Abstract
Mutations can alter the short-term fitness of an organism, as well as the rates and benefits of future mutations. While numerous examples of these evolvability modifiers have been observed in rapidly adapting microbial populations, existing theory struggles to predict when they will be favoured by natural selection. Here we develop a mathematical framework for predicting the fates of genetic variants that modify the rates and benefits of future mutations in linked genomic regions. We derive analytical expressions showing how the fixation probabilities of these variants depend on the size of the population and the diversity of competing mutations. We find that competition between linked mutations can dramatically enhance selection for modifiers that increase the benefits of future mutations, even when they impose a strong direct cost on fitness. However, we also find that modest direct benefits can be sufficient to drive evolutionary dead ends to fixation. Our results suggest that subtle differences in evolvability could play an important role in shaping the long-term success of genetic variants in rapidly evolving microbial populations.
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Data availability
Fitness measurements and confidence intervals in Fig. 1a were obtained from the Supplementary Information of ref. 8. Simulation results in the remaining figures are available in the accompanying source data files. Source data are provided with this paper.
Code availability
Source code for forward-time simulations, numerical calculations and figure generation are available via Github (https://github.com/bgoodlab/evolution_of_evolvability).
References
Matic, I. et al. Highly variable mutation rates in commensal and pathogenic Escherichia coli. Science 277, 1833–1834 (1997).
LeClerc, J. E., Li, B., Payne, W. L. & Cebula, T. A. High mutation frequencies among Escherichia coli and Salmonella pathogens. Science 274, 1208–1211 (1996).
Loeb, L. A. Human cancers express mutator phenotypes: origin, consequences and targeting. Nat. Rev. Cancer 11, 450–457 (2011).
Sane, M., Diwan, G. D., Bhat, B. A., Wahl, L. M. & Agashe, D. Shifts in mutation spectra enhance access to beneficial mutations. Proc. Natl Acad. Sci. USA 120, e2207355120 (2023).
Sniegowski, P. D., Gerrish, P. J. & Lenski, R. E. Evolution of high mutation rates in experimental populations of E. coli. Nature 387, 703–705 (1997).
Couce, A., Guelfo, J. R. & Blázquez, J. Mutational spectrum drives the rise of mutator bacteria. PLoS Genet. 9, e1003167 (2013).
Freddolino, P. L., Goodarzi, H. & Tavazoie, S. Fitness landscape transformation through a single amino acid change in the rho terminator. PLoS Genet. 8, e1002744 (2012).
Woods, R. J. et al. Second-order selection for evolvability in a large Escherichia coli population. Science 331, 1433–1436 (2011).
Aggeli, D., Li, Y. & Sherlock, G. Changes in the distribution of fitness effects and adaptive mutational spectra following a single first step towards adaptation. Nat. Commun. 12, 5193 (2021).
Johnson, M. S. et al. Phenotypic and molecular evolution across 10,000 generations in laboratory budding yeast populations. Elife 10, e63910 (2021).
Blount, Z. D., Borland, C. Z. & Lenski, R. E. Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli. Proc. Natl Acad. Sci. USA 105, 7899–7906 (2008).
Palmer, M. E., Moudgil, A. & Feldman, M. W. Long-term evolution is surprisingly predictable in lattice proteins. J. R. Soc. Interface 10, 20130026 (2013).
Barrick, J. E., Kauth, M. R., Strelioff, C. C. & Lenski, R. E. Escherichia coli rpoB mutants have increased evolvability in proportion to their fitness defects. Mol. Biol. Evol. 27, 1338–1347 (2010).
Karlsson, K. et al. Deterministic evolution and stringent selection during preneoplasia. Nature 618, 383–393 (2023).
Colom, B. et al. Mutant clones in normal epithelium outcompete and eliminate emerging tumours. Nature 598, 510–514 (2021).
Fabre, M. A. et al. The longitudinal dynamics and natural history of clonal haematopoiesis. Nature 606, 335–342 (2022).
Gifford, D. R. et al. Identifying and exploiting genes that potentiate the evolution of antibiotic resistance. Nat. Ecol. Evol. 2, 1033–1039 (2018).
Vogwill, T., Kojadinovic, M. & MacLean, R. C. Epistasis between antibiotic resistance mutations and genetic background shape the fitness effect of resistance across species of pseudomonas. Proc. R. Soc. B 283, 20160151 (2016).
