Are species life forms?

This is a section of my forthcoming revision to Species, presented here for comments that I can steal – umm, I mean for peer commentary.

The philosophical ideas and terms of Wittgenstein have played an interesting and underappreciated role in the species debate: we saw Beckner appeal to family resemblance predicates, and Pigliucci revive that, as explanations of specieshood. I would like to appeal to another Wittgensteinian notion: forms of life (Lebensformen)[1].

In the Philosophical Investigations, Wittgenstein was discussing our ability to understand foreign points of view (including other minds) and famously said, “If a lion could talk, we could not understand him.” A little later he stated, “What has to be accepted, the given, is—so one could say—forms of life.”[2] For Wittgenstein, understanding another language-game depends upon shared points of reference in the form of life[3]. Since we do not share a Lebensform with a lion, his language-game would be opaque to us. However, any biologist would know that we do share a Lebensform with lions, and indeed all mammals, and more distally, all vertebrates, etc. And so, if we could speak lion, we would understand what he was saying to that degree of evolutionary relatedness[4].

The notion of a form of life has recently been applied to species by the neo-Aristotelian ethicist, Roland Sandler[5], as part of a justification of Aristotelian virtue ethics based upon the natural flourishing of organisms (especially humans, of course). Leaving to one side the ethical arguments, this is intriguing. What would it mean to say a species is a form of life? In the ordinary sense, that is a truism, but a Lebensform has much more than its appearance. A Lebensform is the sum total of the relations of the individual to its community, to its environment, and between its needs and parts, leading to typical development. In the general sense required for biology, the Lebensform of a species is the interrelations of members of the population with each other and with the ecological context and history of that population.

Any organism is a developmental system. That is to say, the outcomes of its development are not predetermined merely by its genes (genetic determinism is a kind of preformationism) but also by the environment in which it develops to maturity and further reproduction.[6] Susan Oyama wrote:

What shapes species-typical characters is not formative powers but a developmental system, much of which is bequeathed to offspring by parent and/or arranged by the developing organism itself. The same is true of atypical ones, which may result from developmental systems that are novel in some respect; an aberrant climate or diet may “play” on the genome in a different way, a mutation may eventuate in altered stimulus preferences or metabolic processes, thus altering the effective environment, etc.[7]

So, the issue with what makes a life-form is not that there is an “essential” set of biological properties in a given organism, but that the organismal outcome will depend on the interplay between endogenous and exogenous properties: genes, somatic inheritance, the abiotic environment, food sources availability at different developmental typical stages, parental investment, etc. In an approach named “niche construction”, several biologists have argued that preceding generations construct aspects of the organismic environment that can be usefully seen as inheritance for the organism, such as trackways, nests, cultural behaviors, and so on for animal species.[8] Thus, in addition to the usual gene+environment=phenotype “interactionist consensus”[9], there arises a complex system of feedback loops and effects that make an organism the organism it is. Oyama’s comment indicates that what “makes” a species includes, among other things, the extra-genetic heredity[10] within a metapopulation. In short, a biological life-form is not going to involve some uniquely shared set of properties, nor will it be the case that it is a social or cognitive construct[11]; it is part of a set or more or less stable processes that we observe and report.

Wittgenstein’s version of Lebensformen is that they have self-enclosed criteria for typical behaviors and cognitive styles, which are self-constructed through the use of language games[12]. It has no particular biological implications, and Sandler’s use of the term is based upon species having self-justifying natural goods. Here, however, we can appeal to some more generalized features of the concept – that species construct through their variable ways of making a living in their environment, the properties that we see are clustered together.

Parenthetically, Lebensform is also a term that has a non-Wittgensteinian history in biology, particularly in botany[13]. Eugenius Warming used it for the forms of vegetation[14]. Raunkiaer, a Danish ecologist, proposed what has come to be known as the Life-form spectrum, which was early adopted as a taxonomy of ecotypes[15]. It is still in use today. Helmreich and Roosth argue that the term has always held the implication of “a space of possibility in which life might take shape”, and so it is appropriate to employ it in this context.

