Adaptation and evolutionary theory

The early history of chance in evolution

“…Precisely the same worry about the relationship between statistical theories and biological processes has been hotly debated, under the guise of the "causalist/statisticalist debate." On the one side, we have "causalists," who argue that natural selection and genetic drift describe causally efficacious processes (e.g., Brandon, 1978;Mills and Beatty, 1979;Hodge, 1987;Stephens, 2004;Ramsey, 2006;Abrams, 2009;Otsuka et al, 2011). They are opposed by the "statisticalists," who claim on the contrary that these theories are merely statistical summaries of genuinely causal events at the level of the individual organism (e.g., Matthen and Ariew, 2002;Walsh et al, 2002;Ariew and Lewontin, 2004;Krimbas, 2004;Walsh, 2007;Ariew and Ernst, 2009;Walsh, 2010).…”

“…The second question is explored by Morizot (2012). Philosophically, many works -such as Brandon andCarson (1996), Millstein (2000), Rosenberg (2001), or Pence and Ramsey (2013) -implicitly rely on this distinction between the (assumed) statistical nature of evolutionary theory and the (contested) "chanciness" of biological processes. genuine, objective sense was utilized (i.e., the first use of one particular philosophical conception of chance)?…”

A critical review of the statisticalist debate

“…Whether fitness is and should be based on causal properties of organisms is an old problem in the philosophy of biology, often debated under the heading of the propensity interpretation of fitness (Brandon, 1978;Brandon and Ramsey, 2007;Mills and Beatty, 1979;Sober, 1984Sober, , 2001Sober, , 2013Rosenberg, 1985;Ariew and Ernst, 2009;Pence and Ramsey, 2013). This labeling, however, may blur rather than reveal what is at issue, for historically the "propensity interpretation" has been used by different authors to denote different theses, to name a few (i) that fitness denotes a propensity or capacity of an organism to survival and reproduce, rather than its actual performance; (ii) that fitness should be defined by the statistical expectation, rather than a sample moment; (iii) that fitness is caused by organismal phenotype; and (iv) that for any fitness function there is a scalar value that summarizes the direction of the adaptive response.…”

Fitness: Philosophical Problems

“…The propensity interpretation of fitness (PIF) was introduced in the late 1970s by Brandon (1978) and Mills and Beatty (1979). They argued that instead of considering the fitness of organisms to be identified with the actual number of offspring produced, fitness should instead be equated with the probabilistic propensity to produce offspring-a distribution of probability values describing how likely it is that an organism will produce no offspring, one offspring, etc.…”