The end of the adaptive landscape metaphor?

Abstract

The concepts of adaptive/fitness landscapes and adaptive peaks are a central part of much of contemporary evolutionary biology; the concepts are introduced in introductory texts, developed in more detail in graduate-level treatments, and are used extensively in papers published in the major journals in the field. The appeal of visualizing the process of evolution in terms of the movement of populations on such landscapes is very strong; as one becomes familiar with the metaphor, one often develops the feeling that it is possible to gain deep insights into evolution by thinking about the movement of populations on landscapes consisting of adaptive valleys and peaks. But, since Wright first introduced the metaphor in 1932, the metaphor has been the subject of persistent confusion, from equivocation over just what the features of the landscape are meant to represent to how we ought to expect the landscapes to look. Recent advances-conceptual, empirical, and computational-have pointed towards the inadequacy and indeed incoherence of the landscapes as usually pictured. I argue that attempts to reform the metaphor are misguided; it is time to give up the pictorial metaphor of the landscape entirely and rely instead on the results of formal modeling, however difficult such results are to understand in 'intuitive' terms.

Adaptive landscapes and protein evolution

“…Another thoughtful observer has recommended that it "is time to give up the pictorial metaphor of the landscape entirely" (29). Wright himself seemed momentarily to have misgivings.…”

Embodied artificial life at an impasse can evolutionary robotics methods be scaled?

“…Human cognition, intuition and linguistic issues may play a significant role in introducing methodological and theoretical difficulties into the design of goal-driven artificial evolutionary systems [15,16,25,74]. For example, [15] points out that there is little evidence or theory to connect evolutionary processes to increasing complexity, but that this concept remains a fixture in descriptions of natural selection.…”

Landscapes, Surfaces, and Morphospaces: What Are They Good For?

“…Indeed, an argument can be made that entire research programs, such as the search for mechanisms causing "peak shifts," have been informed by a faulty assumption, since more realistic hyperdimensional genotypic spaces simply do not have anything that resembles peaks and valleys. It seems like the rational thing to do in this case would in fact be to follow Kaplan's (2008) advice, abandon the metaphor altogether and simply embrace directly the results of formal modeling-as both the cases of Gavrilets' "holey" spaces and the research on the evolution of RNA and protein function elegantly illustrate. Wright may have needed to soften his math with pictures in the 1930s, but surely modern biologists ought to be able to take on the full force of the mathematical theory of evolution.…”

“…Work by Gavrilets (2003; this volume) and collaborators, made possible by the availability of computing power exceeding by several orders of magnitudes what was achievable throughout the twentieth century, has explored the features of truly highly dimensional landscapes-as opposed to the standard two-or three-dimensional ones explicitly considered by Wright and by most previous authors. As it turns out, evolution on so-called "holey" landscapes is characterized by qualitatively different dynamics from those suggested by the standard low-dimensional version of the metaphor-a conclusion that has led some authors to suggest abandoning the metaphor altogether, in favor of embracing directly the results of formal modeling (Kaplan 2008; though see Plutynski 2008 and Chapter 2 for a somewhat different take).…”