Culturally adapting opportunists, or On the diversity of ecological niches of Homo sapiens Linnaeus, 1758. Column for Computerra #116

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Culturally adapted opportunists, or On the diversity of ecological niches of Homo sapiens Linnaeus, 1758 Six traditional ecological niches and six social worlds of humanity's traditional cultures Column for Computerra #115 Column for Computerra #116 Column for Computerra #117 Generally speaking, in this column (and to an even greater degree in the next) I plan to intrude onto territory where I am an amateur.

I plan to discuss the diversity of ways of life characteristic of human populations in different epochs and different regions.

What I will talk about belongs to some extent to the sphere of interest of economic theory, cultural studies, anthropology and other sciences. In discussing the problems that interest me, specialists in other sciences speak of types of culture, economic structures, modes of production, economic systems, and so on, and so on. How am I to show that what interests me is precisely the ecological aspect of the relations of human groups with their environment? I will speak of the diversity of ecological niches of human populations. By means of this simple trick I will enter the little-known territory lying between the humanities and the natural sciences from "my own" territory. I will have to begin with what an "ecological niche" is: "The phrase 'ecological niche' was first used by J. Grinnell in 1917. He thus designated the characteristic habitat of a species, the set of conditions in which a particular species occurs in nature. C. Elton in 1927 defined the ecological niche as a species' place in the community, its position in the structure of trophic relations. G. Hutchinson in 1957 presented the ecological niche as the set of all values of ecological factors that permit the existence of the species. Finally, E. Odum explained that a niche is a characteristic of a species' requirements for its environment and of its inherent way of life." As you have understood, I will speak of the ecological niche as the character of relations with the environment of habitation. This concept is applicable to biosystems of different levels of organization. First of all, of course, it concerns species and populations: relatively isolated, evolving, potentially immortal living systems that inhabit our planet. At the same time, one can quite legitimately raise the question of the specialization of an individual within a population's niche, as well as discuss niches characteristic of certain supraspecific groups. Oddly enough, the question of the ecological niches of our species remains insufficiently developed. A search of the Runet for the corresponding phrase yields scanty and disappointing results. One of the few pleasant exceptions is an anonymous (at least I did not find the author's name) textbook of human biology, created for the St. Petersburg Social-Psychological Centre and posted on the site "Ethology.ru". "A unique feature of our genus is that over several million years of evolution we did not take the path of specialization for a particular ecological niche, but changed them." So, over the course of its history our species changed its ecological niches. Having acknowledged this fact, we immediately face the need to classify these niches, to describe their dynamics, to find out how they are connected with other characteristics of humans. Here a rather broad opportunity for self-knowledge opens up before us. …Several million years ago relatively large forest apes were mastering the open spaces of the African savannas. These were animals with extraordinarily complex behaviour. Probably they could form conditioned reflexes on the basis of a single event, and were also capable of transmitting acquired experience from individual to individual through cultural inheritance. Sometimes such cultural inheritance was simple "aping" (copying a particular model), and sometimes a quite regular teaching of younger individuals by older ones. These apes were characterized by living in groups with individualized relations between each individual and a fine differentiation of roles. On what grounds have I confidently ascribed the listed characteristics to the groups of our ancestors and their various relatives? These are general features characteristic of us and of other members of our family. It seems that the most important feature of the line that led to us was the exceptional diversity of the methods of feeding available to its representatives. Five species of our family now live on Earth; besides Homo sapiens, these are orangutans, gorillas, chimpanzees and bonobos. The most varied behaviour is that of chimpanzees; probably our ancestors significantly surpassed today's chimpanzees in the plasticity of their behaviour. Different groups, owing to their prehistory (which included, among other things, simply the totality of chance events that befell their members), transmitted different experience from generation to generation by means of cultural inheritance. This cultural fund of populations itself became an important factor in their evolution. For example, a group that specialized in one method of feeding (say, taking carcasses of animals from predators) acquired a whole series of cultural traditions that increased the efficiency of such a way of life, and eventually specialized in it. A group oriented toward gathering molluscs, crustaceans, amphibians and fish — whether dead or alive — along the shores of water bodies acquired features that directed it down this path. And, time and again, different methods of feeding were characteristic of one and the same group, reflecting the difference of the seasons or the specialization of the sexes. In the arid, changeable and hard-to-predict environment of the African savannas, an important property of cultural inheritance proved to be in demand — the speed of producing and spreading new traits. Cultural inheritance is much faster than genetic. I will explain this with an example. Rinsing food of sand and dirt before consumption is characteristic of several groups of animals. Raccoons rinse their food; in them this behaviour is set instinctively. A raccoon raised in isolation will in time begin to rinse its food in water. Japanese macaques from one population, observed over the long term, rinse their food. In them this trait is transmitted culturally: researchers recorded the moment when a young female dropped a tuber into the water and connected this circumstance with the fact that her food had been cleaned of sand, and then observed the spread of this skill among her kin. How long and in what way the instinct of food-rinsing was formed in raccoons, I do not know. The generally accepted explanation of this process must include a set of assumptions about the reasons for which the capacity for primitive food-rinsing could arise; a mention of the multitude of generations in which "washing" and "non-washing" raccoons coexisted; an assessment of the advantage by which the "washers" wore down their teeth less and either lived longer, or brought forth more offspring at a time, or more effectively charmed their potential partners. In any case it is a long song, incomparable with the history of the cultural acquisition of an