Defining an Organism

zygote.pngIn a previous discussion on embryonic stem cells, dlw asserted the following definition of an organism from Merriam Webster and the subsequent assertion:

1 : a complex structure of interdependent and subordinate elements whose relations and properties are largely determined by their function in the whole
2 : an individual constituted to carry on the activities of life by means of organs separate in function but mutually dependent : a living being

"Thus, because it is not until the fifth week that we see organogenesis begin, according to scientific research, we cannot technically call the newlyformed zygote an organism, unless you want to use a nonscientific standard def'n of organism."

The Merriam Webster definition looks acceptable, but dlw misreads it. Two definitions are proposed, but they are not both necessary for an organism. A bacterium has no organs, but is composed of plasmids, ribosomes and sundry superstructures that are guided by whole. If a bacterium, the smallest living thing, is not an organism, I'm at a loss as to what is. The same can be said for an unicellular entity, like a zygote, that was not originally part of some tissue.

A skin cell or brain cell is composed of many parts whose functions are dictated by the whole cell (at least in part) as well, but they are not organisms. A skin or brain cell has features that make very little sense if the cell is taken on its own. What good is a synapse or a dendrite on a neuron if it's not plugged into a network, for instance? If you isolate a beta cell from a Isle of Langerhan in the pancreas–whooppee–it can make insulin, but what good is that without downstream cells to receive the message?

One may counter: fine, but how long would a zygote last without the womb, or an embryo without a placental life-support system? These are reasonable counterexamples, though I do not think they are on the same plane as an isolated brain or pancreatic cell like I mentioned above.

An organism may be dependent on another organism for sustenance but may still be distinct–for instance, an E. coli bacterium need human beings, specifically our large bowel, but we can distinguish between our two respective species. A newborn human may be out of the womb, but is quite dependent on other humans for support; yet we'd still mark the newborn as being a distinctive organism.

A person may be hooked up to life-supports machines–and in the future, these machines may even be organic or alive themselves–yet I think the physicians and the patient would have little trouble distinguishing between the two on a conceptual level, even though (depending on the nature of the device(s)), the two may become rather entwined.

One may argue that a hospitalized person lived on his own before extrinsic machinery came to his aid. True, but a fertilized zygote lives on his or her own before implanting in the uterine wall and cooperating with the maternal tissues to form the placenta. There is a distinction between the two. Thus a zygote may be defined as an organism. The link I provided implicitly assumes that the organism starts as a zygote. I'd be very curious to see a serious (i.e., peer-reviewed) biological article try to overthrow that, if a reader could provide one.

The link above is to a free online version of the Molecular Biology of the Cell, which is the standard text on cell biology, and which I personally recommend as an excellent text. The questions at the end of every chapter focus not just on memorization (which is necessary), but also on problem solving skills, and having you think through how experiments (including some very important historical ones) should be designed.

Addendum 12/10/05: Wesley J. Smith points to an interview about "the fact that so many scientists feel that if they come out against cloning they will be branded anti-science and face professional repercussions". It includes a definition of "organism".

Comments 18

  1. Steve Nicoloso wrote:

    Truce. Fine. I’ll have you know that a majority of the people I work with have PhDs, and the pattern (of incompetence in matters unrelated to narrowly selected fields) holds far more often than it should. In the interests of full disclosure, I’ll admit that I do not hold a PhD, having chosen to follow the wicked wiles of filthy lucre, rather than the wicked wiles of filthy philosophizing.

    😉

    Posted 08 Dec 2005 at 3:36 pm
  2. Steve Nicoloso wrote:

    Jerry, thank you for this.

    I had it out with David on this exact subject about a year ago over at his blog. You can read the grueling exchange here. (I post as “Anonymous” but “sign” my real name in the posts.) Therein David variously tries (if memory serves) a two-fold muddle:

    1) if the newly formed zygote is an organism, then so is any particular adult cell (WTF?);

    2) the newly formed zygote cannot be an organism because it doesn’t have organs (WTF?!??!!!!).

    The idea that a human zygote is not a unique human organism is absurd on the face of it, and doesn’t even deserve the fine fisking you give it here. All I can say is that it is terribly sad that we’ve come to a day where, when having met someone with a PhD, we are forced to ask: What was it in? Having a PhD used to mean something about a person’s broader, general capabilities. But no more. Today a PhD in political economy might very well mean you possess the biological insight of a 4 year-old… only the PhD makes you MUCH more dangerous.

