THIS POST IS PART OF OUR ANTHROPOCENE BIOSPHERE PROJECT–A SERIES OF POSTS ON ERLE ELLIS’ ‘ECOLOGY IN AN ANTHROPOGENIC BIOSPHERE‘ (ECOLOGICAL MONOGRAPHS, 85/3 (2015))

In ‘Ecology in an Anthropogenic Biosphere’ Erle Ellis posits “’The First Law of the Anthropocene’: the ecological patterns, processes, and dynamics of the present day, deep past, and foreseeable future are shaped by human societies” (p. 316). The goal of the paper is to explain why this law holds—i.e. to explain what it is about this particular species, homo sapiens, that gave it “the capacity to transform an entire planet” (p. 288). The key to Ellis’ explanation—at least as I see it—is in the character of the specifically human mode of habitation, namely that human beings occupy, because they construct, a “sociocultural niche.” In this post I want to try to deepen my understanding of the niche concept, in order to grasp better what Ellis means by describing the human niche as sociocultural. I think that the Pinker article, which Ellis cites in reference to social learning (p. 298) also sheds light on how Ellis is using the idea of the niche. I offer my interpretation in hopes that readers will offer corrections of my misunderstandings.

Pinker argues that the solution to the puzzle of the evolution of the human mind lies with the theory of the “cognitive niche.” This theory, he holds, explains the evolution of three key and distinctively human traits: use of technology, cooperation among non-kin, and communication by means of a grammatical language. Ellis implicitly refers to the last of these three traits as the basis of “the unrivalled capacity of humans to transmit information by social learning” (p. 298). And he also cites the importance of non-kin cooperation (p. 298) and technology (pp. 300 ff.). Thus, things Pinker has to say about specific aspects of the cognitive niche bolster Ellis’ presentation of the corresponding aspects of the sociocultural niche.

However, at a more conceptual level, what is especially helpful to me is that Pinker’s explanation of the cognitive niche idea improved my grasp of the underlying idea of the niche, thus helping me see how Ellis’ sociocultural niche is likewise an elaboration of that underlying idea.

Pinker starts with a basic notion of a niche as “the role an organism occupies in an ecosystem” (p. 8993). Focusing on animals, that role, put crudely, is to eat other organisms—which in turn will have some defenses against being eaten. But the niche idea should not be understood primarily in physical terms, as the surroundings of a given animal, containing its food. Rather an animal’s niche should be understood in functional terms: what, in its surroundings, its particular capabilities render available for it to eat. An animal’s niche, that is, is a function of its capabilities—its niche is constituted by the physical features of its surroundings that it is able to take advantage of to survive. I believe this is what Richard Lewontin means when he says “The environment of an organism is the penumbra of external conditions that are relevant to it because it has effective interactions with those aspects of the outer world” (2000, p. 49).

A fundamental aspect of the niche idea, then, is that it is the set of resources that support a creature’s survival—given its metabolic needs and its capabilities for fulfilling them. This is a narrowly ecological conception of the niche. But there is another fundamental aspect that Pinker identifies, associated with evolution. For a niche places selection pressure on its inhabitants: individuals that are not well adapted to it will not pass their genes to succeeding generations, so that those generations will be better adapted, or not exist. And, as features of the niche change (e.g. a prey species develops better defenses), natural selection leads to the evolution of traits adapted to those changes.

This second aspect is the focus of “Niche Construction Theory,” which has been a recurring topic on this blog. NCT examines how animals actively create niches by modifying their surroundings to suit their metabolic needs—and observes that those modified environments serve as an “ecological inheritance” passed on to succeeding generations, which must remain adapted to them. In Pinker’s words, “An organism’s behavior alters its physical surroundings, which affects the selection pressures, in turn selecting for additional adaptations to exploit that altered environment, and so on. A classic example is the way beavers generated an aquatic niche and evolved additional adaptations to thrive in it” (p. 8995).

