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Ricardo Martinez-Garcia

Ricardo Martinez-Garcia
ICTP - South American Institute for Fundamental Research · ICTP - South American Institute for Fundamental Research

PhD

About

67
Publications
12,084
Reads
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465
Citations
Additional affiliations
September 2019 - August 2020
ICTP - South American Institute for Fundamental Research & UNESP
Position
  • Professor (Assistant)
August 2014 - September 2019
Princeton University
Position
  • PostDoc Position
October 2010 - July 2014
University of the Balearic Islands
Position
  • PhD Student
Education
October 2010 - June 2014
Institute for Cross Disciplinary Physics and Complex Systems (UIB-CSIC)
Field of study
  • Statistical Physics
October 2010 - September 2011
October 2006 - June 2010
Universidad de La Laguna
Field of study
  • Physics

Publications

Publications (67)
Article
Full-text available
We investigate the relationship between communication and search efficiency in a biological context by proposing a model of Brownian searchers with long-range pairwise interaction. After a general study of the properties of the model, we show an application to the particular case of acoustic communication among Mongolian gazelle, for which data are...
Article
Full-text available
Increased fragmentation caused by habitat loss represents a major threat to the persistence of animal populations. How fragmentation affects populations depends on the rate at which individuals move between spatially separated patches. Whereas negative effects of habitat loss on biodiversity are well-known, effects of fragmentation per se on popula...
Article
Self-organized spatial patterns are ubiquitous in ecological systems and allow popula- tions to adopt non-trivial spatial distributions starting from disordered configurations. These patterns form due to diverse nonlinear interactions among organisms and between organisms and their environment, and lead to the emergence of new (eco)system-level pro...
Preprint
Ecologists use the net biotic interactions among plants to predict fundamental ecosystem features. Following this approach, ecologists have built a giant body of theory founded on observational evidence. However, due to the limitations that a phenomenological approach raises both in empirical and theoretical studies, an increasing number of scienti...
Preprint
Full-text available
Increased fragmentation caused by habitat loss presents a major threat to the persistence of animal populations. Whereas the negative effects of habitat loss on biodiversity are well-known, the effects of fragmentation per se on population dynamics and ecosystem stability remain less understood. How fragmentation affects populations is strongly det...
Preprint
Full-text available
Regular vegetation patterns have been predicted to indicate a system slowing down and possibly desertification of drylands. However, these predictions have not yet been observed in dryland vegetation due to the inherent logistic difficulty to gather longer-term in situ data. Here, we use recently developed methods using remote-sensing EVI time-seri...
Article
Full-text available
We introduce and analyze a spatial Lotka-Volterra competition model with local and nonlocal interactions. We study two alternative classes of nonlocal competition that differ in how each species’ characteristics determine the range of the nonlocal interactions. In both cases, nonlocal interactions can create spatial patterns of population densities...
Preprint
Full-text available
Self-organized spatial patterns of vegetation are frequent in water-limited regions and have been suggested as important indicators of ecosystem health. However, the mechanisms underlying their emergence remain unclear. Some theories hypothesize that patterns could result from a water-mediated scale-dependent feedback (SDF), whereby interactions fa...
Article
Full-text available
We introduce an asymmetric noisy voter model to study the joint effect of immigration and a competition-dispersal tradeoff in the dynamics of two species competing for space in regular lattices. Individuals of one species can invade a nearest-neighbor site in the lattice, while individuals of the other species are able to invade sites at any distan...
Article
The exploitative segregation of plant roots (ESPR) is a theory that uses a game-theoretical model to predict plant root foraging behavior in space. The original model returns the optimal root distribution assuming exploitative competition between a pair of identical plants in soils with homogeneous resource dynamics. In this short communication, we...
Article
Full-text available
Ecologists have long been interested in linking individual behavior with higher‐level processes. For motile species, this ‘upscaling’ is governed by how well any given movement strategy maximizes encounters with positive factors, and minimizes encounters with negative factors. Despite the importance of encounter events for a broad range of ecologic...
Preprint
Ecologists use the net biotic interactions among plants as a major factor to predict other ecosystem features, such as species diversity, community structure, or plant atmospheric carbon uptake. By adopting this approach, ecologists have built a giant body of theory founded on observational evidence. However, growing evidence points out that this m...
