Making an environment 83
that, in the absence of concrete constraining factors, would be compatible with
the continued existence of the species under consideration, and it will thus be
filled by the suitable ranges of these values. The realised niche is the sector of
this hypothetical hypervolume that is circumscribed by a given set of concrete
constraining factors. Realised niches, then, are always subject to the whims of the
current conditions of realisation, and may change over time or may be changed by
the organisms, for better or for worse. On the level of realised niches, a dynamic
aspect enters the conception of ecological niches that allows for the notion of
niches being modified by their inhabitants. On the level of fundamental niches,
evolutionary change of the constitution of a species will be the exclusive provider
of dynamics. In addition, specificity is acknowledged in terms of the variable
dimensions and extension of the mathematical spaces of both fundamental and
realised niches for each species. However, these notions are not systematically
elaborated with respect to the possibility of organisms modifying the dimensions
and extension of that space.
The Grinnellian, Eltonian and Hutchinsonian niche concepts are, first, partly
idealising in an unfavourable way in that they abstract from concrete conditions
of realisation and the specific properties and activities of specific organisms. In
the case of Hutchinsonian niches, this critique applies to the notion of the fundamental niche, whereas the Grinnellian niche concept is altogether exempt from
it. Second, these definitions are static to the extent that they do not sufficiently
account for the possible effects of the behaviour of organisms on the shape of a
niche, with partial exemption for Hutchinson’s realised niches.
It is these two points on which Richard Lewontin’s critique of what he deems
the received view of organism-environment relations, and hence ecological niches,
picks up. He argues that an environment is not merely a set of pre-existing conditions to which organisms would adapt in reactive fashion, by the trial-and-error
process of random variation and natural selection. If this were so, those external
conditions would be the fixed problems to which their adaptations were the fixed
solutions (Lewontin 1982, 162). Conversely, an organism’s traits, on the view
criticised by Lewontin, would “map the demands of the environment through
adaptation” (2000, 47). Instead, an environment, on the Lewontian view broadly
shared here, is both dynamic in bi-directional fashion and specific to an organism:
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.
(Lewontin 2000, 48f )
To illustrate this point, Lewontin notes that one would find it hard to describe the
environment of an organism without first describing the activities of that organism
(Lewontin 2000, 50f ). In his earlier essay on the same topic, he goes one step further when he says: “Indeed, an environment is nature organized by an organism”
(Lewontin 1982, 160) – a view that may be aptly labelled as “environmental constructivism”. Environmental construction, on Lewontin’s account, will include
that, in the absence of concrete constraining factors, would be compatible with
the continued existence of the species under consideration, and it will thus be
filled by the suitable ranges of these values. The realised niche is the sector of
this hypothetical hypervolume that is circumscribed by a given set of concrete
constraining factors. Realised niches, then, are always subject to the whims of the
current conditions of realisation, and may change over time or may be changed by
the organisms, for better or for worse. On the level of realised niches, a dynamic
aspect enters the conception of ecological niches that allows for the notion of
niches being modified by their inhabitants. On the level of fundamental niches,
evolutionary change of the constitution of a species will be the exclusive provider
of dynamics. In addition, specificity is acknowledged in terms of the variable
dimensions and extension of the mathematical spaces of both fundamental and
realised niches for each species. However, these notions are not systematically
elaborated with respect to the possibility of organisms modifying the dimensions
and extension of that space.
The Grinnellian, Eltonian and Hutchinsonian niche concepts are, first, partly
idealising in an unfavourable way in that they abstract from concrete conditions
of realisation and the specific properties and activities of specific organisms. In
the case of Hutchinsonian niches, this critique applies to the notion of the fundamental niche, whereas the Grinnellian niche concept is altogether exempt from
it. Second, these definitions are static to the extent that they do not sufficiently
account for the possible effects of the behaviour of organisms on the shape of a
niche, with partial exemption for Hutchinson’s realised niches.
It is these two points on which Richard Lewontin’s critique of what he deems
the received view of organism-environment relations, and hence ecological niches,
picks up. He argues that an environment is not merely a set of pre-existing conditions to which organisms would adapt in reactive fashion, by the trial-and-error
process of random variation and natural selection. If this were so, those external
conditions would be the fixed problems to which their adaptations were the fixed
solutions (Lewontin 1982, 162). Conversely, an organism’s traits, on the view
criticised by Lewontin, would “map the demands of the environment through
adaptation” (2000, 47). Instead, an environment, on the Lewontian view broadly
shared here, is both dynamic in bi-directional fashion and specific to an organism:
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.
(Lewontin 2000, 48f )
To illustrate this point, Lewontin notes that one would find it hard to describe the
environment of an organism without first describing the activities of that organism
(Lewontin 2000, 50f ). In his earlier essay on the same topic, he goes one step further when he says: “Indeed, an environment is nature organized by an organism”
(Lewontin 1982, 160) – a view that may be aptly labelled as “environmental constructivism”. Environmental construction, on Lewontin’s account, will include