How then does the notion of the cognitive niche modify the underlying niche idea? In the underlying sense, the niche is characterized by a species’ capabilities for gaining the resources it needs from its surroundings. Let’s say a new physical trait appeared in a species—e.g. by a mutation yielding the ability to run faster, hence to capture a new type of prey. This would unlock a previously unavailable possibility for gaining survival, thereby adding a new dimension to the species’ niche. This same pattern can work with a non-physical trait, like improved cognitive abilities. As Pinker puts it, “In any ecosystem, the possibility exists for an organism to overtake other organisms’ fixed defenses by cause-and-effect reasoning and cooperative action—to deploy information and inference, rather than particular features of physics and chemistry, to extract resources from other organisms” (pp. 8993-94). Of course this is the possibility that humans exploited to gain an advantage over the species they relied on to survive; the collection of resources they gained access to in virtue of their cognitive abilities thus constitute a “cognitive niche.”

The cognitive niche idea conveys the notion that human evolution brings something new into the world: it adds a new non-physical dimension to the physical features of the biosphere that support metabolic survival. This is not to propose a mind-body dualism whereby cognition is metaphysically distinct from physical processes; as philosophers say, cognition “supervenes” on processes in the brain (and, as Pinker discusses, has a genetic substrate (p. 8996)). Rather, it is to say that there is a layer of cognitive representations through which human beings reach the physical resources they require. Those representations constitute an additional aspect of the human environment: people do not eat their internal representations of prey, but they do need to represent their prey internally to be able to eat them. The capacity to enter into the world of representation (a capacity that of course is tightly bound up with sociability) becomes, therefore, the key adaptation humans use to survive—and just as beavers adapted to the aquatic niche their forebears constructed, “initial increments in cooperation, communication, or know-how altered the social environment, and hence the selection pressures, for ancestral hominids,” (p. 8995) leading to distinctively human cognitive capacities. Thus, that which humans are adapted to is not simply the physical setting they inhabit, but this non-physical, cognitive world through which they inhabit it.

Pinker thus helped articulate for me what might be called the “noetic quality” of the human niche, i.e. ways the human niche cannot be understood in strictly metabolic terms, but requires an additional, mental (and social) set of categories, which nonetheless are directed at explaining human metabolic survival and evolution. Ellis’ “sociocultural niche” is perhaps a more complex concept than Pinker’s cognitive niche—but I believe it conforms to this general pattern of adding a noetic layer (or layers) to a fundamentally metabolic and Darwinian account of human life. In particular, Ellis speaks of culture in terms of information (see, e.g., his Table 1, pp. 292-293)—representations grasped, manipulated, and communicated via mental capacities. Pinker’s account helped me grasp more completely just what this means when Ellis speaks of the sociocultural system as a niche.

But I’ll conclude by noting a way in which Pinker points to a way Ellis might develop his theory his further. For Pinker starts and ends his paper with discussions of a puzzle posed by A.R. Wallace, the co-discoverer with Darwin of natural selection. The puzzle has to do with a mis-match between the skills needed for metabolic survival, and the intellectual accomplishments for which human beings take pride in their species. In Pinker’s words, “why do humans have the ability to pursue abstract intellectual feats such as science, mathematics, philosophy, and law, given that opportunities to exercise these talents did not exist in the foraging lifestyle in which humans evolved and would not have parlayed themselves into advantages in survival and reproduction even if they did?” (p. 8993). Wallace took those “higher” capacities than are needed for survival as evidence for Design. Pinker rejects that claim, arguing instead “that the psychological faculties that evolved to prosper in the cognitive niche can be coopted to abstract domains by processes of metaphorical abstraction and productive combination, both vividly manifested in human language” (p. 8993).

Pinker’s argument here is intricate and ingenious, but I will not summarize it here (see pp. 8996 ff.). Rather, I want to propose that Ellis might consider an analogous problem, and whether his theory contains the resources for an analogous solution. That is, we can ask whether the theory of cultural evolution Ellis offers, even if sufficient for explaining the evolution of a characteristically human way of making a living from the planet, and the ecological changes that result, succeeds at reaching “into” culture to account for cultural accomplishments that are not strictly necessary to survival. Does Ellis’ theory allow for something like Pinker’s move, whereby cultural elements that are adaptive in a narrow sense can be abstracted and combined to produce the cultural expressions we associate with the highest human achievements?