Spatiotemporal ecological chaos enables gradual evolutionary diversification without niches or tradeoffs

  1. Aditya Mahadevan
  2. Michael T Pearce
  3. Daniel S Fisher  Is a corresponding author
  1. Stanford University, United States
  2. Meta Data Science, United States

Abstract

Ecological and evolutionary dynamics are intrinsically entwined. On short timescales, ecological interactions determine the fate and impact of new mutants, while on longer timescales evolution shapes the entire community. Here we study the evolution of large numbers of closely related strains with generalized Lotka Volterra interactions but no niche structure. Host-pathogen-like interactions drive the community into a spatiotemporally chaotic state characterized by continual, spatially-local, blooms and busts. Upon the slow serial introduction of new strains, the community diversifies indefinitely, accommodating an arbitrarily large number of strains in spite of the absence of stabilizing niche interactions. The diversifying phase persists - albeit with gradually slowing diversification - in the presence of general, nonspecific, fitness differences between strains, which break the assumption of tradeoffs inherent in much previous work. Building on a dynamical-mean field-theory analysis of the ecological dynamics, an approximate effective model captures the evolution of the diversity and distributions of key properties. This work establishes a potential scenario for understanding how the interplay between evolution and ecology - in particular coevolution of a bacterial and a generalist phage species - could give rise to the extensive fine-scale diversity that is ubiquitous in the microbial world.

Data availability

The current manuscript is a computational study, so no data have been generated for this manuscript. Simulations use only standard algorithms: details in paper.

Article and author information

Author details

  1. Aditya Mahadevan

    Department of Physics, Stanford University, Stanford, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Michael T Pearce

    Meta Data Science, Menlo Park, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Daniel S Fisher

    Department of Physics, Stanford University, Stanford, United States
    For correspondence
    dsfisher@stanford.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5559-2491

Funding

National Science Foundation (PHY-160760 and PHY-2210386)

  • Aditya Mahadevan
  • Michael T Pearce
  • Daniel S Fisher

National Institutes of Health (R01AI13699201)

  • Aditya Mahadevan
  • Daniel S Fisher

Simons Foundation (Sabbatical Fellowship)

  • Daniel S Fisher

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Armita Nourmohammad, University of Washington, United States

Version history

  1. Preprint posted: May 28, 2022 (view preprint)
  2. Received: August 16, 2022
  3. Accepted: April 27, 2023
  4. Accepted Manuscript published: April 28, 2023 (version 1)
  5. Version of Record published: June 28, 2023 (version 2)

Copyright

© 2023, Mahadevan et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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  1. Aditya Mahadevan
  2. Michael T Pearce
  3. Daniel S Fisher
(2023)
Spatiotemporal ecological chaos enables gradual evolutionary diversification without niches or tradeoffs
eLife 12:e82734.
https://doi.org/10.7554/eLife.82734

Share this article

https://doi.org/10.7554/eLife.82734

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