Recognition of a Lebensform is still something that is done iteratively and recursively. And in line with the notion of a family resemblance predicate, it is not to be expected that there will be sharp or universal tests for delimiting species.



[1] Floyd 2016 presents the history and prior connections of the term in Wittgenstein’s development.
[2] Wittgenstein 1968, 223, 226. See Hunter 1968 for an analysis of the Lebensform concept as an “organic” (that is, developmental) notion. While Gier 1980 has argued that Hunter is incorrect in his biological exegesis of Wittgenstein, and notes that there is also a strong social and linguistic aspect to Lebensform with respect to humans in W’s work, we are free to interpret the notion organically as well in the present context, as W’s attitude to biology is not to be trusted (see below).
[3] “… if language is to be a means of communication there must be agreement not only in definitions but also (queer as this may sound) in judgements” Wittgenstein 1968, §242, 288.
[4] Wittgenstein was notoriously underwhelmed about evolutionary theory: “Darwin’s theory has no more to do with philosophy than any other hypothesis in natural science.” Wittgenstein 1922, 4.1122.
[5] Sandler 2007. I do not concur with Sandler that natural good is the Lebensform of a species, as it implies a natural state model of the evolution of each species. I appreciate Jay Odenbaugh’s providing me with this reference, and see his response to this approach which gives further references: Odenbaugh 2017.
[6] Griffiths and Gray 1994, Griffiths and Knight 1998, Griffiths and Stotz 2013.
[7] Oyama 2000, 139.
[8] Odling-Smee, Laland and Feldman 2003, Webb, Ackerly, McPeek and Donoghue 2002, Day, Laland and Odling-Smee 2003. See philosophical commentary on this view: Griffiths 2002, Okasha 2005, Barker 2008.
[9] Sterelny and Griffiths 1999, §5.3, Kitcher and Sterelny 1988.
[10] The usual term in this case is “epigenetic”. As “epigenetic” is used in multiple ways, I would prefer to restrict it to gene methylation and closely similar processes, to avoid confusion.
[11] That is, it will not be just a cognitive or social construct. Pretty well everything that is thought, in science or society in general, is at least a cognitive and social construct; something else that Wittgenstein noted in his later philosophy.
[12] Lebensform is one of a number of similar concepts such as Worldview, Paradigm, Belief System, and so forth, in which the criteria for justification, sense, or inclusion are determined by a comprehensive set of beliefs that are incommensurate with other such sets. Wittegenstein’s comment about the lion talking is meant to show the complete intranslatability of lion-talk and people-talk; but, as I have argued, on biological grounds, lions and humans share a considerable homology and analogy of lifestyles and interests such that we can understand a fair bit about their signalling calls.
[13] Helmreich and Roosth 2010.
[14] Warming 1895.
[15] Raunkiær 1934, Smith 1913.

References

Barker, G. 2008. “Biological Levers and Extended Adaptationism.”  Biology and Philosophy 23 (1):1–25.

Day, R. L., et al. 2003. “Rethinking Adaptation: The Niche-Construction Perspective.”  Perspectives in Biology and Medicine 46 (1):80.

Floyd, J. 2016. “Chains of Life: Turing, Lebensform, and the Emergence of Wittgenstein’s Later Style.”  Nordic Wittgenstein Review:7-89.

Gier, N. F. 1980. “Wittgenstein and Forms of Life.”  Philosophy of the Social Sciences 10 (3):241-258. doi: 10.1177/004839318001000301.

Griffiths, P., and K. Stotz. 2013. Genetics and philosophy: an introduction. Cambridge: Cambridge University Press.

Griffiths, P. E. 2002. “Beyond the Baldwin Effect: James Mark Baldwin’s ‘social heredity’, epigenetic inheritance and niche-construction.” In Learning, Meaning and Emergence: Possible Baldwinian Mechanisms in the Co-evolution of Mind and Language, edited by B. Weber and D. Depew.

Griffiths, P. E., and R. D. Gray. 1994. “Developmental systems and evolutionary explanation.”  Journal of Philosophy 91 (6):277–304.

