Thought on reproduction and the meaning of species

I was recently reading a short story by Samuel Delany, which included the statement

“The reproductive function, was it primary or adjunctive? If… you
consider the whole ecological balance a single organism, it’s adjunctive, a vital
reparative process along with sleeping and eating”

This has been bugging me somewhat ever since, and I believe I’m starting to get a handle on why.

We are in the habit of treating reproduction as the primary function of an organism; it’s a time-honored Darwinian argument, it fits with our models and understandings of natural selection and the like, and it’s seeped fairly thoroughly into even our political discourse — vide arguments that various behaviors are “unnatural” because they’re non-procreative.

However, there is a substantial problem with considering the reproductive function as primary: it implicitly is considering the species to be a natural division of life, and treating this function as its core repair and development mechanism. However, I suggest that this is a bad division to make.

Part of the problem can be thought of by considering cells – one does not speak of their “purpose” as being to reproduce themselves, but rather of their function within the body. We consider them (for the daily purposes of macro-biology) to be important because of their functions in the body as a whole, their transport of products, their structural effects, and so on, most of which happens far outside their reproductive cycle. When we consider them microbiologically, on the other hand, they make a very natural division; each cell can be thought of as a more or less monolithic object, interacting with the outside world but complete in its own right.

I suggest that the points at which we draw divisions and say “one of these things is a unique object” has to do with strengths of coupling. I say that two people are two separate organisms because the coupling between people is much less than the coupling between parts of the same person, by several orders of magnitude; thus animals make a good boundary point. Cells and mitochondria do as well. But not, I suggest, species.

The reason is that the inter-species coupling strength is equal to, or occasionally much greater than, the coupling strength between the individuals which make up said species. (As an example, consider the effect of removing one’s children versus the effect of removing one’s gastrointestinal flora – or any other organism with which one has any strong connection, as predator, prey, parasite or symbiote) If I could come up with a good quantitative measure of coupling strengths and plot it over scales, I would expect to see a substantial discontinuity at the scale of an animal, but little or none at the scale of an entire species.

And this, I suspect, is the philosophical trap hidden in Darwin’s approach. (Not to say that I disagree with the ideas of natural selection – they are predictive and good models of a wide variety of phenomena. My argument is with the philosophical approach that comes from in effect moralizing the existence of species and the notion of their reproductive competition) The next largest scale which seems to be significant after an organism is a biome, not a species; and in this context the reproductive function of the organism cannot be interpreted as primary, any more than eating or sleeping, since they are all repair and renewal mechanisms of a subsystem, more or less on a par. The “primary purpose” of an organism in such a context would be in terms of its operation on the rest of the biome to which it belongs.

I wonder if this idea can be made more systematic. It may give better modelling explanations for anti-procreative behavior (e.g. nonzero occurrence of homosexuality, locked adolescence in orangutans) in species than this very reproduction-oriented model which is so in favor today; it may also give some clearer pictures of what is a necessary component to animal (and human) behavior and what is accidental.

OK, end of random thought. Anyone have thoughts on this?

Published in: on July 15, 2004 at 23:31  Comments (13)  


  1. Damn, it’s sexy when you do that.

  2. So…..
    first off,you work a whoooole lot….i hope at some point you sleep. Or is sleep something you no longer need?
    So, onto the main topic of discussion: Species and boundaries. The Taoist side of me said,”why have boundaries at all? Everything is a part of everything else.” and then feel silent to drink some tea. The rest of this is coming from the more curious side.
    I love analogies and i like the body/cell, biome/species comparison, which I hope is essentially what you meant. It just stirs shapes in my mind. What stirs in my mind i am having trouble expressing. It seems to me that your thought is
    Cell = species
    which seems true and the darwin way is
    species = virus
    which also feels true. But certainly
    cell != virus
    So what am i left with? I am not sure. I think i am going to sleep on it though. for a day or two. Species seem like a Möbius strip to me at the moment – both inside and outside at the same time. I assume if the thoughts solidify i can prattle on here? And please if i have misunderstood anything,please let me know.

  3. I’m glad I kept reading, because towards the middle of that, I was starting to think you were suggesting that having sex with animals would produce stronger offspring.

  4. Re: So…..
    Well, the scaling I had in mind is essentially animal ~ cell, species ~ organ, biome ~ organism; the animal is a logical division point in its own right but a very small subnode of a biome, whereas the species is a mass of similar animals and has a function in the biome distinct from other species, but doesn’t have enough decoupling to really be an independent entity, much in the way that an organ doesn’t have as clear an identity as an organism.
    What do you have in mind as far as species ~ virus? I would say that a virus has substantial independence of operation, on a par with a cell.

  5. *cocks eyebrow*
    You know, there are other sorts of inter-species couplings. 🙂

  6. How can reproduction not be primary when ecosystems and niche competitors are affected by birth/replenishment and death/consumption rates of the prey and predator populations? Though species may eventually adapt to compete for and occupy other niches by learning to consume new food sources and thus fulfilling modified “functions”, reproduction still plays the central role in the survival strategy of the species as it determines rate of overpopulation or replenishment after population decimation.

  7. I’m not arguing that reproduction isn’t a very important function, but that from the ecosystem perspective, it’s part of the normal repair and growth functions of a subsystem, in the same way that eating and sleeping are repair and growth functions.
    My suggestion is more focused on your last statement, about survival strategies of the species. I suggest is that we shouldn’t attribute agency to a species; the natural division points are individual organisms and biomes.

  8. True indeed. And yet, my social circles don’t tend to discuss those….

  9. Hum, this is quite interesting. I’d love to discuss it in more detail at the next communal gathering we both attend. 😉

  10. Ooh, drunken philosophy! Sounds good. 🙂

  11. well….
    i have the drunken part….when do i get to see other people??? EVER…sigh…i guess i will have to have my own drunken get-to-gether right now…..
    i swim in the wrong circles….
    ps: shhh……i am drunk… 😛

  12. Ecosystems are, by nature adversarial and competitive. Reproduction, as a result, becomes central to survival strategy.
    If reproduction are the normal repair and growth functions of the subsystem, then how do we classify those apparently self-destructive “functions” that not only require repair and growth functions, but sometimes actually succeed in eliminating elements of the subsystem?
    I didn’t attribute agency to species. Survival strategies – whether reproductive, instinctive, etc – are coded in the genes of the species. These are, generally, species-wide survival strategies that are coded in the common DNA. There are traits and characteristics shared by members of the species. Reproduction is central to these traits and characteristics.

  13. Re: So…..
    God I have to learn to make time for lj….and hell,everything else….sigh…
    What I meant was that species span biomes in the same way a virus spans hosts. A virus does almost nothing but make copies of itself to spread even more copies. This would be the classic view,the darwin view you mentioned.
    What I took away from the post was a way of looking at species from the perspective of the biome to see how the biome shapes the species. What I meant but had a hard time expressing was how looking where both models overlap and where they diverge and how that helps craft the shape the species takes.
    Homosexuality for example makes questionable sense for a species (there are both good and bad points) but from a biome perspective it might be looked at as slowing a species that is successful,helping it not get out of control. War might be a similar example. Helpful to the local biome to reduce numbers and the species is encouraged to spread to other biomes, helping the species spread. I feel there are other examples that i have not yet crystallized into words. I could also be totally off my rocker.
    on a side note: the “locked adolescence in orangutans”…i couldn’t find anything doing a quick search on it(i must be using crappy search terms)…but it does tickle a memoery…dare i ask for a brief explanation?

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