All Animals Are Equal:
(Part I)

General Bioethics — By on July 25, 2005 at 2:24 am

As a species, we homo sapiens are remarkably self-centered and ungrateful. Our monkey ancestors spent millennia mutating and surviving in order that we might reach the top of the food chain. Yet having reached the pinnacle of the evolutionary ladder how do we show our appreciation? By snubbing our primate forebears and treating them as if they were mere animals.
Take, for example, the reaction to cutting-edge experiments in which scientists inject human brain cells into monkey fetuses in order to study the effects. The critics of such procedures argue that if these fetuses are allowed to develop into self-aware subjects that science will be thrown into an ‘



  • http://www.sufficientscruples.com Kevin T. Keith

    How then do we justify experimenting on such creatures? Without a significant basis in either genetics or characteristics, what grounds do we have for not including these animals under the

  • http://thebronxblogger.blogspot.com Matthew Goggins

    Kevin Keith,
    Excellent comment.
    Question: If you had to choose between rescuing the life of a good dog, and rescuing the life of a person you knew to be evil and noxious, whose life would you save?

  • Ken

    Some months ago, I came across Professor Tolkien’s famous essay “On Fairy Stories”.
    In one of the footnotes at the end of the essay, he notes a change in idea from “man is an animal” (which has a long tradition) to “man is ONLY an animal” (which leads to the subject of this posting).
    I call the footnote “Tolkien vs PETA”.

  • http://alangrey.blogspot.com Alan Grey

    Joe,
    Please note that the 98%+ genetic similarity between chimps and humans is outdated (and poor) science.
    The current figure (britten) is more like 95%, and even that may be too high. Tatsuya found it was more like 86.7%
    Of course, scientists for years have said that it was a ‘fact’ that there was 98%+ similarity. They can’t even get that right.
    References
    http://news.nationalgeographic.com/news/2002/09/0924_020924_dnachimp.html
    Britten, R.J. 2002.

  • http://blogotional.blogspot.com/2005/07/chimeras-serious-look.html Blogotional

    Chimeras – A Serious Look

    People who argue for radical equality in any field disregard that such efforts do not raise up the lowly without also knocking down the high.

  • http://blogotional.blogspot.com/2005/07/chimeras-serious-look.html Blogotional

    Chimeras – A Serious Look

    People who argue for radical equality in any field disregard that such efforts do not raise up the lowly without also knocking down the high.

  • Nick

    Alan:
    Of course, scientists for years have said that it was a ‘fact’ that there was 98%+ similarity. They can’t even get that right.
    Short response: The smug tone of your comment gives no indication that you actually understand the studies that you are citing. Which scientists got it wrong, how specifically did they get it wrong, and what makes you so sure that the new scientists got it right?
    Long response:
    1. What scientists have said for years is that DNA-DNA hybridization studies suggest a human-chimp genome similarity of ~97-98%.
    Incidentally, RJ Britten (who you cite above) and his colleague DE Kohne developed the earlier DNA-DNA hybridization technique. So, in your opinion, is Britten a clumsy researcher who “can’t even get that right” or a good researcher who should be cited for the accurate percentage?
    2. Anzai et al. and Britten’s new analyses were restricted to small regions of the genome, while DNA-DNA hybridization estimates similarity across the entire genome.
    3. Anzai et al. and Britten’s new measurements are fundamentally different than the earlier DNA-DNA hybridization, because they include insertions and deletions. Insertions and deletions cannot be measured by DNA-DNA hybridization, because, obviously, you cannot hybridize DNA from two species if that segment is absent from one of the species.
    Note that Anzai et al’s analysis of the sequence that is present in both species gives a percent nucleotide identity of 98.6%. Britten also got a percent nuceotide identity of 98.6% for sequence present in both species. Analysis of the sequence that is present in both species is directly comparable to the earlier hybridization studies. Significantly, it gives essentially the same result, indicating that the hybridization studies were accurate within the limitations of the experimental design.
    4. Anzai et al.’s comparison indicates that in coding sequence of genes, the average human-chimp similarity is 98.9%, again comparable to the old DNA-DNA hybridization studies.
    5. Anzai et al. indicate that the majority of the insertions and deletions consist of mobile genetic elements (retroviruses, transposons, etc). What function, if any, they have remains an open question. However, note that the available genetic data suggests that most these types of repetitive elements have no function, and the functions that been proposed for some are intimately related to evolution. Although IDers like to claim that all repetitive DNA is functional, they haven’t actually tested for any specific functions and rarely even propose functions.
    If the major functional differences between humans and chimps do turn out to be insertions and deletions, this is good news for evolutionary biologists. The mutational mechanisms by which insertions and deletions occur are fairly well understood (Britten mentions a few in his paper), and they would directly contradict creationist and ID claims that mutation cannot increase the information content of the genome.
    6. So to conclude, the old estimate of human-chimp DNA similarity is not obviously poor science, as you claim. Rather, it is an estimate based on a particular technique. Other techniques give slightly different estimates, but all are broadly consistent. What the significance of that nucleotide similarity is to the phenotypic differences between humans and chimpanzees will be worked out by geneticists, not the internet snipers who enjoy mocking them.

