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.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
Some authors have suggested distinguishing between adaptive landscapes and fitness landscapes in the following way: adaptive landscapes represent each population as a single point on the landscape (representing either allelic or genotype frequencies in the population as a whole), with axes representing frequencies of alleles or genotypes, whereas fitness landscapes represent each unique genotype as a point on the landscape, with axes representing particular loci. In such fitness landscapes, populations are collections of points whose locations represents genetic distance from each other. As will become clear, I think this distinction is becoming moot, but will follow it nonetheless.
This of course does not hold if every locus is at Hardy–Weinberg equilibrium; however, complete H–W equilibrium is not generally expected in real populations.
In this, he broadly follows Cartwright’s position as expressed in The Dappled World (1999).
If L is the number of loci, and A is the number of alleles, then for haploid organisms, the number of one-step neighbors for each genotype is equal to L(A - 1); for diploid organisms, the number of one-step neighbors is 2L(A − 1).
But note that the probability that an arbitrarily chosen genotype will be of high-fitness is in part an empirical question, and in part depends on difficult-to-interpret background assumptions regarding development and the structure of “genotype space”; more on this topic below.
Nor should an image attempt to capture every aspect of the model; this is related to the uselessness of a one-to-one full-scale “map”.
References
Cartwright N (1999) The dappled world: a study of the boundaries of science. Cambridge University Press, Cambridge
Chang H (2004) Inventing temperature: measurement and scientific progress. Oxford University Press, New York
Gavrilets S (1997) Evolution and speciation on holey adaptive landscapes. Trends Ecol Evol 12(8):307–213
Gavrilets S (2004) Fitness landscapes and the origin of species. Princeton University Press, Princeton
Johnson M, Stinchcombe J (2007) An emerging synthesis between community ecology and evolutionary biology. Trends Ecol Evol 22(5):250–257
Lewontin RC (1978) Adaptation. Sci Am 239:213–230
Pearson H (2006) Genetics: what is a gene? Nature 441:398–401
Provine WB (1986) Sewall Wright and evolutionary biology. University of Chicago Press, Chicago
Ruse M (1996) Are pictures really necessary? The case of Sewall Wright’s ‘adaptive landscapes’. In: Baigrie BS (ed) Picturing knowledge: historical and philosophical programs concerning the use of art in science. University of Toronto Press, Toronto, Canada, pp 303–337
Skipper RA (2004) The heuristic role of Sewall Wright’s 1932 adaptive landscape diagram. Philos Sci 71:1176–1188
Stotz K, Griffiths P (2004) Genes: philosophical analyses put to the test. Hist Philos Life Sci 26:5–28
Wright S (1988) Surfaces of selective value revisited. Am Nat 131:115–123
Wright S (1931) Evolution in mendelian populations. Genetics 16:97–159
Wright S (1932) The roles of mutation, inbreeding, crossbreeding, and selection in evolution. In: The sixth international congress of genetics, vol I, pp 356–366
Acknowledgments
This paper is based in part on a book chapter co-written with Massimo Pigliucci (SUNY Stonybrook). Sergey Gavrilets was generous with his time in providing assistance in understanding his models and approaches. Massimo provided helpful feedback on earlier versions of this material, as did Sharyn Clough, Anya Plutynski, members of the UBC Philosophy Department, Department of Botany, and Department of Zoology, members of the University of Houston’s Department of Biology and Biochemistry, and participants in the 2006 Pacific APA mini-conference “Scientific Images.”
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Kaplan, J. The end of the adaptive landscape metaphor?. Biol Philos 23, 625–638 (2008). https://doi.org/10.1007/s10539-008-9116-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10539-008-9116-z