Cummins, E. A., Snaith, A. E., McNally, A. & Hall, R. J. The role of potentiating mutations in the evolution of pandemic Escherichia coli clones. Eur. J. Clin. Microbiol. Infect. Dis. https://doi.org/10.1007/s10096-021-04359-3 (2021).
Altenberg, L., Liberman, U. & Feldman, M. W. Unified reduction principle for the evolution of mutation, migration, and recombination. Proc. Natl Acad. Sci. USA 114, E2392–E2400 (2017).
Wagner, G. P. Feedback selection and the evolution of modifiers. Acta Biotheor. 30, 79–102 (1981).
Wilke, C., Wang, J. L., Ofria, C., Lenski, R. E. & Adami, C. Evolution of digital organisms at high mutation rates leads to survival of the flattest. Nature 412, 331–333 (2001).
Payne, J. L. & Wagner, A. The causes of evolvability and their evolution. Nat. Rev. Genet. 20, 24–38 (2019).
Pigliucci, M. Is evolvability evolvable? Nat. Rev. Genet. 9, 75–82 (2008).
Hansen, T. F., Houle, D., Pavličev, M. & Pélabon, C. (eds) Evolvability: A Unifying Concept in Evolutionary Biology? (MIT Press, 2023); https://doi.org/10.7551/mitpress/14126.003.0022
Good, B. H. & Desai, M. M. Evolution of mutation rates in rapidly adapting asexual populations. Genetics 204, 1249–1266 (2016).
van Gestel, J. et al. Short-range quorum sensing controls horizontal gene transfer at micron scale in bacterial communities. Nat. Commun. 12, 2324 (2021).
Raynes, Y., Wylie, C. S., Sniegowski, P. D. & Weinreich, D. M. Sign of selection on mutation rate modifiers depends on population size. Proc. Natl Acad. Sci. USA 115, 3422–3427 (2018).
Tuffaha, M. Z., Varakunan, S., Castellano, D., Gutenkunst, R. N. & Wahl, L. M. Shifts in mutation bias promote mutators by altering the distribution of fitness effects. Am. Nat. 202, 503–518 (2023).
van Nimwegen, E., Crutchfield, J. P. & Huynen, M. Neutral evolution of mutational robustness. Proc. Natl Acad. Sci. USA 96, 9716–9720 (2001).
Lang, G. I. et al. Pervasive genetic hitchhiking and clonal interference in forty evolving yeast populations. Nature 500, 571–574 (2013).
Levy, S. F. et al. Quantitative evolutionary dynamics using high-resolution lineage tracking. Nature 519, 181–186 (2015).
Good, B. H., McDonald, M. J., Barrick, J. E., Lenski, R. E. & Desai, M. M. The dynamics of molecular evolution over 60,000 generations. Nature 551, 45–50 (2017).
Strelkowa, N. & Lässig, M. Clonal interference in the evolution of influenza. Genetics 192, 671–682 (2012).
Zanini, F. et al. Population genomics of intrapatient HIV-1 evolution. Elife 4, e11282 (2015).
Rochman, N. D. et al. Ongoing global and regional adaptive evolution of SARS-CoV-2. Proc. Natl Acad. Sci. USA 118, e2104241118 (2021).
Kemp, S. A. et al. SARS-CoV-2 evolution during treatment of chronic infection. Nature 592, 277–282 (2021).
Barroso-Batista, J. et al. The first steps of adaptation of Escherichia coli to the gut are dominated by soft sweeps. PLoS Genet. 10, e1004182 (2014).
Zhao, S. et al. Adaptive evolution within gut microbiomes of healthy people. Cell Host Microbe 25, 656–667.e8 (2019).
Lieberman, T. D. et al. Genetic variation of a bacterial pathogen within individuals with cystic fibrosis provides a record of selective pressures. Nat. Genet. 46, 82–87 (2014).
Neher, R. A. Genetic draft, selective interference, and population genetics of rapid adaptation. Annu. Rev. Ecol. Evol. Syst. 44, 195–215 (2013).
Good, B. H., Rouzine, I. M., Balick, D. J., Hallatschek, O. & Desai, M. M. Distribution of fixed beneficial mutations and the rate of adaptation in asexual populations. Proc. Natl Acad. Sci. USA 109, 4950–4955 (2012).
