Geographic and taxonomic biases in the vertebrate tree of life

Abstract

Aim Resolving the tree of life is among the greatest challenges for modern biology, yet genetic data for many species are lacking to infer their position in the tree with confidence. In fact, little is known about what the missing species are and where to look for them. I identify main hotspots that host the most unsampled vertebrate species and test the hypothesis that local diversity determines the degree of sampling effort. Location Global. Taxon Terrestrial vertebrates (amphibians, birds, mammals, reptiles). Methods I use published distributional data and search DNA sequence repositories to identify taxa with no genetic data available. I map spatial patterns of the unsampled diversity and sampling effort to test the effect of species richness on sampling completeness. I examine the dependence of country‐level sampling completeness on the country's socio‐economic development. Results About 24% of living terrestrial vertebrate species have no genetic data available. The Andes, Central Africa and the Malay Archipelago are the most unsampled. Sampling effort is highest in North America, continental South‐East Asia and Amazonia. In contrast, Central Africa, the Horn of Africa, Malay Archipelago and Andes are consistently the least sampled regions. Regions of low diversity are better sampled than biodiversity hotspots. Main conclusions The most unsampled species are in the tropics. I pinpoint several key regions that are least represented in the tree of life and where sampling should be prioritized. Country's wealth seems to be an informative proxy for its sampling completeness.

Assessing digital accessible botanical knowledge and priorities for exploration and discovery of plant diversity across Mesoamerica

“…The extent of the shortfalls we uncovered for Mesoamerican vascular plants is shared by other regions and taxonomic groups (Sousa‐Baena et al ., 2014; Tessarolo et al ., 2017; Daru et al ., 2018; Girardello et al ., 2019; Stropp et al ., 2020; Rocha‐Ortega et al ., 2021; Sobral‐Souza et al ., 2021; Šmíd, 2022). At the coarser spatial resolution (60 arc‐min), we estimated a median completeness of 73.9% across Mesoamerica, but < 5% of grid cells can be considered to be well sampled (completeness > 90%); data coverage decreases at finer spatial resolutions.…”

“…The phylogenetic shortfall in vascular plants translates into less than half (44%) of the original GBIF occurrence records being adequate to implement spatial phylogenetic analyses. As observed in other groups of organisms, the phylogenetic shortfall is not randomly distributed across space (Šmíd, 2022); the phylogenetic shortfall can result in biased estimates of phylogenetic diversity and have nonnegligible impacts on spatial analyses and management strategies aimed at identifying regions with maximal phylogenetic diversity (Park et al ., 2018).…”

Drivers of species knowledge across the Tree of Life

“…Widespread evidence indicates that biodiversity research has concentrated on certain lineages, habitats and geographic regions over others [8][9][10][11][12]. At the species level, for example, research interests and conservation efforts are often skewed toward vertebrates rather than other animals [13][14][15], plants [16,17], or fungi [18,19].…”

“…Widespread evidence indicates that biodiversity research has concentrated on certain lineages, habitats and geographic regions over others (Clark and May, 2002; García-Roselló et al, 2023; Hortal et al, 2015; Mammola et al, 2023; Šmíd, 2022; Troudet et al, 2017). At the species level, for example, research interests and conservation efforts are often skewed toward vertebrates rather than other animals (Cardoso et al, 2011b, 2011a; Leather, 2013), plants (Adamo et al, 2022; Balding and Williams, 2016) or fungi (Gonçalves et al, 2021; Oyanedel et al, 2022).…”

“…Importantly, most attempts to quantify which features make species attractive to humans have focused on vertebrates—typically mammals and birds (Haukka et al, 2023; Miralles et al, 2019). This means we now possess a growing understanding of research biases for selected taxa (Guedes et al, 2023; Šmíd, 2022; Sumner et al, 2018; Zvaríková et al, 2021), but we still lack a comprehensive picture of cross-taxa features that could drive human interest in biodiversity. Here, we explored research and societal interest in organisms across the Tree of Life, asking two general questions: What are the species-level and cultural drivers of scientific interest throughout the Tree of Life?…”