Biology subjects

Okie, J. G.

Publications and source records attributed to Okie, J. G..

5 recordsLinked to original sources

bioRxiv2026

From cooperation to predation: the evolutionary origins of phagocytosis

A major transition in the evolution of eukaryotic cells was phagocytosis: the ability of one cell to engulf another. In some cases, the engulfed cell persists, forming an endosymbiosis which is often mutually beneficial. However, it is unclear whether the interaction between the ancestors was also cooperative. There are clear benefits to developing the ability to eat a competitor, but can it ever be beneficial to eat a cooperator? We use a dynamical systems framework to identify the ecological conditions under which phagocytosis can evolve from a system of cooperating microbes.Beginning with a system of two cooperating species, we use invasion analysis to identify the parameter regimes under which a phagocytosing mutant can invade and the subsequent population dynamics. We identify a critical threshold that determines whether an invading predator will coexist with the cooperative community or replace members. Repeatedly invading with different predators, we find that the system saturates when there are three coexisting species, though this community does not have a single optimal composition. However, if we incorporate additional costs, we find there is a single evolutionarily stable community of two cooperators and a pure predator. Ultimately, we show that it is possible for phagocytosis to evolve from a cooperative community and, moreover, coexist with the original cooperating species.

evolutionary biology↗

bioRxiv2026

Defusing the consumption bomb

For decades, the "population bomb" has dominated environmental discourse, arguing that high fertility rates -especially in the low income countries- drive global environmental problems. However, current trajectories show global declines in population growth rates, especially in higher development index (HDI) nations, which have the highest consumption. Here we showcase evidence for a paradigm shift from the "population bomb" to a "consumption bomb" narrative of the Anthropocene emphasizing the central role of increases in per capita energy use and CO2 production, modulated by current standard metrics for development and affluence, in transforming the Earth system. Defusing and manoaging the consumption bomb requires rethinking economic growth and wellbeing metrics, reallocating resources toward global change retribution and mitigation, especially in low HDI countries, and transitioning from continually-increasing energy expenditures, especially from fossil fuels, toward more equitable and ecologically resilient ways of living. A new sustainability science must move beyond population counts to confront the biophysical and energetic consequences of the changing cultural, economic, and technological systems that sustain ever-growing demands on Earths life-support systems.

ecology↗

bioRxiv2024

Scaling diversity, abundance and energy: the Equilibrium Theory of Biodiversity Dynamics

This preprint of a book chapter presents the newly proposed Equilibrium Theory of Biodiversity Dynamics (ETBD), whose aim is to conceptualize large-scale dynamics of species richness via addressing the population size-dependence of speciation and extinction rates, the resulting diversity-dependence of these rates, and their modulation by the environment. It provides the most general framework for understanding large-scale biodiversity patterns such as the latitudinal diversity gradient (LDG) and temporal patterns of biodiversity changes. The theory has been published elsewhere in its full form that includes all the derivations (Okie & Storch 2004, American Naturalist https://doi.org/10.1086/733103), but here it is presented in a simpler and user-friendly way, focusing on its major implications comprising macroecological scaling relationships between energy (or resource) availability, species richness and community abundance.

ecology↗

bioRxiv2023

The equilibrium theory of biodiversity dynamics: a general framework for scaling species richness and community abundance along environmental gradients

Large-scale temporal and spatial biodiversity patterns have traditionally been explained by multitudinous particular factors and a few theories. However, these theories lack sufficient generality and do not address fundamental interrelationships and coupled dynamics between resource availability, community abundance, and species richness. We propose the Equilibrium Theory of Biodiversity Dynamics (ETBD) to address these linkages. According to the theory, equilibrium levels of species richness and community abundance emerge at large spatial scales due to the population size-dependence of speciation and/or extinction rates, modulated by resource availability and the species abundance distribution. In contrast to other theories, ETBD includes the effect of biodiversity on community abundance and thus addresses phenomena such as niche complementarity, facilitation, and ecosystem engineering. It reveals how alternative stable states in both diversity and community abundance emerge from these nonlinear biodiversity effects. The theory predicts how the strength of these effects alters scaling relationships between species richness, (meta)community abundance, and resource availability along different environmental gradients. Using data on global-scale variation in tree species richness, we show how the general framework is useful for clarifying the role of speciation, extinction and resource availability in driving macroecological patterns in biodiversity and community abundance, such as the latitudinal diversity gradient.

ecology↗

bioRxiv2019

Genomic adaptations in information processing underpin trophic strategy in a whole-ecosystem nutrient enrichment experiment

Several universal genomic traits affect the capacity, cost, and efficiency of biochemical information processing underpinning metabolism and reproduction. We analyzed their role in mediating planktonic microbial community responses to nutrient enrichment in an oligotrophic, phosphorus-deficient pond in Cuatro Cienegas, Mexico--one of the first whole-ecosystem experiments involving replicated metagenomic assessments. As predicted assuming oligotrophy favors lower information-processing costs whereas copiotrophy favors higher processing rates, mean bacteria genome size was higher in the fertilized treatment, as were GC content, total number of tRNA genes, total number of rRNA genes and codon usage bias in ribosomal protein sequences. However, contrasting changes in trait variances also suggested differences between traits in mediating assembly under oligotrophic versus copiotrophic conditions. Tradeoffs in information-processing traits are apparently sufficiently pronounced to play a role in community assembly and all different components of metabolism-- information, energy, and nutrient requirements--are fine-tuned to an organisms growth and trophic strategy.

ecology↗