Preprint
Full-text available
We introduce and analyze a spatial Lotka-Volterra competition model with local and nonlocal interactions. We study two alternative classes of nonlocal competition that differ in how each species' characteristics determine the range of the nonlocal interactions. In both cases, nonlocal interactions can create spatial patterns of population densities...
Article
Plant roots determine carbon uptake, survivorship, and agricultural yield and represent a large proportion of the world’s vegetation carbon pool. Study of belowground competition, unlike aboveground shoot competition, is hampered by our inability to observe roots. We developed a consumer-resource model based in game theory that predicts the root de...
Preprint
Full-text available
We introduce an asymmetric noisy voter model to study the joint effect of immigration and a competition-dispersal tradeoff? in the dynamics of two species competing for space on a one-dimensional lattice. Individuals of one species can invade a nearest-neighbor site in the lattice, while individuals of the other species are able to invade sites at...
Preprint
Full-text available
Community ecologists value the phenomenological observation of plant biotic interactions because they provide assumptions to make predictions of other ecosystem features, such as species diversity, community structure, or plant atmospheric carbon 20 uptake. However, a rising number of scientists claim for the need of a mechanistic understanding of...
Preprint
Full-text available
1. Ecologists have long been interested in linking individual behavior with higher-level processes. For motile species, this 'upscaling' is governed by how well any given movement strategy maximizes encounters with positive factors, and minimizes encounters with negative factors. Despite the importance of encounter events for a broad range of ecolo...
Article
Full-text available
Encounter rates link movement strategies to intra- and inter-specific interactions, and therefore translate individual movement behavior into higher-level ecological processes. Indeed, a large body of interacting population theory rests on the law of mass action, which can be derived from assumptions of Brownian motion in an enclosed container with...
Article
Full-text available
Loners—individuals out of sync with a coordinated majority—occur frequently in nature. Are loners incidental byproducts of large-scale coordination attempts, or are they part of a mosaic of life-history strategies? Here, we provide empirical evidence of naturally occurring heritable variation in loner behavior in the model social amoeba Dictyosteli...
Article
Full-text available
Eco-evolutionary frameworks can explain certain features of communities in which ecological and evolutionary processes occur over comparable timescales. Here, we investigate whether an evolutionary dynamics may interact with the spatial structure of a prey-predator community in which both species show limited mobility and predator perceptual ranges...
Preprint
Full-text available
Encounter rates link movement strategies to intra- and inter-specific interactions, and therefore translate individual movement behavior into higher-level ecological processes. Indeed, a large body of interacting population theory rests on the law of mass action, which can be derived from assumptions of Brownian motion in an enclosed container with...
Preprint
Full-text available
Encounter rates link movement strategies to intra- and inter-specific interactions, and therefore translate individual movement behavior into higher-level ecological processes. Indeed, a large body of interacting population theory rests on the law of mass action, which can be derived from assumptions of Brownian motion in an enclosed container with...
Preprint
Full-text available
Eco-evolutionary frameworks can explain certain features of communities in which ecological and evolutionary processes occur over comparable timescales. In the particular case of prey-predator systems, a combination of empirical and theoretical studies have explored this possibility, showing that the evolution of prey traits, predator traits or the...
Chapter
Full-text available
Microbial modelling is today a central aspect of ecological theory applied to microorganisms. Ecological theory and numerical modelling are essential for developing a deeper understanding of the mechanisms that shape the assembly and evolution of microbial communities. Microbes have complex interactions among them and with their local environment,...
Preprint
Full-text available
Loners, individuals out-of-sync with a coordinated majority, occur frequently in nature. Are loners incidental byproducts of large-scale synchronization attempts or are they part of a mosaic of life-history strategies? Here, we provide the first empirical evidence of naturally occurring heritable variation in loner behavior, using the social amoeba...
Data
List of parameters used in the model, including whether it represents an environmental factor (EF), a bacterial trait (BT) or an interaction between them. (DOCX)
Data
Schematic of the experimental setup and the model updating rules. a) Experimental chamber, its tiles or viewing fields, and model representation of one of the tiles as a 2D lattice with one cell at each lattice box. b) Cell displacement due to shoving following cell division occurs with probability ps. With complementary probability 1-ps the reside...