    Posted 07 Dec 2005 at 6:01 pm
  3. Stuff wrote:

    Jerry and Steve, you know I’m with you both. :)

    Posted 07 Dec 2005 at 8:33 pm
  4. John wrote:

    Firstly, where did the lambasting of PhD’s come from?

    Also, I think the Websters definition is drawing a distinction between a complex organism and single cell creatures. So by that definition E Coli is not an organism. It is alive, but is a simpler form of life than an organism.
    I don’t really think that the distinction has any relevency to the abortion debate (which I feel is what we’re really talking about here) but it is a valid distinction to make.

    Posted 07 Dec 2005 at 11:56 pm
  5. Steve Nicoloso wrote:

    John, the lambasting of PhDs comes from the fact that one of the disputing parties in question has a PhD… unfortunately to no avail.

    Obviously a bacterium is an organism, in the (Webster’s admitted I think) sense of a living thing. And if Webster’s doesn’t agree, then the problem is with Webster’s, not the bacterium. I will admit there is murky ground about prions and perhaps viruses. But a bacteria is categorically alive and therefore categorically an organism.

    The distinction would have little indeed to do with the abortion debate if it weren’t for certain people making the outrageous claim that a newly formed human zygote is not, biologically speaking, a human organism.

    Posted 08 Dec 2005 at 12:56 am
  6. John wrote:

    I was citing the progression of
    cell-tissue-organ-organ system-organism.

    Which would have a bacteria as a cell, skin as a tissue, a pancreas as an organ, a jellyfish as an organ system and a cheetah as an organism.

    Posted 08 Dec 2005 at 1:43 am
  7. Jerry Nora wrote:

    John, you might have that, but biology doesn’t. Please follow that link I included. If you can find me stuff in the biological literature (or even philosophy of biology lit.) that makes a good case otherwise, I’d like to see it, but it ain’t in the cards as I see it from the science.

    Posted 08 Dec 2005 at 2:57 am
  8. Jerry Nora wrote:

    Maybe we should also agree to a truce to no longer discuss the merits of PhDs, though I reckon dlw may be emailing Steve about those words in the future!

    Posted 08 Dec 2005 at 3:02 am
  9. gbm3 wrote:

    Has anyone heard of the “active” vs. “passive” potential argument for zygote personhood?

    See (among others)

    http://www.imago-dei.net/imago_dei/2005/08/the_potential_p.html

    Posted 08 Dec 2005 at 7:48 pm
  10. Jerry Nora wrote:

    Yes, I have; the argument stems from Aristotle (the Physics, I believe…).

    I’d want to hold off on personhood for now. If we cannot even agree that a zygote is an organism (and if not, what is it?), personhood debates will be rather unproductive…There’s more than enough grist for our mills right now!

    This could make for a good independent post, gbm.

    Posted 09 Dec 2005 at 3:01 am
  11. gbm3 wrote:

    It would make a “good independent post”.

    I believe this active v. passive potential argument is relevant to the organism question. If the zygote is an individual person, it has to be an organism.

    But, as you say, we should probably hold off on this debate.

    Posted 09 Dec 2005 at 4:58 pm
  12. Jerry Nora wrote:

    Yes gbm, if the zygote is a person, it must be an organism, but a zygote may be an organism without being a person. Hard experience on this blog has taught me that without clearer up more fundamental criteria like whether something’s an organism, a debate on personhood will be groundless and just get people worked up for no good. :)

    Posted 10 Dec 2005 at 2:00 pm
  13. dlw wrote:

    Jerry, I was hoping more to hear back from you on my consequentialist musings wrt euthanasia.

    I’m disappointed. I think you’re a smart guy, but your arguments above are lame and the sort that mainly a not-so-critical polemicist without a PhD, who apparently thinks repeating his old-arguments with profanity will make them more persuasive, would tend to appreciate because they may not understand the linguistic games at issue. 😉

    I offer two def’ns of organism, lets call them sets orgA, orgB. In both cases, the newly-formed zygote, z, is not part of orgA or orgB. You bring up an example, x, that also is not part of orgA or orgB, but is part of orgC, a different set based on a definition you only allude to. You describe orgC by how a cell, c, is part of orgA and orgB, it is not part of orgC. You then bring up links to a biology textbook chapter and a blog-entry by a scientist that uses orgC and then put the burden on others to show that orgC is not a proper def’n of organism.

