Biology subjects

Rodriguez-Caro, R. C.

Publications and source records attributed to Rodriguez-Caro, R. C..

4 recordsLinked to original sources

bioRxiv2024

Diseases and invasive species have synergistic effects with other anthropogenic threats on the functional and phylogenetic diversity in Testudines and Crocodilia

Understanding how multiple threats interact is crucial for the prioritization of conservation measures. Here, we investigate how interactions between six common threats (climate change, habitat disturbance, global trade, overconsumption, pollution, and emerging diseases/invasive species) affect the functional and phylogenetic diversity of 230 species of Testudines and 21 of Crocodilia. We classify two-way threat interactions into additive, synergistic, and antagonistic according to their effects on functional and phylogenetic diversity. Most threat interactions are antagonistic, the effect of threats jointly is lower than the sum of the effects of threats separately. However, we find that the interaction between emerging diseases or invasive species with other threats has synergistic and additive effects, meaning that the combined effects are greater or equal to the effects of threats separately. Our work can help target conservation strategies and detect key places to address multiple threats when they appear together.

ecology↗

bioRxiv2024

Taking advantage of reference-guided assembly in a slowly-evolving lineage: application to Testudo graeca.

BackgroundObtaining de novo chromosome-level genome assemblies greatly enhances conservation and evolutionary biology studies. For many research teams, long-read sequencing technologies (that produce highly contiguous assemblies) remain unaffordable or unpractical. For the groups that display high synteny conservation, these limitations can be overcome by a reference-guided assembly using a close relative genome. Of chelonians, terrestrial tortoises are considered one of the most endangered taxa, which calls for more genomic resources. Here we make the most of high synteny conservation in chelonians to produce the first chromosome-level genome assembly of genus Testudo with one of the most iconic tortoise species in the Mediterranean basin: T. graeca. ResultsWe used high quality, paired-end Illumina sequences to build a reference-guided assembly with the chromosome level assembly of Gopherus evgoodei. We reconstructed a 2.29 Gb haploid genome with a scaffold N50 of 107.598 Mb and 5.37% gaps. We sequenced 25998 protein-coding genes, and a 41.2% fraction was determined as repetitive in our assembled genome. Demographic history reconstruction based on the genome revealed two events (population decline and recovery) consistent with previously suggested phylogeographic patterns for the species. This outlines the value of genomes like this for phylogeographic studies. ConclusionsOur results highlight the value of using close relatives to produce de novo draft assemblies in species where such resources are unavailable. Our Testudo graeca annotated genome paves the way to delve deeper into the species evolutionary history and provides a valuable resource to increase making direct conservation efforts on their threatened populations.

genomics↗

bioRxiv2022

The extinction of threatened species by anthropogenic threats endangers the functional diversity of turtles and crocodiles

The Anthropocene is tightly associated with a drastic loss of species worldwide and the disappearance of their key ecosystem functions. The on-going reduction in ecosystem functionality is driven by global and local threats. The orders Testudines (turtles and tortoises) and Crocodilia (crocodiles, alligators, and gharials) contain numerous threatened, long-lived species for which their functional diversity and potential erosion by anthropogenic impacts remains unknown. Here, we examine 259 (69%) of the existing 375 species of Testudines and Crocodilia, quantifying their life history strategies (i.e., schedules of survival, development, and reproduction) from open-access data on their demography, ancestry, and threats. We find that the loss of functional diversity in simulated extinction scenarios of threatened species is greater than expected by chance. Moreover, the effects of unsustainable local consumption, diseases, and pollution are associated with specific functional strategies. In contrast, climate change, habitat disturbance, and global trade affect all species independent of their life history strategy. Importantly, the loss of functional diversity for threatened species by habitat disturbance is twice that for all other threats. Our findings highlight the importance of conservation programmes focused on preserving the functional diversity of life history strategies jointly with the phylogenetic representativity of these highly threatened groups.

ecology↗

bioRxiv2020

The demographic buffering strategy has a threshold of effectiveness to increases in environmental stochasticity

O_LIAnimal populations have developed multiple strategies to deal with environmental change. Among them, the demographic buffering strategy consists on constraining the temporal variation of the vital rate(s) (e.g., survival, growth, reproduction) that most affect(s) the overall performance of the population. Given the increase in environmental stochasticity of the current global change scenario, identifying the thresholds beyond which populations are not able to remain viable -despite their potential buffering strategies- is of utmost importance. C_LIO_LITortoises are known to buffer the temporal variation in survival (i.e. this vital rate has the highest contribution to the population growth rate{lambda} ) at the expense of a high variability on reproductive rates (lowest contribution to{lambda} ). To identify the potential threshold in buffering ability, here we use field data collected across a decade on 15 locations of Testudo graeca along South-Eastern Spain. We analyse the effects of environmental variables (precipitation, temperature, and NDVI) on the probability of laying eggs and the number of eggs per clutch. Finally, we couple the demographic and environmental data to parametrise integral projection models (IPMs) to simulate the effects of different scenarios of drought recurrence on population growth rate. C_LIO_LIWe find that droughts negatively affect the probability of laying eggs, but the overall effects on the population growth rates of T. graeca under the current drought frequencies (one per decade) are negligible. However, increasing the annual frequency of droughts decreases the buffering ability of T. graeca populations, with a threshold at three droughts per decade. C_LIO_LIAlthough some species may buffer current environmental regimes by carefully orchestrating how their vital rates vary through time, a demographic buffering strategy may alone not warrant population viability in extreme regimes. Our findings support the hypothesis that the buffering strategy indeed has a threshold of effectiveness. Our methodological approach also provides a useful pipeline for ecologists and managers to determine how effective the management of environmental drivers can be for demographically buffering populations, and which scenarios may not provide long-term species persistence. C_LI

ecology↗