Fisher, D. S. Asexual evolution waves: fluctuations and universality. J. Stat. Mech. Theory Exp. 2013, P01011 (2013).
Kryazhimskiy, S., Rice, D. P., Jerison, E. R. & Desai, M. M. Global epistasis makes adaptation predictable despite sequence-level stochasticity. Science 344, 1519–1522 (2014).
Wagner, A. Evolvability-enhancing mutations in the fitness landscapes of an RNA and a protein. Nat. Commun. 14, 3624 (2023).
Barton, N. H. & Etheridge, A. M. The relation between reproductive value and genetic contribution. Genetics 188, 953–973 (2011).
Neher, R. A., Shraiman, B. I. & Fisher, D. S. Rate of adaptation in large sexual populations. Genetics 184, 467–481 (2010).
Birky, C. W. & Walsh, J. B. Effects of linkage on rates of molecular evolution. Proc. Natl Acad. Sci. USA 85, 6414–6418 (1988).
Keightley, P. D. & Otto, S. P. Interference among deleterious mutations favours sex and recombination in finite populations. Nature 443, 89–92 (2006).
Good, B. H. & Desai, M. M. Deleterious passengers in adapting populations. Genetics 198, 1183–1208 (2014).
Desai, M. M. & Fisher, D. S. Beneficial mutation–selection balance and the effect of linkage on positive selection. Genetics 176, 1759–1798 (2007).
Hegreness, M., Shoresh, N., Hartl, D. & Kishony, R. An equivalence principle for the incorporation of favorable mutations in asexual populations. Science 311, 1615–1617 (2006).
Nguyen Ba, A. N. et al. High-resolution lineage tracking reveals travelling wave of adaptation in laboratory yeast. Nature 575, 494–499 (2019).
Karthikeyan, S. et al. Wastewater sequencing reveals early cryptic SARS-CoV-2 variant transmission. Nature 609, 101–108 (2022).
Łuksza, M. & Lässig, M. A predictive fitness model for influenza. Nature 507, 57–61 (2014).
Lee, J. M. et al. Deep mutational scanning of hemagglutinin helps predict evolutionary fates of human H3N2 influenza variants. Proc. Natl Acad. Sci. USA 115, E8276–E8285 (2018).
Łuksza, M. et al. Neoantigen quality predicts immunoediting in survivors of pancreatic cancer. Nature 606, 389–395 (2022).
Wiser, M. J., Ribeck, N. & Lenski, R. E. Long-term dynamics of adaptation in asexual populations. Science 342, 1364–1367 (2013).
Ascensao, J. A., Wetmore, K. M., Good, B. H., Arkin, A. P. & Hallatschek, O. Quantifying the local adaptive landscape of a nascent bacterial community. Nat. Commun. 14, 248 (2023).
Couce, A. et al. Changing fitness effects of mutations through long-term bacterial evolution. Science https://doi.org/10.1126/science.add1417 (2024).
Frenkel, E. M., Good, B. H. & Desai, M. M. The fates of mutant lineages and the distribution of fitness effects of beneficial mutations in laboratory budding yeast populations. Genetics 196, 1217–1226 (2014).
Draghi, J. A., Parsons, T. L., Wagner, G. P. & Plotkin, J. B. Mutational robustness can facilitate adaptation. Nature 463, 353–355 (2010).
Johnson, M. S., Martsul, A., Kryazhimskiy, S. & Desai, M. M. Higher-fitness yeast genotypes are less robust to deleterious mutations. Science 366, 490–493 (2019).
Zheng, J., Guo, N. & Wagner, A. Selection enhances protein evolvability by increasing mutational robustness and foldability. Science 370, eabb5962 (2020).
Sung, W., Ackerman, M. S., Miller, S. F., Doak, T. G. & Lynch, M. Drift-barrier hypothesis and mutation-rate evolution. Proc. Natl Acad. Sci. USA 109, 18 488–18 492 (2012).
Wylie, C. S. & Shakhnovich, E. I. A biophysical protein folding model accounts for most mutational fitness effects in viruses. Proc. Natl Acad. Sci. USA 108, 9916–9921 (2011).
Archetti, M. Survival of the steepest: hypersensitivity to mutations as an adaptation to soft selection. J. Evol. Biol. 22, 740–750 (2009).
Good, B. H. & Desai, M. M. The impact of macroscopic epistasis on long-term evolutionary dynamics. Genetics 199, 177–190 (2015).
