Invasive species and natural function in ecology

Abstract

If ecological systems are functionally organised, they can possess functions or malfunctions. Natural function would provide justification for conservationists to act for the protection of current ecological arrangements and control the presence of populations that create ecosystem malfunctions. Invasive species are often thought to be malfunctional for ecosystems, so functional arrangement would provide an objective reason for their control. Unfortunately for this prospect, I argue no theory of function, which can support such normative conclusions, can be applied to large scale ecosystems. Instead ecological systems have causal structure, with small clusters of populations achieving functional arrangement. This, however, does not leave us without reason to control invasive species. We can look at the causal arrangement of ecological systems for populations that support ecological features that we should preserve. Populations that play a causal role in reducing biodiversity should be controlled, because biodiversity is a good all prudent agents should want to preserve.

Two Notions of Ecological Function

“…Related issues are whether communities and ecosystems may legitimately be regarded as functionally organized entities or systems and the extent to which our understanding of their functional organization should be based in evolution. Proponents of the consensus view also differ over whether their accounts are focused on communities (Maclaurin and Sterelny 2008;Lean 2020), or on ecosystems (Odenbaugh 2010;Nunes-Neto, Moreno, and El-Hani 2014;Dussault and Bouchard 2017;Dussault 2018).…”

“…Hence, ecological functions as contributions to community maintenance or ecosystem functioning seem better construed as non-selectedeffects functions, functions that organisms, populations, and abiotic items fulfill without necessarily having been shaped by natural selection to fulfill them. They are functions along the lines of alternatives to the selected-effects theory, such as the causal role, the organizational, or the contribution to fitness theory (see Maclaurin and Sterelny 2008;Odenbaugh 2010;Nunes-Neto, Moreno, and El-Hani 2014;Dussault and Bouchard 2017;Lean 2020).…”

“…6.2;Odenbaugh 2010, sec. 3;Nunes-Neto, Moreno, and El-Hani 2014;Dussault and Bouchard 2017;Dussault 2018;Lean 2020). Despite the novelty of the topic, philosophers who have contributed to it seem to have reached an "implicit consensus" (see Nunes-Neto, Moreno, and El-Hani 2014, 124;Dussault 2018, 2-3).…”

The evolution of multispecies populations: a multilevel selection perspective

“…The point is that communities comprised of horizontally assembled individuals are not distinct units of selection because they lack the necessary parent-offspring resemblances associated with vertical inheritance. And because such communities do not reproduce as communities, they cannot be construed as units of selection (Maclaurin and Sterelny 2008;Lean 2020, cf. Bouchard 2014, cf.…”

A Causal-Role Account of Ecological Role Functions

“…Role functions in ecology—the roles of species or other ecosystem components that help explain ecosystem behavior—have recently gained attention among philosophers of biology (Odenbaugh 2010; Nunes-Neto and El-Hani 2011; Saborido et al 2011; Nunes-Neto et al 2014; Nunes-Neto, Freitas, Saborido, et al 2016; Dussault and Bouchard 2017; Dussault 2018; Odenbaugh 2019; Lean 2021; Millstein 2020). In this article, I develop a new account of ecological role functions.…”