Data
Correlation length versus initial density. Mean correlation length, ξ, for different colonization strategies (σ, ρ0) in several ecological conditions given by the flow intensity f. Each curve represents a cell adhesiveness σ. The color code is maintained in all the panels. Averages are taken over 2x106 independent model realizations. (TIF)
Data
Size effect analysis. Sensitivity analysis of the effect of system size in the simulations output. (DOCX)
Data
Correlation length versus cell adhesiveness. Mean correlation length, ξ, for different colonization strategies (σ, ρ0) in several ecological conditions given by the flow intensity f. Each curve represents a value of the initial density, ρ0. The color code is maintained in all the panels. Averages are taken over 2x106 independent model realization....
Data
Skewness of the correlation length. Skewness of the distribution of correlation lengths for different colonization strategies (σ, ρ0) and ecological conditions, given by the flow intensity f. Each curve represents a value of the adhesiveness σ, whose color code is maintained in all the panels. The skewness is obtained from 2x106 independent realiza...
Data
Median correlation length. Median of the correlation length distribution for different colonization strategies (σ, ρ0) and ecological conditions given by the flow intensity f. Each curve represents a value of the adhesiveness σ. The color code is maintained in all the panels. The median is obtained from a set of 2x106 independent model realizations...
Data
Cluster size variability. a) f = 0.25, b) f = 0.375, c) f = 0.5, d) f = 1. Each curve represents the standard deviation in ξ for a given adhesiveness, σ. Color code is maintained in all the panels. Averages are taken over 2x106 independent model realizations. (TIF)
Data
Correlation function of individual model realizations. Correlation functions obtained for single realizations of the model at low (panel a; ρ0 = 10−3 cells/μm2) and high (panel b; ρ0 = 10−1 cells/μm2) initial density of cells. Correlation functions are obtained for the patterns shown in the snapshots. The color code indicates whether the pattern co...
Article
Full-text available
Biofilms are microbial collectives that occupy a diverse array of surfaces. The function and evolution of biofilms are strongly influenced by the spatial arrangement of different strains and species within them, but how spatiotemporal distributions of different genotypes in biofilm populations originate is still underexplored. Here, we study the or...
Preprint
Biofilms are microbial collectives that occupy a diverse array of surfaces. The function and evolution of biofilms are strongly influenced by the spatial arrangement of different strains and species within them, but how spatiotemporal distributions of different genotypes in biofilm populations originate is still underexplored. Here, we study the or...
Article
Full-text available
Vegetation patterns are abundant in arid and semiarid ecosystems, but how they form remains unclear. One of the most extended theories lies in the existence of scale-dependent feedbacks (SDF) in plant-to-plant and plant-water interactions. Short distances are dominated by facilitative interactions, whereas competitive interactions dominate at large...
Article
Full-text available
This thesis focuses on the applications of mathematical tools and concepts brought from nonequilibrium statistical physics to the modeling of ecological problems. The first part provides a short introduction where the theoretical concepts and mathematical tools that are going to be used in subsequent chapters are presented. Firstly, the different l...
Article
Full-text available
Many natural processes rely on optimizing the success ratio of a search process. We use an experimental setup consisting of a simple online game in which players have to find a target hidden on a board, to investigate how the rounds are influenced by the detection of cues. We focus on the search duration and the statistics of the trajectories tr...
Article
Full-text available
Studies of social microbes often focus on one fitness component (reproductive success within the social complex), with little information about or attention to other stages of the life cycle or the ecological context. This can lead to paradoxical results. The life cycle of the social amoeba Dictyostelium discoideum includes a multicellular stage in...
Data
Continuous mechanism. Detailed description and analysis of the continuous aggregation mechanism. (PDF)
Data
Sensitivity analysis for the initial condition and the Michaelis-Menten rates. A) The initial population size does not modify the winning genotype, only the transient dynamics. Highly diluted initial populations initially favor genotypes with a high division rate. However, once the total population reaches the carrying capacity, genotypes with a fa...
Data
Sensitivity analysis for different choices of survival cost function β in deterministic environments. Modifying the tradeoff between cell survival and cell size leads to selection for different division rates in the α = 0 environments. A, B, C) The top row shows three families of curves where the survival advantage of bigger cells against the small...