Griffiths, P. E., and R. D. Knight. 1998. “What is the developmentalist challenge?”  Philosophy of Science 65 (2):253–258.

Helmreich, S., and S. Roosth. 2010. “Life Forms: A Keyword Entry.”  Representations 112:27–53.

Hunter, J. F. M. 1968. “”Forms of Life” in Wittgenstein’s “Philosophical Investigations”.”  American Philosophical Quarterly 5 (4):233–243.

Kitcher, P., and K. Sterelny. 1988. “The Return of the Gene.”  Journal of Philosophy 85:339–361.

Odenbaugh, J. 2017. “Nothing in ethics makes sense except in the light of evolution? Natural goodness, normativity, and naturalism.”  Synthese 194:1031–1055. doi: 10.1007/s11229-015-0675-7.

Odling-Smee, F. J., et al. 2003. Niche construction: the neglected process in evolution, Monographs in population biology; 37. Princeton, N.J.: Princeton University Press.

Okasha, S. 2005. “On Niche Construction and Extended Evolutionary Theory.”  Biology and Philosophy 20 (1):1–10.

Oyama, S. 2000. The ontogeny of information : developmental systems and evolution. 2nd ed, Science and cultural theory. Durham, N.C.: Duke University Press.

Raunkiær, C. C. 1934. The Life Forms of Plants and Statistical Plant Geography. Being the Collected Papers of C. Raunkiaer. Translated by H. G. Carter, et al. Oxford University Press: Oxford.

Sandler, R. L. 2007. Character and Environment: A Virtue-Oriented Approach to Environmental Ethics. New York: Columbia University Press.

Smith, W. G. 1913. “Raunkiaer’s “Life-Forms” and Statistical Methods.”  Journal of Ecology 1 (1):16-26. doi: 10.2307/2255456.

Sterelny, K., and P. E. Griffiths. 1999. Sex and death: an introduction to philosophy of biology. Chicago, Ill. ; London: University of Chicago Press.

Warming, E. 1895. Plantesamfund – Grundtræk af den økologiske Plantegeografi. Kjøbenhavn: P.G. Philipsens Forlag.

Webb, C. O., et al. 2002. “Phylogenies and Community Ecology.”  Annual Review of Ecology and Systematics 33:475–505.

Wittgenstein, L. 1922. Tractatus logico-philosophicus. London: Kegan Paul, Trench, Trubner & Co.

—. 1968. Philosophical investigations. Translated by G. E. M. Anscombe. Repr. of [3rd ed.] English text, with index. ed. Oxford: Basil Blackwell.

7 thoughts on “Are species life forms?

  1. Very interesting. I remember someone having commented that “evo-devo” doesn’t really apply to single-celled organisms, but I think it does for the reasons mentioned above. Interactions with the environment can promote transcription or gene duplication and change surface receptors. Organisms can even ingest plasmids and other foreign DNA.

    I need to ponder this more.

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    1. Single celled organisms like Plasmodium often have multi stage lifecycles (mating types). Moreover, community-based single celled organisms like Dictyostelium (slime molds) will change their expression and phenotype in different conditions.

      Like all evolved processes, there are borderline conditions where it becomes hard to say it is or isn’t some paradigm state.

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    2. Nick Lane in the Vital Question discusses how prokaryotes can acquire suites of genes for surviving in novel environments.

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  2. As far as I can tell, “lifestyle” is Lebensweise or Lebensstil, at least in modern usage. But I reckon it seems to carry some of the flavour of Lebensform, and is frequently used in technical discussions about (essential?!) characteristics of a species. Examples from Google Scholar:

    “…parasitism as the most common lifestyle on Earth and…a significant proportion of the worlds species are parasites. Parasitism is indeed a lifestyle and not a phylogenetic category”

    “lifestyle (free-living species, parasites or mutualist symbionts)”

    “[the bacterial] starvation-survival lifestyle”

    “The hemibiotrophic lifestyle”

    “burrow dwelling lifestyle”

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    1. Lifestyle is more an ecological notion than a taxonomic one. Life-form is, I think, better. However, the German literature is not consistent over the years [nor the Anglophone].

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