1
|
Devadhasan A, Kolodny O, Carja O. Competition for resources can reshape the evolutionary properties of spatial structure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.13.589370. [PMID: 38659847 PMCID: PMC11042312 DOI: 10.1101/2024.04.13.589370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Many evolving ecosystems have spatial structures that can be conceptualized as networks, with nodes representing individuals or homogeneous subpopulations and links the patterns of interaction and replacement between them. Prior models of evolution on networks do not take ecological niche differences and eco-evolutionary interplay into account. Here, we combine a resource competition model with evolutionary graph theory to study how heterogeneous topological structure shapes evolutionary dynamics under global frequency-dependent ecological interactions. We find that the addition of ecological competition for resources can produce a reversal of roles between amplifier and suppressor networks for deleterious mutants entering the population. Moreover, we show that this effect is a non-linear function of ecological niche overlap and discuss intuition for the observed dynamics using simulations and analytical approximations.
Collapse
Affiliation(s)
- Anush Devadhasan
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| | - Oren Kolodny
- Department of Ecology, Evolution, and Behavior, E. Silberman Institute of Life Sciences, The Hebrew University of Jerusalem
| | - Oana Carja
- Computational Biology Department, School of Computer Science, Carnegie Mellon University, Pittsburgh, PA, USA
| |
Collapse
|
2
|
Kilner CL, Carrell AA, Wieczynski DJ, Votzke S, DeWitt K, Yammine A, Shaw J, Pelletier DA, Weston DJ, Gibert JP. Temperature and CO 2 interactively drive shifts in the compositional and functional structure of peatland protist communities. GLOBAL CHANGE BIOLOGY 2024; 30:e17203. [PMID: 38433341 DOI: 10.1111/gcb.17203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/20/2024] [Accepted: 01/26/2024] [Indexed: 03/05/2024]
Abstract
Microbes affect the global carbon cycle that influences climate change and are in turn influenced by environmental change. Here, we use data from a long-term whole-ecosystem warming experiment at a boreal peatland to answer how temperature and CO2 jointly influence communities of abundant, diverse, yet poorly understood, non-fungi microbial Eukaryotes (protists). These microbes influence ecosystem function directly through photosynthesis and respiration, and indirectly, through predation on decomposers (bacteria and fungi). Using a combination of high-throughput fluid imaging and 18S amplicon sequencing, we report large climate-induced, community-wide shifts in the community functional composition of these microbes (size, shape, and metabolism) that could alter overall function in peatlands. Importantly, we demonstrate a taxonomic convergence but a functional divergence in response to warming and elevated CO2 with most environmental responses being contingent on organismal size: warming effects on functional composition are reversed by elevated CO2 and amplified in larger microbes but not smaller ones. These findings show how the interactive effects of warming and rising CO2 levels could alter the structure and function of peatland microbial food webs-a fragile ecosystem that stores upwards of 25% of all terrestrial carbon and is increasingly threatened by human exploitation.
Collapse
Affiliation(s)
- Christopher L Kilner
- Department of Biology, Duke University, Durham, North Carolina, USA
- Bird Conservancy of the Rockies, Fort Collins, Colorado, USA
| | - Alyssa A Carrell
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | | | - Samantha Votzke
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Katrina DeWitt
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Andrea Yammine
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Jonathan Shaw
- Department of Biology, Duke University, Durham, North Carolina, USA
| | - Dale A Pelletier
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - David J Weston
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Jean P Gibert
- Department of Biology, Duke University, Durham, North Carolina, USA
| |
Collapse
|
3
|
Corbett JJ, Trussell GC. Local adaptation in trait-mediated trophic cascades. Proc Biol Sci 2024; 291:20232583. [PMID: 38196361 PMCID: PMC10777162 DOI: 10.1098/rspb.2023.2583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 12/04/2023] [Indexed: 01/11/2024] Open
Abstract
Predator-induced changes in prey foraging can influence community dynamics by increasing the abundance of basal resources via a trait-mediated trophic cascade. The strength of these cascades may be altered by eco-evolutionary relationships between predators and prey, but the role of basal resources has received limited attention. We hypothesized that trait-mediated trophic cascade strength may be shaped by selection from trophic levels above and below prey. Field and laboratory experiments used snails (Nucella lapillus) from two regions in the Gulf of Maine (GoM) that vary in basal resource availability (e.g. mussels), seawater temperature, and contact history with the invasive green crab, Carcinus maenas. In field and laboratory experiments, Nucella from both regions foraged on mussels in the presence or absence of green crab risk cues. In the field, Nucella from the northern GoM, where mussels are scarce, were less responsive to risk cues and more responsive to seawater temperature than southern Nucella. In the lab, however, northern Nucella foraged and grew more than southern snails in the presence of risk, but foraging and growth were similar in the absence of risk. We suggest that adaptation to basal resource availability may shape geographical variation in the strength of trait-mediated trophic cascades.
