One Simple Rule Unites Life from the Deep Ocean to Vast Savannas

A groundbreaking study recently published in Nature Ecology & Evolution has unveiled a remarkably simple rule governing the organization of biodiversity across Earth’s sprawling biogeographical regions. This discovery, emerging from an international collaboration led by Umeå University, promises to shift our understanding of how species distribute themselves globally and may offer crucial insights into how ecosystems will respond to ongoing and future environmental changes.

At a glance, Earth presents a tapestry of vastly different environments, each hosting its own intricate web of species adapted to unique conditions. Mountains, oceans, and extreme climates carve the planet into isolated biogeographical regions, often acting as natural barriers to species dispersal. These divisions have resulted in distinct evolutionary histories and biodiversity patterns in each region. Despite these apparent differences, the research team has identified a surprising uniformity in the spatial patterns of species distribution, regardless of taxonomy or ecological lifestyle.

The research surveyed a broad spectrum of life forms, including amphibians, birds, mammals, reptiles, dragonflies, marine rays, and trees, encompassing organisms with drastically different movement capabilities and ecological niches. Traditionally, scientists expected that each bioregion’s species would show distinct spatial distributions influenced by their unique ecological traits and evolutionary histories. Contrary to these expectations, the study found a consistent “core-periphery” pattern echoing throughout every life form and region examined.

.adsslot_t7mBW3apj6{width:728px !important;height:90px !important;}
@media(max-width:1199px){ .adsslot_t7mBW3apj6{width:468px !important;height:60px !important;}
}
@media(max-width:767px){ .adsslot_t7mBW3apj6{width:320px !important;height:50px !important;}
}

ADVERTISEMENT

Within each bioregion, there exists a well-defined core area, a biodiversity hotspot where species richness peaks. From this core, species distributions fan outward, but their range diminishes as the distance from the core increases. Only a subset of species manages to persist in surrounding peripheral zones, indicating that these core areas provide optimal environmental conditions for survival and diversification. This repetitive pattern across multiple regions and taxa signals a fundamental organizing principle underlying Earth’s biodiversity.

The implications of these findings are profound. The existence of biodiversity cores emphasizes the disproportionate ecological importance of relatively small areas in maintaining regional species diversity. Such zones effectively serve as engines driving evolutionary diversification, colonization, and resilience against disturbances. These insights highlight new priorities for conservation that go beyond protecting individual species or habitats, pointing instead toward safeguarding these vital core regions to maintain overall bioregional biodiversity.

The team attributes the emergence of this universal pattern to environmental filtering — a core ecological mechanism where local abiotic conditions act as selective filters, allowing only species that can tolerate certain conditions (such as temperature extremes or moisture availability) to establish and thrive in an area. While environmental filtering has been a foundational theoretical concept in ecology, empirical evidence of its influence at a global scale and across different life forms has been sparse. This study provides robust quantitative support for this theory using computational simulation and modeling across diverse taxonomic groups.

Rubén Bernardo-Madrid, the lead author, explains that these cores likely represent environmental “sweet spots,” offering the combination of abiotic factors conducive to both species persistence and speciation. This mechanism essentially shapes the distribution of life by concentrating diversity in stable, resource-rich sites from which species may radiate outward but rarely establish permanent populations far from the core due to harsher, less hospitable conditions.

Beyond theoretical ecology, these insights bear significant weight for predicting how biodiversity might respond to rapid global changes, including climate change, habitat fragmentation, and human disturbances. Understanding the predictability and drivers of species distributions can enhance the development of models forecasting biodiversity loss or shifts under emerging environmental pressures. Joaquín Calatayud, a co-author, emphasizes that acknowledging the critical role of environmental filters within these core zones can improve conservation planning and management to safeguard biodiversity under future scenarios.

The methodology employed in this research involved sophisticated computational simulations and ecological modeling techniques, enabling the analysis of large, complex datasets spanning multiple continents and taxonomic groups. By integrating data on species occurrences, environmental variables, and biogeographical boundaries, the researchers were able to identify patterns invisible to traditional observational methods, reinforcing the power of computational ecology in addressing large-scale biodiversity questions.

This study also challenges previously held assumptions that species distribution patterns are primarily species-specific or contingent on unique evolutionary histories and traits. Instead, it posits a more unified framework in which environmental factors serve as a common denominator shaping bioregional biodiversity structure. This insight may prompt a reevaluation of ecological theories related to niche diversity, dispersal limitation, and speciation processes in biogeography.

From a conservation standpoint, these findings stress the urgency of protecting those small, core biodiversity areas within bioregions. Given that species richness and ecological functions concentrate in these cores, their degradation could disproportionately impair entire ecosystems’ integrity. Conservation policies and international agreements might need to recalibrate their focus, ensuring these biodiversity engines remain intact in the face of mounting anthropogenic threats.

Moreover, by revealing a universal organizing rule underpinning the distribution of life on Earth, this research bridges disciplines across biology, ecology, and computational science. It exemplifies the value of interdisciplinary collaboration, combining field data, theoretical ecology, and advanced modeling to solve complex ecological puzzles crucial for both science and society.

In summary, the discovery of a universal core-periphery pattern of species distribution across Earth’s biogeographical realms marks a milestone in ecological science. This rule not only enhances our understanding of life’s spatial organization at a planetary scale but also provides an essential tool for managing and conserving biodiversity amidst accelerating global changes.

Subject of Research: Not applicable
Article Title: A general rule on the organization of biodiversity on Earth’s biogeographical regions
News Publication Date: 4-Jun-2025
Web References: https://doi.org/10.1038/s41559-025-02724-5
Image Credits: Gabrielle Beans
Keywords: Complex systems, Biophysics, Wildlife management, Ecological modeling, Ecosystem management, Network science, Mathematical modeling, Computational biology

Tags: biodiversity patternsbiogeographical regionsecological adaptationsecological niches and movement capabilitiesenvironmental change responseevolutionary history of speciesglobal biodiversity insightsinternational ecological collaborationmarine and terrestrial ecosystemsNature Ecology & Evolution studyspecies dispersal barriersspecies distribution uniformity