Biology subjects

Mastretta-Yanes, A.

Publications and source records attributed to Mastretta-Yanes, A..

4 recordsLinked to original sources

bioRxiv2026

Challenges and opportunities for integrating genetic diversity monitoring in megadiverse countries: reflections from Mexico

Megadiverse countries concentrate most of the World's biodiversity. These countries encompass different levels of research infrastructure, and nearly all of them have been historically committed to the Convention of Biological Diversity, often setting precedents and leading new approaches. Here, we ask whether the assessment of genetic diversity indicators provide novel insights for biodiversity management and conservation in one of those countries, Mexico. We evaluated the first national application of the Kunming-Montreal Global Biodiversity Framework (GBF), genetic diversity indicators in Mexico. The data covered 97 taxa across diverse ecosystem types and taxonomic groups, including crop wild relatives, to assess the capacity of genetic diversity indicators to provide novel insights, as well as their relevance for strengthening national conservation strategies. We calculated two indicators: the proportion of populations with an effective population size greater than 500 (Ne 500) and the proportion of populations maintained (PM). Data were sufficient to estimate the Ne 500 indicator for 47 taxa and the PM for 28 taxa, with mean indicator values of 0.217 and 0.936, respectively. Species' geographic range was positively associated with Ne 500, whereas national endemicity had no significant effect. Comparisons with the IUCN Red List and Mexico's national extinction-risk legislation revealed that genetic vulnerability occurs even among taxa not currently recognized as threatened. Our findings highlight a gap in legal recognition of genetic diversity protection that could be strengthened by incorporating population-level assessments focused on maintaining adaptive potential in the long-term. Additionally, the indicators allowed to highlight conservation concerns within crop wild relatives, though fully realizing their potential requires integrating the entire wild-to-domesticated complex. The Mexican experience highlights that the main challenge for scaling the monitoring of genetic diversity is not only generating new data, but integrating existing information into systems that strengthen collaboration and communication among researchers, local communities, and government institutions.

evolutionary biology↗

bioRxiv2026

Woodland age, ancient trees, and population size as proxies of genetic diversity

Climatic and biogeographic variables are often used as a proxy for tree genetic diversity, but local factors can also influence it. We propose that woodland age, presence of ancient trees, and population size could impact genetic diversity. Using the RBG Kew UK National Tree Seed Project as a study case, we examined how these factors are accounted for during seed collection. We found 42% of tree seed collections come from ancient woodlands and that 8.4% overlap with ancient trees. Sampled forest patches size ranges from few individuals to several thousand. We then carried out a pilot to examine the role of population size on functional traits variation, testing the relationship between population size and seed germination and seedling thermal stress sensitivity in three populations of the Betula pubescens Ehrh. complex. We found that seeds and seedlings from larger populations showed higher fitness and stress resistance. Our results highlight the importance of local factors to predict variation in functional traits, relevant for tree resilience. Existing seed collections of native species stored in conservation seed banks offer a valuable resource to explore these factors and improve our understanding of genetic diversity in tree populations, with implications for biodiversity conservation and forestry production.

plant biology↗

bioRxiv2025

Diversity and genetic structure within a Mexican maize race reveal consistent biocultural processes across geographic scales.

Understanding how genetic diversity is distributed within maize races is critical for conserving maize genetic diversity. While maize races are traditionally treated as homogeneous units to be targeted by conservation, each race may encompass genetically distinct populations of landraces, shaped by environmental conditions and farmer selection. In this study, the genetic diversity and population structure of the Olotillo race were examined using 89,810 SNPs from 158 samples collected across local, regional, and national scales in Mexico. Additional samples from other races Dzit-bacal, Tuxpeno, and a Mix, group combining Olotillo with other varieties, brought the total to 171 individuals. Population structure analyses (ADMIXTURE, PCA) revealed that genetic clusters do not align with race identity, but instead reflect geographic origin. Inbreeding depression was evident within Olotillo populations, with mean FIS = 0.746 {+/-} 0.066. A heterozygote deficiency was observed: mean HeOB = 0.075 {+/-} 0.020, compared to a higher expected heterozygosity (HeEX = 0.295 {+/-} 0.002). Expected homozygosity (HOEX) of 0.705{+/-} 0.002 was observed, reflecting reduced effective genetic variation. The above is reflected in the population contraction signal (e.g., positive Tajimas D), and no significant differences between scales in HeEX, HOEX, and nucleotide diversity ({pi}), suggesting that similar evolutionary forces act across regions with a strong directional selection. These findings underscore the need to ascertain the genetic background among races and to recognize meaningful within-race differentiation. Conservation actions should reflect this structure, promoting targeted seed exchange to counteract genetic erosion while respecting farmer preferences. Olotillo exemplifies how maize diversity is structured not only by genetics, but by cultural and management systems that shape evolution in situ.

genetics↗

bioRxiv2021

Incorporating evolutionary and threat processes into crop wild relatives conservation

Biodiversity conservation calls for spatial explicit approaches to maximize the representation and persistence of genetic diversity given species idiosyncratic threats in mosaic landscapes, but conservation planning methodologies seldom account for this. Here, we introduce a novel approach that uses proxies of genetic diversity to identify conservation areas, applying systematic conservation planning tools to produce hierarchical prioritizations of the landscape. It accounts for: (i) evolutionary processes, including historical and environmental drivers of genetic diversity, and (ii) threat processes, considering taxa specific tolerance to human-modified habitats and their extinction risk status. We illustrate our approach with crop wild relatives (CWR) because their intra- and interspecific diversity is important for crop breeding and food security. Although we focus on Mesoamerican CWR within Mexico, our methodology offers new opportunities to effectively guide conservation and monitoring strategies to safeguard the evolutionary resilience of any taxa, including in regions of complex evolutionary histories and mosaic landscapes.

ecology↗