Collapse
Affiliation(s)
- James J. Corbett
- Department of Marine and Environmental Sciences and Coastal Sustainability Institute, Northeastern University, Nahant, MA 01908, USA
| | - Geoffrey C. Trussell
- Department of Marine and Environmental Sciences and Coastal Sustainability Institute, Northeastern University, Nahant, MA 01908, USA
| |
Collapse
|
4
|
Senthilnathan A. Smaller is better in competition for space. Proc Biol Sci 2023; 290:20230627. [PMID: 37339738 PMCID: PMC10281802 DOI: 10.1098/rspb.2023.0627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/19/2023] [Indexed: 06/22/2023] Open
Abstract
Body size is a prominent morphological trait which affects many aspects of an organism's life. Although large body size is generally considered to be advantageous, ecologists have wondered about the benefits of being small. Many studies of body size depend on the metabolic theory of ecology since body size is an irremovable part of an organism's energy budget. Body size is also a spatial quantity and therefore is linked to spatial processes. Here, I show that competition for space leads to a benefit of being small and hence selects for increasingly smaller body size. I build a deterministic population dynamics model and a stochastic model of birth, death and dispersal in a population of individuals with two different body sizes and show that only the smaller individuals survive. I also extend the population dynamics model to continuously varying body sizes and include a stabilizing natural selection for an intermediate body size. I find that the intrinsic advantage of smaller body size in competition for space can only be overcome when natural selection for a large body size is sufficiently strong. Overall, my results point to a novel benefit of being small.
Collapse
|
5
|
DeLong JP, Cressler CE. Stochasticity directs adaptive evolution toward nonequilibrium evolutionary attractors. Ecology 2023; 104:e3873. [PMID: 36116067 PMCID: PMC10078373 DOI: 10.1002/ecy.3873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 08/03/2022] [Indexed: 02/01/2023]
Abstract
Stochastic processes such as genetic drift may hinder adaptation, but the effect of such stochasticity on evolution via its effect on ecological dynamics is poorly understood. Here we evaluate patterns of adaptation in a population subject to variation in demographic stochasticity. We show that stochasticity can alter population dynamics and lead to evolutionary outcomes that are not predicted by classic eco-evolutionary modeling approaches. We also show, however, that these outcomes are governed by nonequilibrium evolutionary attractors-these are maxima in lifetime reproductive success when stochasticity keeps the ecological system away from the deterministic equilibrium. These NEEAs alter the path of evolution but are not visible through the equilibrium lens that underlies much evolutionary theory. Our results reveal that considering population processes during transient periods can greatly improve our understanding of the path and pace of evolution.
