etc, then is it meaningful to consider how human a chimera is? We must all be chimeras. It's just a matter of degree.


    "Human" cannot, then, be the state of an organism, because no organism is guaranteed a uniform state, unless it's unicellular. At best, it can only be a composite of states. However, that might not be good enough, either. Let's take the most extreme example possible - some idiot decides to blend humans and chimpanzees - not through breeding, but through genetic and chimeric techniques.


    Now what happens? The cells will very likely fuse extremely well, being far more similar in nature than the pig/human example in the article. Let's say that the result is a "perfect" 50/50 mix. Are they human or not? Would it be possible to tell, without careful DNA analysis?


    Ok, now let's say that the ratio is 90% human and that it turns out most people accept the person is human. Fine. Let's also say that, as a result of normal cell mutations (as outlined above) and/or cell replacement the ratio falls over the lifetime to below 50% human. Are they still a person?


    Or take the reverse scenario. They start off 90% chimp, and (through cell mutations/replacement) become over 50% human. In other words, can you "become" human after you're born?


    It seems to me that the entire problem is very complex and that existing definitions of what an organism is simply aren't good enough to classify organisms that are non-trivially chimeric.

    --
    It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
    1. Re:They've been around 3 billion years or so by shawb · · Score: 5, Informative

      And then there's the whole issue of mitochondria/chlorplasts. Those were originally single celled organisms that got absorbed by another single cell organism, but then reproduced rather than being consumed.

      The resulting Chimera passes down both the "host" organism plus the mitochondria/chloroplasts with their own unique DNA from the cell proper.

      End result: Now these two once foreign cells are essentially the powerhouse of modern life. Chloroplasts are where plants actually convert light energy into chemical energy (stored as sugar) and mitochondria are where plants and animals (and most other assorted organisms as well) then convert sugars into readilly available energy, ATP (Adenosine TriPhosphate.)

      --
      I'll never make that mistake again, reading the experts' opinions. - Feynman