Thomas park as a hybrid and transitional compositional-formal figure
Thomas Park combined a deep understanding of the biology of populations with a strong interest in formal statistical and analytical aspects of the same. He did 'not think it necessary' to 'dwell at length upon the biological reality of the population' (Park 1939, 235). To him, that was an obvious fact: 'I consider the population as much a biological unit as the organism.' (1942, 137). Specifically, he listed five 'biological properties', which in Allee et al. 1949 (Chapter 18, 264) he further claimed were 'exhibited by population and organism alike'. The five properties of a population are that a population:
'(1) possesses a definite structure and composition, constant for any moment of time but fluctuating with age; (2) is ontogenetic, exhibiting growth, differentiation and division of labor, maintenance and death; (3) is genetic, inheriting from each preceding generation a system of gene frequencies; (4) is integrated and coördinated; and (5) meets, as a unit, the full impact of the environment which may modify it and which, in turn, it may modify' (1939, 235; for a very similar list, see Allee et al. 1949, 264, footnote 13 above).
These are, to a large extent, indeed organismic properties. In addition, he presents a highly 'organismic' diagram that depicts 'the integrative factors that through their interaction control the size of the population during the entire course of its life-history' (cite on Park 1942, 122; diagram on Park 1942, 123; Allee et al. 1949, 390; see my Diagram 2). There is no question that Park shared the compositional and hierarchical organismic framework of the fellow members of the Chicago Ecology Group.
However, Park was also an essential figure in formalizing ecology, and that can already be gleaned from his 1939 and 1942 texts, in addition to the chapters he contributed to Allee et al. 1949. He provided an apology:
'I should feel that I had failed if I left the impression that, while integration in the organism is biological, integration in the population is statistical and, by that token, the two are not in any sense comparable. This would be fallacious. The dynamics of populations are equally biological but they are best expressed in statistical terms. Evolution is recognized as a biological principle yet the theory of evolution is populational in character and best depicted statistically' (Park 1942, 137).
Park was worried about being misunderstood as a strict adherent to a solely statistical frame of mind. However, one could very well imagine that Park might have resisted the following passage from the introduction of the co-authored text:
'Some few [ecological] relations can be given fairly exact mathematical treatment. There is much room for pure humility among ecologists who are trying to cope with these loosely formulated relationships, most of which cannot be expressed in exact quantitative formulations' (p. 11, emphasis mine).
After all, Park noted that '[t]he distinctive features of the population are correlated with the fact that it is a statistical entity' (1939, 235). In this paper, Park provided a nice categorization of mathematical work already developed in 1939 'in the ecological population field'. He claimed that this work 'fall[s] into three categories: the use of statistical methods, the development of empirical curves to describe the growth of populations and the rationalization of equations that picture inter-species competition' (1939, 237). He then proceeded to highlight the formal work of Gause (e.g., mathematics of inter-species competition – 'competitive exclusion principle'), Lotka and Volterra (mathematics of predator-prey relationships), and Pearl (the Logistic Curve of population growth), among others. Furthermore, he claimed that 'ecology is, to a large degree, a quantitative science: the ultimate problems are group and group-interaction problems. To get at such interactions we must employ quantitative methods.' (1939, 251, emphasis mine). Ultimately, Park is remembered particularly for his elegant experiments showing the indeterminacy and stochasticity of particular species extinctions in multi-species environments of Tribolium (e.g., Simberloff 1980). These experiments fundamentally required statistical and formal techniques. Furthermore, perhaps his most important student, Michael Wade, is also famous for his development of formal theory. Wade's profound knowledge of biology, however, is also testimony to him as a hybrid figure.
Park sought to include both biological and statistical aspects of ecology. This is a noble cause. In the context of the development of formal biology - i.e., population genetics (1920s and subsequently) and theoretical mathematical ecology (1950s and 1960s and subsequently) - it is, and remains, difficult to relate (let alone hybridize) these two styles of analyzing, developing, and testing theory and practice. During the 1950s, and more so during the 1960s, compositional concerns were, to a very important extent, lost from ecology and population biology (but see discussions in Levins & Lewontin 1985), and the goal became the establishment of formal analytical equations. A full exploration of the demise of the compositional style in ecology and in biological social science, a style so strongly endorsed by the Chicago School of Ecology, would require a complementary investigation of the rise of formal ecology, including the role played by Thomas Park and Sewall Wright (for roughly half a page of mathematical population genetic theory written by Wright, see Allee et al. 1949, 649). This is beyond the scope of the current paper.
As a future component of this project, insightful criticisms of the syntheticunificationist biological social science project at Chicago, such as those articulated by Simpson (1941) and Novikoff (1945), and even by allies such as Needham (1945) should be explored. What is of interest with these concerns, in contrast to G.C. Williams' criticisms, for example, is that the former were still wholly within the compositional framework. Neither Simpson nor Novikoff criticized the hierarchical part-whole conception adopted by the Chicago Group. That had changed by the time of Williams (1966).