Collapse
Affiliation(s)
- John P DeLong
- School of Biological Sciences, University of Nebraska - Lincoln, Lincoln, Nebraska, USA
| | - Clayton E Cressler
- School of Biological Sciences, University of Nebraska - Lincoln, Lincoln, Nebraska, USA
| |
Collapse
|
6
|
Peller T, Guichard F, Altermatt F. The significance of partial migration for food web and ecosystem dynamics. Ecol Lett 2023; 26:3-22. [PMID: 36443028 DOI: 10.1111/ele.14143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 10/09/2022] [Accepted: 10/30/2022] [Indexed: 11/30/2022]
Abstract
Migration is ubiquitous and can strongly shape food webs and ecosystems. Less familiar, however, is that the majority of life cycle, seasonal and diel migrations in nature are partial migrations: only a fraction of the population migrates while the other individuals remain in their resident ecosystem. Here, we demonstrate different impacts of partial migration rendering it fundamental to our understanding of the significance of migration for food web and ecosystem dynamics. First, partial migration affects the spatiotemporal distribution of individuals and the food web and ecosystem-level processes they drive differently than expected under full migration. Second, whether an individual migrates or not is regularly correlated with morphological, physiological, and/or behavioural traits that shape its food-web and ecosystem-level impacts. Third, food web and ecosystem dynamics can drive the fraction of the population migrating, enabling the potential for feedbacks between the causes and consequences of migration within and across ecosystems. These impacts, individually and in combination, can yield unintuitive effects of migration and drive the dynamics, diversity and functions of ecosystems. By presenting the first full integration of partial migration and trophic (meta-)community and (meta-)ecosystem ecology, we provide a roadmap for studying how migration affects and is affected by ecosystem dynamics in a changing world.
Collapse
Affiliation(s)
- Tianna Peller
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland.,Eawag: Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| | | | - Florian Altermatt
- Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland.,Eawag: Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, Switzerland
| |
Collapse
|
7
|
Baker HK, Li SS, Samu SC, Jones NT, Symons CC, Shurin JB. Prey naiveté alters the balance of consumptive and non‐consumptive predator effects and shapes trophic cascades in freshwater plankton. OIKOS 2022. [DOI: 10.1111/oik.09173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Henry K. Baker
- Section of Ecology, Behavior and Evolution, Univ. of California San Diego CA USA
| | - Stephanie S. Li
- Section of Ecology, Behavior and Evolution, Univ. of California San Diego CA USA
- School of Environment and Natural Resources, The Ohio State Univ. Columbus OH USA
| | - Stefan C. Samu
- Section of Ecology, Behavior and Evolution, Univ. of California San Diego CA USA
| | - Natalie T. Jones
- Section of Ecology, Behavior and Evolution, Univ. of California San Diego CA USA
- School of Biological Sciences, Univ. of Queensland St. Lucia QLD Australia
| | - Celia C. Symons
- Dept of Ecology and Evolutionary Biology, Univ. of California Irvine CA USA
| | - Jonathan B. Shurin
- Section of Ecology, Behavior and Evolution, Univ. of California San Diego CA USA
| |
Collapse
|
8
|
Luhring TM, DeLong JP. Trophic cascades alter eco-evolutionary dynamics and body size evolution. Proc Biol Sci 2020; 287:20200526. [PMID: 33143578 DOI: 10.1098/rspb.2020.0526] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Trait evolution in predator-prey systems can feed back to the dynamics of interacting species as well as cascade to impact the dynamics of indirectly linked species (eco-evolutionary trophic cascades; EETCs). A key mediator of trophic cascades is body mass, as it both strongly influences and evolves in response to predator-prey interactions. Here, we use Gillespie eco-evolutionary models to explore EETCs resulting from top predator loss and mediated by body mass evolution. Our four-trophic-level food chain model uses allometric scaling to link body mass to different functions (ecological pleiotropy) and is realistically parameterized from the FORAGE database to mimic the parameter space of a typical freshwater system. To track real-time changes in selective pressures, we also calculated fitness gradients for each trophic level. As predicted, top predator loss generated alternating shifts in abundance across trophic levels, and, depending on the nature and strength in changes to fitness gradients, also altered trajectories of body mass evolution. Although more distantly linked, changes in the abundance of top predators still affected the eco-evolutionary dynamics of the basal producers, in part because of their relatively short generation times. Overall, our results suggest that impacts on top predators can set off transient EETCs with the potential for widespread indirect impacts on food webs.
Collapse
Affiliation(s)
- Thomas M Luhring
- School of Biological Sciences, University of Nebraska, 410 Manter Hall, Lincoln, NE 68588, USA
| | - John P DeLong
- School of Biological Sciences, University of Nebraska, 410 Manter Hall, Lincoln, NE 68588, USA
| |
Collapse
|