    The problem is that your def’n of organism is really the def’n of entity. 1 a : BEING, EXISTENCE; especially : independent, separate, or self-contained existence b : the existence of a thing as contrasted with its attributes
    2 : something that has separate and distinct existence and objective or conceptual reality.
    The other problem is that just because a study uses orgC, does not mean that there are not other studies that use orgA or orgB. In fact, it says absolutely nothing about which def’ns have more currency in scientific papers and if the point is to appeal to science to undergird the claim that the newlyformed zygote is a human organism, a much more rigorous statistical analysis of peer-reviewed biological texts would be in order.

    Otherwise, we’re stuck in a rhetorical tug-of-war between (orgA or orgB) vs orgC. As I recall, I did make an argument that, given the considerable linguistic ambiguity associated with the term organism, that it was improper to make bold statements about the newly-formed zygote being a human organism. As I understand it that argument still stands, despite your post above.

    dlw

    Posted 13 Dec 2005 at 5:59 am
  14. Steve Nicoloso wrote:

    Repeating my old arguments with profanity?! Actually, David, they are are your arguments and repeated with vulgarity not profanity (see the cursing post)… At any rate, I’m inclined to agree with Mark Twain that “Under certain circumstances, profanity provides a relief denied even to prayer”, especially when dealing with an argument so absurd.

    A living thing is an organism, categorically, as your own definition allows. Biologists study what? Life (hence the “bio-” bit). Microbiologists study what? Microbes, little single-celled living things. A bacterium is alive. Therefore a bacterium is an organism. A definition that ambiguates this or fails to get this is either a) a pretty bad definition; or b) profoundly misunderstood. (Here I suspect it is the second conclusion.)

    I’ll admit (and in fact I did up there somewhere) that there exists ambiguity in the definition of an organism when attempting to apply it to prions or viruses. But there is none, absolutely none, regarding bacteria, or alge, or fungi, or fertilized mammalian oocytes. This supposed “linguistic ambiguity” is purely illusory, merely an artifact of wish-fulfillment, so that you may somehow “move beyond” the abortion debate to stuff you really do give a damn about. Ergo, you come up with this theory (a really bad one–one that I haven’t even seen parroted by pro-aborts) that somehow makes non-icky abortions (e.g., caused by oral contraception, morning after, RU-486, and early D&Cs) morally okay: Well, you see, a zygote really isn’t an organism until the 5th week of gestation.

    How can one argue with someone who actually thinks this is an argument? It’s ludicrous. Oh, this is abuse, the argument is down the hall, room 12-D.

    I’ll say this: your ignorance is NOT invincible.

    Best regards

    Posted 13 Dec 2005 at 11:32 pm
  15. Jerry Nora wrote:

    “I’m disappointed. I think you’re a smart guy, but your arguments above are lame and the sort that mainly a not-so-critical polemicist without a PhD, who apparently thinks repeating his old-arguments with profanity will make them more persuasive, would tend to appreciate because they may not understand the linguistic games at issue.”

    Well, dlw, next time, feel free to cut this sort of editorial commenting out (for the same reason I told Steve to stop cutting on you–if you two must play this game during Advent, please don’t drag me into it!).

    But on to the real meat of the argument:

    “I offer two def’ns of organism, lets call them sets orgA, orgB. In both cases, the newly-formed zygote, z, is not part of orgA or orgB. You bring up an example, x, that also is not part of orgA or orgB, but is part of orgC, a different set based on a definition you only allude to. You describe orgC by how a cell, c, is part of orgA and orgB, it is not part of orgC.”

    No, I asserted that a zygote, like a bacterium, falls under the first defition you quoted from the dictionary–a complex structure where the parts are subordinted to the whol. How exactly do I throw in a new one?

    Regarding my textbook example, I wanted to emphasize that this idea of an organism is not just something we bandy out in bioethics, but has consequences for the study of biology itself. You emphasized the scientific basis of your assertion that a zygote is not an organism, and even said that to assert other would is impossible “…unless you want to use a nonscientific standard def’n of organism.” This is part of the block of text quoted in this entry, which I copied and pasted from the original comment.

