A short selection from Essay Eighteen in Darwin, Dogen, and the Extremophile Choice.
In considering transitions of organs [and thus, by extension, species], it is so important to bear in mind the probability of conversion from one function to another  … [and from the next chapter] Domestic instincts, as they may be called, are certainly far less fixed or invariable than natural instincts; but they have been acted on by far less rigorous selection, and have been transmitted for an incomparably shorter period, under less fixed conditions of life.  —Charles Darwin
Now, just so my introduction to Zen-natural history doesn’t get hijacked by reflexive schools of thought involving ‘no-harm’ and ‘oneness’ (and it’s worth noting that curious onlookers normally commit to mindfulness practice only after discovering within themselves the universal calamity of unexamined reflexes), I need to broach a complex double distinction: between bodies and behaviours as they respectively affect the evolution of ecosystems, and between their respective ‘mortalities’, by which I mean the birth and death of organisms vs. the arising and passing away of thoughts (i.e. covert behaviours, see: https://www.extremophilechoice.com/2018/03/16/the-importance-of-a-body-for-ai-and-for-what-it-means-to-be-human/) Darwin postulated that structural change must always follow a functional shift to argue his case that species do in fact evolve: that the natural world changes.  Here I want to remind the reader that, implicit in Darwin’s formulation, we have an argument that, when considering the everyday stability of species and ecosystems, it is also “important to bear in mind” that an organ’s “conversion from one function to another” must not happen without an ecologically sound reason. This is achieved during normal times, or under “fixed conditions of life” as Darwin himself put it, by the rigorous selection of natural instincts.  What this means, for any animal in an undisturbed and fully diversified biosystem, is that ultimately its structure is more reliable than its behaviour (which, no matter how instinctive, will always be “less fixed or invariable” than its body) for maintaining long-term ecological stability. So now, when we ask what does it mean to be human in the Natural world, it soon becomes a pivotal issue whether or not natural selection’s everyday priority is to limit behavioural flexibility by pruning out all behaviours that don’t conform to species-normal body structures. For if the answer is yes, then it becomes obvious that technology compels a radical departure from this Natural state of affairs, and this must not be overlooked by holding to a sentimental (and indeed self-serving) Man-As-Part-Of-Nature Environmentalism.
- Darwin, Charles. 1968 [First edition, John Murray 1859]. The Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life. London: Penguin Books. p. 221.
- Ibid, p. 239.
- Ibid, pp. 220-221.
- Ibid, p. 115.