Much philosophical progress has been made in elucidating the idea of evolutionary contingency in a recent re-burgeoning of the debate. However, additional progress has been impaired on three fronts. The first relates to its characterisation: the under-specification of various contingency claims has made it difficult to conceptually pinpoint the scope to which ‘contingency’ allegedly extends, as well as which biological forms are in contention. That is—there appears to be no systematic means with which to fully specify contingency claims which has (...) led to a tendency for authors to talk past each other. Secondly, on the matter of evidence, recent research has focused on the evidential import of convergent evolution which is taken to disconfirm the evolutionary contingency thesis. However, there has been a neglect of convergent evolution’s converse: ‘evolutionary idiosyncrasies’ or the singular evolution of certain forms, which I argue is evidentially supportive of evolutionary contingency. Thirdly, evolutionary contingency has often been claimed to vary in degrees and that the debate, itself, is a matter of ‘relative significance’. However, there has been no formal method of evaluating the strength of contingency and its relative significance in a particular domain. In this paper, I address all three issues by proposing a systematic means of fully specifying contingency theses with the concept of the modal range. Secondly, I propose an account of evolutionary idiosyncrasies, investigate the explanations for their occurrences, and, subsequently, spell out their significance with respect to the evolutionary contingency thesis. Finally, having been equipped with the evidential counterpart to convergent evolution, I shall sketch a likelihood framework for evaluating, precisely on the basis of a sequence of opposing data, the strength and relative significance of evolutionary contingency in a particular domain. With this in hand, the relative observations of idiosyncrasies and convergences can be informative of the strength and relative significance of contingency in any particular domain. (shrink)

Stephen Jay Gould argued that replaying the “tape of life” would result in a radically different evolutionary outcome. Some biologists and philosophers, however, have pointed to convergent evolution as evidence for robust replicability in macroevolution. These authors interpret homoplasy, or the independent origination of similar biological forms, as evidence for the power of natural selection to guide form toward certain morphological attractors, notwithstanding the diversionary tendencies of drift and the constraints of phylogenetic inertia. In this paper, I consider the implications (...) of homoplasy for the debate over the nature of macroevolution. I argue that once the concepts of contingency and convergence are fleshed out, it becomes clear that many instances of homoplasy fail to negate Gould’s overarching thesis, and may in fact support a Gouldian view of life. My argument rests on the distinction between parallelism and convergence, which I defend against a recent challenge from developmental biology. I conclude that despite the difficulties in defining and identifying parallelism, the concept remains useful and relevant to the contingency controversy insofar as it underscores the common developmental origins of iterated evolution. (shrink)

Researchers in the life sciences often make uniqueness attributions; about branching events generating new species, the developmental processes generating novel traits and the distinctive cultural selection pressures faced by hominins. Yet since uniqueness implies non-recurrence, such attributions come freighted with epistemic consequences. Drawing on the work of Aviezer Tucker, we show that a common reaction to uniqueness attributions is pessimism: both about the strength of candidate explanations as well as the ability to even generate such explanations. Looking at two case (...) studies—elephant trunks and human teaching—we develop a more optimistic account. As we argue, uniqueness attributions are revisable claims about the availability of several different kinds of comparators. Yet even as researchers investigate the availability of such comparators, they are able to mobilize complex sets of empirical and theoretical tools. Rather than hindering scientific investigation, then, we argue that uniqueness attributions often spur the generation of a range of epistemic goods. (shrink)

I develop an account of homology and homoplasy drawing on their use in biological inference and explanation. Biologists call on homology and homoplasy to infer character states, support adaptationist explanations, identify evolutionary novelties and hypothesize phylogenetic relationships. In these contexts, the concepts must be understood phylogenetically and kept separate: as they play divergent roles, overlap between the two ought to be avoided. I use these considerations to criticize an otherwise attractive view defended by Gould, Hall, and Ramsey & Peterson. By (...) this view, homology and homoplasy can only be delineated qua some level of description, and some homoplasies (parallelisms) are counted as homologous. I develop an account which retains the first, but rejects the second, aspect of that view. I then characterize parallelisms and convergences in terms of their causal role. By the Strict Continuity account, homology and homoplasy are defined phylogenetically and without overlaps, meeting my restriction. Convergence and parallelisms are defined as two types of homoplasy: convergent homoplasies are largely constrained by external factors, while parallelisms are due to internal constraints. (shrink)

Ethnographic analogy, the use of comparative data from anthropology to inform reconstructions of past human societies, has a troubled history. Archaeologists often express concern about, or outright reject, the practice—and sometimes do so in problematically general terms. This is odd, as the use of comparative data in archaeology is the same pattern of reasoning as the ‘comparative method’ in biology, which is a well-developed and robust set of inferences which play a central role in discovering the biological past. In pointing (...) out this continuity, I argue that there is no ‘special pleading’ on the part of archaeologists in this regard: biologists must overcome analogous epistemic difficulties in their use of comparative data. I then go on to emphasize the local, empirically tractable ways in which particular ethnographic analogies may be licensed. (shrink)

The Abrahamic traditions regard God as the world’s author. But what kind of author? A novelist? A playwright? Perhaps a composer of classical music? I will argue that it is best to regard God as like an improvisational play director or the leader of a jazz ensemble. Each determines the broad melodic contours or coarse-grained plot beforehand, while allowing their musicians or actors, and chance, to fill in the more fine-grained details. This analogy allows us to regard God as the (...) ultimate author of this world, while allowing us to be, while less than co-authors, more than mere enactors of a pre-written piece. These metaphors are particularly well-suited to illustrate and flesh out an Open Theistic view of things. (shrink)