Laplace's demon in biology: Models of evolutionary prediction

Abstract

Our ability to predict natural phenomena can be limited by incomplete information. This issue is exemplified by “Laplace's demon,” an imaginary creature proposed in the 18th century, who knew everything about everything, and thus could predict the full nature of the universe forward or backward in time. Quantum mechanics, among other things, has cast doubt on the possibility of Laplace's demon in the full sense, but the idea still serves as a useful metaphor for thinking about the extent to which prediction is limited by incomplete information on deterministic processes versus random factors. Here, we use simple analytical models and computer simulations to illustrate how data limits can be captured in a Bayesian framework, and how they influence our ability to predict evolution. We show how uncertainty in measurements of natural selection, or low predictability of external environmental factors affecting selection, can greatly reduce predictive power, often swamping the influence of intrinsic randomness caused by genetic drift. Thus, more accurate knowledge concerning the causes and action of natural selection is key to improving prediction. Fortunately, our analyses and simulations show quantitatively that reasonable improvements in data quantity and quality can meaningfully increase predictability.

Replicated Evolution in Plants

“…Our examination of replicated evolution in plants suggests several avenues of research that can shed light on how similarity arises in nature. Major lines of inquiry are how predictable evolution can be and at what levels of biological organization it arises (2,21,74,75,124,137). Answering these questions requires new mechanistic models to explain the flow of information from alleles to traits and from traits to ensembles of species, while considering how constraints shape evolution at different biological scales (120, 124,193).…”

Be careful what you wish for: Acceptance of Laplacean Determinism commits one to belief in precognition.

“…Accordingly, it will be the focus of discussion.However, it is worth noting—if only in broad brush strokes—some of the main differences between physical determinism and other causal determinist theories (Herein, I describe a few well-known variants. For fuller discussion, see Allen, 1984; Berofsky, 1971; Dray, 1957, 2008; Earman, 1986; Gompert et al, 2022; Grünbaum, 1956; Kronfeldner, 2009; Sappington, 1990; Solomon & Higgins, 2009; Vicens & Furlong, 2022; Weintraub, 1995; White, 2019; Wilson, 1975). Biological determinism is the belief that human behavior is fully governed by an individual’s genetic endowment (or other components of his or her physiology).…”