    My aim was to show that scientists argue to the contrary, despite your own strong claim of scientific legitimacy, and asked if there was any peer-reviewed literature supporting your vision of the zygote. If there is not, I don’t think your claim of scientific justification is warranted.

    Posted 14 Dec 2005 at 1:49 am
  16. dlw wrote:

    my apologies to Jerry for my cursory and unthorough treatment of his post. I also want to apologize to Steve and Jerry and Funky and everyone else for my editorial trash-talking of Steve.

    Unfortunately, partially due to time-constraints, I’m afraid I only plan to respond to Jerry. I have not found Steve to be an enjoyable dialogue partner on this topic, in the past. My apologies.

    miracle of miracles, I discovered shortly after getting your email that I can post again comments here at Ales RArus.

    No, I asserted that a zygote, like a bacterium, falls under the first defition you quoted from the dictionary–a complex structure where the parts are subordinted to the whole. How exactly do I throw in a new one?

    Okay, my bad. So you are saying that, x, bacterium, is a part of orgA, though not orgB and the same may be said of z, whereas c is not part of orgA, even if it is part of orgB.

    I am at a disadvantage here, as I have not studied this part of biology for some time. I guess the crux of the matter comes down to whether the analogy is judged as valid by the greater scientific community. Does the newlyformed zygote have “plasmids, ribosomes” and what-not like the bacterium does?

    We own “From Conception to Birth” by Alexander Tsiaras in my household. On page 54, it describes how the morula shifts from a dense cluster of identical cells to form a single-layered hollow sphere around a fluid-filled cavity. That hardly sounds like an organism to me…

    Regarding my textbook example, I wanted to emphasize that this idea of an organism is not just something we bandy out in bioethics, but has
    consequences for the study of biology itself. You emphasized the
    scientific basis of your assertion that a zygote is not an organism,
    and even said that to assert other would is impossible “…unless you want to use a nonscientific standard def’n of organism.” This is part of the block of text quoted in this entry, which I copied and pasted from the original comment.

    I read the link and fail to see why the times that mice are referred to as organisms must also refer to them when they are undifferentiated embryonic stem cells. The word organism is used at the beginning and the end and is used to compare and contrast with other multicellular organisms.

    I think you’re argument based on it is a simple non sequitur.

    Although, I agree that there were subtleties to the def’n(s) of organism that I should have heeded more carefully before making such a bold statement earlier. I agree that the issue is not the presence of organs, per se, but the validity of the analogy you made.

    My aim was to show that scientists argue to the contrary, despite your own strong claim of scientific legitimacy, and asked if there was any peer-reviewed literature supporting your vision of the zygote. If there is not, I don’t think your claim of scientific justification is warranted.

    I disagree that the burden of proof is on me to disprove the analogy you made in the OP. The article you linked to doesn’t confirm it upon careful reading and the blog-entry you linked to doesn’t really count as a peer-reviewed article. God knows, people get away with saying all sorts of funky dung-oriented stuff at blogs. 😉

    I still think that a better case needs to be made before one can use the term organism to apply to the newly-formed zygote. Too many use it to easily, just like they may use the word “fact” too easily.

    dlw

    Posted 14 Dec 2005 at 4:50 am
  17. Steve Nicoloso wrote:

    Just to be sure we’re clear here, I’ve stopped “disussing” this particular point a year ago, for to me the only thing remaining to discuss is what penance might be required for your siding with the pro-aborts and betraying of the Author of Life and his Church. This is not (never was) an intellectual question. It is a moral one. All my remarks should thus be taken as simple scourging, that being the most charitable action (more so than neglect) that could be taken. In purgatory, David, should you make it that far, you’ll thank me!

    Cheers!

    Posted 14 Dec 2005 at 7:27 pm
  18. Steve Nicoloso wrote:

    From a review of A Jealous God

    [T]he book reveals that in a friend-of-the-court brief in Roe v. Wade, more than two hundred doctors from institutions like Harvard Medical School and the Mayo Clinic concluded that “modern obstetrics has discarded as unscientific the concept that the child in the womb is but tissue of the mother. [ ?] From conception the child is a complex, dynamic, rapidly growing organism.”

    Posted 16 Dec 2005 at 4:47 am

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