Data
Temporal evolution of populations in stochastic environments. A) Winning genotype in each environment, given by its investment in spores, α (blue squares), and division rate, c (red circles). Three environments are chosen and marked with a green circle. B,C) For intermediate environments (λT = 100 hour and λT = 358 hour respectively), populations s...
Data
Sensitivity analysis of the winning genotype for the choice of survival cost function, β. Increasing the survival probability of bigger cells over time (β = 5.1 − 8c) reduces selection for fast reproducing strains. The cost of small spores in terms of germination survival was not changed, so fast spore-selecting environments select for the same div...
Data
Tradeoff between number of spores and cell and spore size under different simulation settings. When the strains are plated on abundant resources and grow exponentially during a fixed time, followed by sudden starvation, A) the population size and B) the number of spores correlate positively with the division rate. Logarithmic scale used for the ver...
Data
Description of the model parameters and their values. The lower part of the table gives the parameters that are allowed to evolve. (DOCX)
Data
Short-time evolution of populations in deterministic environments. A) Winning genotype in each environment, given by its investment in spores α (blue squares), and division rate c (red circles). Three environments are chosen and marked with a green circle, two of them select for α = 0 strategies and one for α = 1. B) Fast-recovery environment (T =...
Article
Full-text available
Studies of cooperation in microbes often focus on one fitness component, with little information about or attention to the ecological context, and this can lead to paradoxical results. The life cycle of the social amoeba Dictyostelium discoideum includes a multicellular stage in which not necessarily clonal amoebae aggregate upon starvation to form...
Article
Full-text available
D. discoideum has been recently suggested as an example of bet-hedging. Upon starvation a population of unicellular amoebae splits between aggregators, which form a fruiting body made of a stalk and resistant spores, and non-aggregators. Spores are favored by long starvation periods, but vegetative cells can exploit resources in fast-recovering env...
Article
Full-text available
We study the spatial patterns formed by a system of interacting particles where the mobility of any individual is determined by the population crowding at two different spatial scales. In this way we model the behavior of some biological organisms (like mussels) that tend to cluster at short ranges as a defensive strategy, and strongly disperse if...
Article
Full-text available
Cellular slime molds, including the well-studied Dictyostelium discoideum, are amoebae whose life cycle includes both a single-cellular and a multicellular stage. To achieve the multicellular stage, individual amoebae aggregate upon starvation to form a fruiting body made of dead stalk cells and reproductive spores, a process that has been describe...
Article
Full-text available
We introduce a model of interacting random walkers on a finite one dimensional chain with absorbing boundaries or targets at the ends. Walkers are of two types: informed particles that move ballistically towards a given target, and diffusing uninformed particles that are biased towards close informed particles. This model mimics the dynamics of hie...
Article
Full-text available
The minimal ecological requirements for formation of regular vegetation patterns in semiarid systems have been recently questioned. Against the general belief that a combination of facilitative and competitive interactions is necessary, recent theoretical studies suggest that, under broad conditions, nonlocal competition among plants alone may indu...
Article
Full-text available
We investigated the relationships between search efficiency, movement strategy, and non-local communication in the biological context of animal foraging. We considered situations where the members of a population of foragers perform either Gaussian jumps or Levy flights, and show that the search time is minimized when communication among individual...
Article
Full-text available
Regular vegetation patterns in semiarid ecosystems are believed to arise from the interplay between long-range competition and facilitation processes acting at smaller distances. We show that, under rather general conditions, long-range competition alone may be enough to shape these patterns. To this end we propose a simple, general model for the d...
Article
Full-text available
We propose a model equation for the dynamics of tree density in mesic savannas which considers long-range competition among trees and the effect of fire indirectly acting as a local facilitation mechanism. Despite the fact that we take short-range facilitation to the local-range limit, the standard full spectrum of spatial structures already obtain...
Article
Full-text available
The effect of temporal disorder on systems with up-down Z2 symmetry is studied. In particular, we analyze two well-known families of phase transitions: the Ising and the generalized voter universality classes, and scrutinize the consequences of placing them under fluctuating global conditions. We observe that variability of the control parameter in...
Article
Full-text available
The decoherence effect of spatial atomic dispersion on entangled states prepared between two non-interacting atoms that pass through a resonant electromagnetic cavity is studied in detail. Entanglement is shown to oscillate with the atom–field interaction time with an amplitude that decays due to inho-mogeneous coupling strength. An upper bound for...