analogous trait. From the first tuber that fell into the water to the spread of the capacity for food-rinsing in most individuals of the population, the lifetime of a single generation was enough! Why did the sphere of cultural inheritance in chimpanzees prove limited, while in our species it produced something fundamentally new? Perhaps it is simply chance. Sooner or later one species had to cross the threshold after which evolution rolls toward specialization in non-specialization and reliance on cultural inheritance. The diversity of feeding methods and the capacity for cultural inheritance are connected by positive feedback: the growth of one of these parameters promotes the growth of the other. By the way, one could assume that from the group that first moves to the evolution of unspecialized behaviour through cultural inheritance, a single species will ultimately remain. The coexistence of species is most often connected with the division of ecological niches, with their different specialization. The maximally flexible representative of such a group must sooner or later have displaced all its possible competitors. This species is our species, Homo sapiens Linnaeus, 1758. So, we arose as opportunists (creatures that exploit the various opportunities that open up before them) that adapt primarily through cultural inheritance. The primary niche for us became that of the hunter-gatherer, including a multitude of local variations. The "we" I have used refers to a community broader than our species. About one and a half million years ago this niche was occupied by the most successful (in terms of the duration of its existence) human species — "Pithecanthropus", Homo erectus. This species settled the vastest expanses of Africa and Asia, mastered seafaring and existed for considerably more than a million years. Local populations of erectus evolved in different directions, giving rise to new species. From African erectus, either directly or through stages that should be distinguished as other species, our species too arose about 200 thousand years ago. Its archaic representatives are assigned to the subspecies H. sapiens idaltu, and modern ones to H. sapiens sapiens. Some of the human species related to us occupied ecological niches clearly different from ours; some were our direct competitors. Declining to discuss the wonderful vicissitudes of the evolution of niches in our family and genus, let us turn to a consideration of the ecological evolution of our species. From a certain moment on, we can look at our way of life both "from outside" (comparing the niches of different species) and "from inside" (comparing the types of economy of different groups of people). And here we can see that not only for our species, but for the overwhelming majority of species of other animals, an appropriative economy is characteristic. We appropriate resources that appeared without our participation: an antelope half-eaten by lions, a dead fish on the shore of a drying lake, the air that plants have enriched with oxygen, or the oil reserves created by the forces of the earth's depths and the work of bacteria. Economists also distinguish a productive economy, meaning first of all the production of food in the course of agriculture and animal husbandry. Unfortunately, with regard to a number of resources we have remained appropriators just as we were. Even in our nutrition the share of appropriation is still large: have you eaten ocean fish raised in the open sea recently? And as for water, air, space, soils and minerals, we continue to appropriate what we have managed to master. So, by the way, are all other animals without exception appropriators? I doubt it. In various groups of ants, at least, analogues of both animal husbandry (the rearing, protection and use of aphids by red wood ants) and crop-growing (the cultivation of domesticated fungi on plant biomass, characteristic of leaf-cutter ants) have been recorded. One way or another, we proved very successful. And, following H. erectus, H. sapiens became an invasive species, widely settling beyond its original range. Whether the concept of an invasive species is applicable to humans is a debatable question. The term itself is not simple to interpret unambiguously (for its analysis with respect to plants — see here). Probably the important characteristics of invasiveness are the alienness of species to the territory under consideration, their capacity for dispersal and for changing their new habitats. Sometimes the characteristic of invasiveness includes the fact that the dispersal of such a species is connected with human activity. In my opinion, this is a superfluous (and ambiguous) qualification. It is best to explain my point of view with an example. In the vicinity of the biological station of Kharkiv University, in the channel of the Siverskyi Donets (the largest river of Eastern Ukraine), an invasion of an Afro-Asian plant species is observed — water lettuce, Pistia stratiotes. Pistia got into the Siverskyi Donets from Kharkiv, and most likely was introduced there by aquarists. Now this plant is spreading downstream. Fortunately, in some places jams form on the river that hold back its spread. Perhaps in winter the pistia will freeze out; perhaps it will adapt and noticeably change conditions in the Donets. For now the spread of pistia is a problem of two districts of the Kharkiv region. But if this plant is lucky, it will be able to settle further downstream — into the Donetsk and Luhansk regions of Ukraine, as well as the Rostov region of Russia. The Siverskyi Donets flows into the Don; in the lower reaches of the Don the pistia will have a much greater chance of overwintering. Whether we consider its invasion a manifestation of human activity (for example, of plants released into the Udy, a tributary of the Siverskyi Donets, within the city of Kharkiv) or a consequence of natural dispersal that may carry this newcomer to the Don is unimportant. One way or another, the invasion of pistia changes the ecosystems of the rivers it has entered. The invasion of humans led to far deeper changes in ecosystems. The dispersal of humans was often closely connected in time with the extinction of the megafauna — that is, the fauna of large animals that were the most attractive game for ancient humans. Our role in the disappearance of the megafauna of Africa, Eurasia, America and Australia is still debated; in different cases both arguments testifying to our "guilt" and evidence of the role played by climate change have been obtained. The "hunting" and "climatic" versions are not alternatives and can complement each other. But, one way or another, our species faced an ecological catastrophe that made it impossible to maintain its numbers at the previous level. We survived by mastering new niches.

Which ones exactly, and how — I will tell another time.

There is reason here for a serious conversation… ← Dmytro Shabanov → How will biology and other worldview-significant sciences be studied in the kind of school of the future that is worth dreaming of?

Culturally adapted opportunists, or On the diversity of ecological niches of Homo sapiens Linnaeus, 1758 Six traditional ecological niches and six social worlds of humanity's traditional cultures Column for Computerra #115 Column for Computerra #116 Column for Computerra #117