  • http://sheepcrib.blogspot.com/2005/07/kingdom-blogs-around-sphere-today-726.html The Sheep’s Crib

    KINGDOM BLOGS – Around the Sphere Today! (7/26)

    A periodic post of things I’ve read and like in the Kingdom part of the blogosphere …

  • http://alangrey.blogspot.com Alan Grey

    Nick,
    For nearly 30 years, scientists have been talking about a 98%ish similarity. Why should I bother specifying who and when? Almost every person you come across, Joe included, cites this figure as truth. It is now an urban legend on par with the idea that we only use 10% of our brains.
    The latest figure has been around for several years, and we still see scientists quoting it.
    As to your question “what makes you so sure that the new scientists got it right?” I believe this falls into the category of experimental science, and so it is quite feasible, that in actually looking at the genetic sequences, you can actually tell the differences and repeat the observations.
    The 98% figure, based on a technique that was not verified (I.e. No check was used against 2 species full genomes to ensure that it provides an accurate figure) was treated as simple fact and repeated in paper after paper.
    All I have been trying to do here is
    1) correct the mistaken notion of 98% similarity
    2) Point out that a figure that has been widely promoted as fact was significantly wrong.
    You seem to want to go more in depth into the topic, which is fine. But understand, that was not the purpose of my comments.
    “3. Anzai et al. and Britten’s new measurements are fundamentally different than the earlier DNA-DNA hybridization, because they include insertions and deletions.” Of course. The original technique was flawed and incomplete.
    “5. Anzai et al. indicate that the majority of the insertions and deletions consist of mobile genetic elements (retroviruses, transposons, etc). What function, if any, they have remains an open question. However, note that the available genetic data suggests that most these types of repetitive elements have no function, and the functions that been proposed for some are intimately related to evolution”
    Sorry Nick, but the functionality of these non-coding regions is becoming more and more documented. You need to keep up with the science more. Most of these sequences are important for embryological development, gene regulation etc. If you bothered to keep up, you would even know about this article
    http://www.nimh.nih.gov/press/microsatellites.cfm
    The article talks about how these regions you say have ‘no function’ are vital for social behaviour
    or this article
    http://sciencenow.sciencemag.org/cgi/content/full/2005/714/4
    (You need to have a subscription to this one) which talks of the funciton of ‘Junk’ DNA
    or this article
    Woolfe et al.,

  • Nick

    Alan:
    For nearly 30 years, scientists have been talking about a 98%ish similarity. Why should I bother specifying who and when?
    Because, when I actually look at the scientific literature, I see either a) the figure given as an estimate or b) citation to the actual experiments so that readers can see how it was generate. I doubt your assertion that scientists have frequently published it as an unqualified fact.
    The 98% figure, based on a technique that was not verified (I.e. No check was used against 2 species full genomes to ensure that it provides an accurate figure) was treated as simple fact and repeated in paper after paper.
    When the hybridization experiments were performed, direct sequence comparison of the two complete genomes was not possible. However, the hybridization technique looks at a larger portion of the genome than the two sequence papers that you cited. In fact, Anzai et al chose to look at the MHC region, because they expected that was a region important for human-chimp differences. Therefore, it is even less clear that their estimates are valid for the entire genome.
    All I have been trying to do here is
    1) correct the mistaken notion of 98% similarity
    2) Point out that a figure that has been widely promoted as fact was significantly wrong.

    It is 2) that I am mainly concerned with. You have asserted that scientists published the percentage as “simple fact” rather than an estimate and have smugly noted that “they can’t even get that right.” Back up your claim.
    Sorry Nick, but the functionality of these non-coding regions is becoming more and more documented. You need to keep up with the science more. Most of these sequences are important for embryological development, gene regulation etc.
    Most of the sequences? You are simply wrong, and your claim is easily disposed of:
    1. It is known that phenotypic complexity does not correlate with genome size. Zebrafish and pufferfish are equally complex organisms, but zebrafish have genomes four times larger than pufferfish. The reason? Pufferfish lack the huge amounts of repetitive DNA in the zebrafish. If that repetitive DNA were necessary for making a fish, there should be no puffers.
    2. Some amoebas have genomes 200 times larger than the human genome (human genome 3.4 billion bp, Amoeba dubia 670 billion bp). What is all that extra DNA doing? It sure isn’t controlling social behavior in amoebas.
    3. Extremely large deletions can be made in non-coding DNA without disrupting development:
    Nobrega et al. (2004). Megabase deletions in gene deserts result in viable mice. Nature 431: 988-93.
    Most of the papers that you cited do not support your position:
    http://www.nimh.nih.gov/press/microsatellites.cfm
    This study by Hammock and Young looked at a single microsatellite in the vasopressin gene. There are many thousands in the genome. The authors do not claim that they have discovered a general function of all or most microsatellites. At most, they speculate that similar functions may be associated with some of the microsatellites that are located within the promoters of other genes. This would be a tiny subset of all microsatellites. The authors also point out that this study provides a mechanism for the evolution of changes in social behavior, because change in microsatellite length is a well known, simple mechanism.
    This paper is consistent with my prior claim that most repetitive sequences are nonfunctional, but some have functions intimately involved in evolution.
    http://sciencenow.sciencemag.org/cgi/content/full/2005/714/4
    (You need to have a subscription to this one) which talks of the funciton of ‘Junk’ DNA
    or this article
    Woolfe et al.,

  • http://alangrey.blogspot.com Alan Grey

    I have been away on holidays for the last few days. I will respond to this soon.

  • http://alangrey.blogspot.com Alan Grey

    Sorry for the long comments Joe.
    Nick (Your comments in italics, my previous are in bold)
    Alan:
    For nearly 30 years, scientists have been talking about a 98%ish similarity. Why should I bother specifying who and when?
    Because, when I actually look at the scientific literature, I see either a) the figure given as an estimate or b) citation to the actual experiments so that readers can see how it was generate. I doubt your assertion that scientists have frequently published it as an unqualified fact.
    I guess that is because you have been reading too much talk.origins and not actually doing your own research