Agarwala, A. & Fisher, D. S. Adaptive walks on high-dimensional fitness landscapes and seascapes with distance-dependent statistics. Theor. Popul. Biol. 130, 13–49 (2019).
Hanage, W. P. Not so simple after all: bacteria, their population genetics, and recombination. Cold Spring Harb. Perspect. Biol. 8, a018069 (2016).
Gardner, A. & Kalinka, A. T. Recombination and the evolution of mutational robustness. J. Theor. Biol. 241, 707–715 (2006).
Weissman, D. B. & Hallatschek, O. The rate of adaptation in large sexual populations with linear chromosomes. Genetics 196, 1167–1183 (2014).
Neher, R. A., Kessinger, T. A. & Shraiman, B. I. Coalescence and genetic diversity in sexual populations under selection. Proc. Natl Acad. Sci. USA 110, 15 836–15 841 (2013).
Good, B. H., Walczak, A. M., Neher, R. A. & Desai, M. M. Genetic diversity in the interference selection limit. PLoS Genet. 10, e1004222 (2014).
Dawson, K. J. Evolutionarily stable mutation rates. J. Theor. Biol. 194, 143–157 (1998).
Barnett, M., Zellar, L. & Rainey, P. B. Experimental evolution of evolvability. Preprint at bioRxiv https://www.biorxiv.org/content/early/2024/05/03/2024.05.01.592015 (2024).
Guillaume, F. & Otto, S. P. Gene functional trade-offs and the evolution of pleiotropy. Genetics 192, 1389–1409 (2012).
Lenski, R. E., Rose, M. R., Simpson, S. C. & Tadler, S. C. Long-term experimental evolution in Escherichia coli. I. Adaptation and divergence during 2,000 generations. Am. Nat. 138, 1315–1341 (1991).
Kondrashov, F. A. & Kondrashov, A. S. Multidimensional epistasis and the disadvantage of sex. Proc. Natl Acad. Sci. USA 98, 12 089–12 092 (2001).
Leigh, E. G. The evolution of mutation rates. Genetics 73, Suppl 73:1–18 (1973).
Acknowledgements
We thank D. Wong for useful discussions and S. Walton, O. Ghosh and Z. Liu for comments and feedback on the manuscript. This work was supported in part by the Alfred P. Sloan Foundation (FG-2021-15708) and a Terman Fellowship from Stanford University. B.H.G. is a Chan Zuckerberg Biohub San Francisco Investigator.
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Conceptualization: J.T.F. and B.H.G.; theory and methods development: J.T.F. and B.H.G.; analysis: J.T.F. and B.H.G.; writing: J.T.F. and B.H.G.
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Extended data
Extended Data Fig. 1 Examples of epistatic fitness landscapes that satisfy the minimal model in Fig. 1.
(a) The evolvability modifier in Fig. 1b can be viewed as the lowest order term in a general macroscopic epistasis expansion (left, SI Section 3.1). Different fitness landscapes can produce the same macroscopic behavior. (b,c) Examples of highly epistatic fitness landscapes that satisfy the simple model above. (b) A ‘maximally epistatic’ landscape of branching uphill paths, which generalizes the model in refs. 79,80. Each step k = 1, …, K of a given path can access M ≪ L beneficial mutations; all other genotypes have fitness zero. (c) A fitness landscape formed by a non-linear combination of two global phenotypes, for example, stability, \(\Phi (\,{\overrightarrow{g}})\), and activity, \(\Psi (\,{\overrightarrow{g}})\). Individual mutations can affect both traits simultaneously (right). Stabilizing mutations can act like modifier alleles by potentiating the fitness benefits of mutations that would destabilize the protein on their own (left). In particular, a strongly stabilizing mutation can allow K ≈ ϕm/∣ϕℓ∣ new mutations to accumulate before their effects on stability become important. See SI Section 3.1 for more details.
Extended Data Fig. 2 Deleterious mutations and indirect selection for robustness.
(a) A generalization of the simplified model in Fig. 5a, where the modifier can also shift the typical fitness cost sd. (b, c) Fixation probability of a robustness-enhancing modifier with \({U}_{d}^{{\prime} } < {U}_{d}\) (and all other parameters are held fixed). Symbols denote the results of forward time simulations for N = 108, sb = 10−2, and Ub = 10−5, while solid lines denote our theoretical predictions in SI Section 6. Panel (b) shows that the purgeable mutations approximation holds across a broad range of fitness costs, with the dashed line marking the predicted transition to quasi-neutrality (∣sd∣ ≈ v/xc). Panel (c) shows that selection for increased robustness is relatively weak unless Ud ≳ sb (dashed line). (d) Fixation probability of a modifier that imposes a tradeoff between robustness and evolvability by increasing the strength of selection on beneficial and deleterious mutations simultaneously. Results are shown for sb = ∣sd∣ = s and Ud = 10−2, with the remaining parameters the same as panel b. Since Ud ≫ Ub, this example shows that strong selection for evolvability can occur for modifiers reduce the average fitness effect of mutations (\(\Delta \overline{s}\propto {U}_{b}\Delta s-{U}_{d}\Delta s < 0\)). (e) Fixation probability of modifier that enhances robustness and evolvability at the same, by shifting mutations from deleterious to beneficial \(({U}_{d}-{U}_{d}^{{\prime} }={U}_{b}^{{\prime} }-{U}_{b})\). Symbols denote results of forward-time simulations with sd = − 10−2 and Ud = 10−2, with the remaining parameters the same as panel (b). Lines denote our theoretical predictions in the absence of deleterious mutations (\({U}_{d}={U}_{d}^{{\prime} }=0\)). This example shows that enhancements in evolvability are weighted more strongly than comparable increases in robustness, even when nearly all new mutations are deleterious (Ub ≪ Ud).
Extended Data Fig. 3 Relaxing the assumption that modifiers permanently change the mutation spectrum.
An alternative version of the model in Fig. 5c, where the modifier reverts to an evolutionary dead-end (μm(s) = 0) after K mutations. Symbols denote the results of forward-time simulations for N = 108, sb = 10−2, and Ub = 10−5, while the line denotes our theoretical predictions for the minimal modifier model in Fig. 1b (that is K = ∞). Even in this extreme case, our minimal modifier model (solid line) remains highly accurate for moderate values of K, and as little as K = 1 in the quasi-sweeps regime. This demonstrates that large populations can only ‘see’ across the fitness landscape for \(\approx {x}_{cm}/{s}_{b}^{{\prime} }\) additional mutations (SI Section 7.2).
Extended Data Fig. 4 Selection for evolvability in the presence of diminishing returns epistasis.
(a, b) A simple model of global diminishing returns epistasis motivated by the empirical example in ref. 58 (SI Section 7.3). The fitness effects of new mutations shrink as the population adapts (panel a), leading to a decelerating rate of adaptation over time (panel b). Points denote the results of forward-time simulations for the distribution of fitness effects \(\mu (s|\overrightarrow{g})={U}_{b}\cdot \delta (s-{\tilde{s}}_{b}\cdot {e}^{-X(\overrightarrow{g})/\theta })\), with Ub = 10−5, \({\tilde{s}}_{b}=1{0}^{-1}\), θ = 0.2, and N = 107; points are connected by solid lines to aid visualization. (c, d) The fixation probability of an evolvability modifier that arises at the beginning of the inset in panel a, where the fitness trajectory is still decelerating. Green symbols in (c) show a selection-strength modifier with the same diminishing returns schedule as the background population (θm ≈ θ), while the blue symbols show an alternate example where the modifier avoids future diminishing returns once it arises (θm ≈ ∞). The green line illustrates the predictions from the ‘adiabatic’ approximation in SI Section 7.3, demonstrating that the permanent modifier model [\({\mu }_{m}(s|\overrightarrow{g})\approx {\mu }_{m}(s)\)] provides a good approximation when the local selection strengths are properly renormalized. The blue line shows the predictions from our heuristic analysis in SI Section 7.3, which accounts for the additional benefits that accrue for the modifier lineage when θm ≫ θ (panel d). This example illustrates that the evolvability advantages that accrue from large differences in diminishing returns epistasis can drive modest deviations from our existing theory when θ grows close to xc.
Supplementary information
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Supplementary Sections 1–8.
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Ferrare, J.T., Good, B.H. Evolution of evolvability in rapidly adapting populations. Nat Ecol Evol (2024). https://doi.org/10.1038/s41559-024-02527-0
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DOI: https://doi.org/10.1038/s41559-024-02527-0