Biology subjects

Quiroga-Carmona, M.

Publications and source records attributed to Quiroga-Carmona, M..

8 recordsLinked to original sources

bioRxiv2026

CLIMATIC NICHE DIFFERENTIATION ACCOMPANIED THE RADIATION OF LEAF-EARED MICE IN THE PHYLLOTIS DARWINI SPECIES GROUP (SIGMODONTINAE, CRICETIDAE)

Aimto characterize the evolution of climatic niches during the diversification of the Phyllotis darwini species group, in order to assess the extent to which divergences involved in radiation were associated with patterns of conservatism or divergence of climatic niches, and whether the differentiation found among climatic niches correlated with species phylogenetic relationships. Locationsouth-central Andes, surrounding lowlands, and Patagonia, South America. Methodsspecies climatic niches were characterized by sampling contemporaneous precipitation and temperature conditions across occurrence locations and entire distributional ranges. Climatic niches were analyzed and modeled using multivariate statistics (PCA, PERMANOVA), a maximum entropy-based algorithm, and novel methods developed to explore levels of differentiation (niche overlap test) and divergence (niche divergence test) between realized and fundamental niches. Comparative phylogenetic methods were applied using a time-calibrated phylogeny and integrating climate niche data to estimate ancestral environmental niches within geographic and environmental spaces. Resultscomparisons revealed low levels of climatic niche overlap, both among species realized niches and among their fundamental niches, suggesting high levels of niche differentiation during the diversification of Phyllotis species. Quantifications of niche overlap further showed that observed differences among species lay primarily in the multidimensional nature of climatic niches, as unidimensional quantifications exhibited higher levels of overlap. Evolved differences among species climatic niches were better fitted to a Brownian motion model of evolution, but lacked phylogenetic signal and showed no significant association with species phylogenetic distances. Main conclusionslow levels of differentiation between ancestral climatic niches suggest that the early radiation of species in the Phyllotis darwini species group was promoted by geographic isolation, whereas the more recent diversification of extant species was accompanied by climatic niche differentiation, possibly involving local adaptation to regional ecoclimatic changes associated with Quaternary glacial cycles. The spatial separation of sister species, the complete divergence of their climatic niches, and the lack of phylogenetic signal in niche differences suggest a scenario of diversification in which divergences were prompted by the spatial isolation, but also by the divergent selection exerted by regional climatic differences.

evolutionary biology↗

bioRxiv2025

Elevational variation in heart mass and suppression of hypoxia-induced right ventricle hypertrophy in Andean leaf-eared mice (Phyllotis)

In lowland mammals that ascend to high elevation, hypoxia-induced changes in the pulmonary circulation can give rise to hypoxic pulmonary hypertension (HPH) and associated right-ventricle (RV) hypertrophy. Some mammals that are native to high elevation have evolved a means of attenuating HPH, demonstrating how environmental adaptation may sometimes counteract the effects of ancestral acclimatization responses. Here, we examine elevational variation in heart mass and measures of RV hypertrophy in four closely related species of leaf-eared mice (genus Phyllotis) that are broadly co-distributed across a steep elevational gradient on the Western slope of the Andes. There was a positive relationship overall between heart mass and elevation that reflected proportional changes in both the right and left ventricles. Thus, elevation-related increases in overall heart mass were not generally attributable to RV hypertrophy, suggesting that this group of predominantly highland species have evolved a means of avoiding HPH and/or attenuating the cardiac response to HPH. To gain insight into possible transcriptional mechanisms, we examined patterns of transcriptomic variation in the right ventricles of Phyllotis vaccarum from two geographically distinct highland populations (both from elevations >5000 m) that exhibit strikingly different levels of RV hypertrophy. Suppression of RV hypertrophy is associated with differential expression of key regulatory genes involved in striated muscle, immune processes, and the inflammatory response. Analysis of co-expression modules identified a promising set of candidate genes for mediating the development of RV hypertrophy at extremely high elevations.

evolutionary biology↗

bioRxiv2024

Species limits and hybridization in Andean leaf-eared mice (Phyllotis)

Leaf-eared mice (genus Phyllotis) are among the most widespread and abundant small mammals in the Andean Altiplano, but species boundaries and distributional limits are often poorly delineated due to sparse survey data from remote mountains and high-elevation deserts. Here we report a combined analysis of mitochondrial DNA variation and whole-genome sequence (WGS) variation in Phyllotis mice to delimit species boundaries, to assess the timescale of diversification of the group, and to examine evidence for interspecific hybridization. Estimates of divergence dates suggest that most diversification of Phyllotis occurred during the past 3 million years. Consistent with the Pleistocene Aridification hypothesis, our results suggest that diversification of Phyllotis largely coincided with climatically induced environmental changes in the mid- to late Pleistocene. Contrary to the Montane Uplift hypothesis, most diversification in the group occurred well after the major phase of uplift of the Central Andean Plateau. Species delimitation analyses revealed surprising patterns of cryptic diversity within several nominal forms, suggesting the presence of much undescribed alpha diversity in the genus. Results of genomic analyses revealed evidence of ongoing hybridization between the sister species Phyllotis limatus and P. vaccarum and suggest that the contemporary zone of range overlap between the two species represents an active hybrid zone.

evolutionary biology↗

bioRxiv2024

Diet of Andean leaf-eared mice (Phyllotis) living at extreme elevations on Atacama volcanoes: insights from metagenomics, DNA metabarcoding, and stable isotopes

On the flanks of >6000 m Andean volcanoes that tower over the Atacama Desert, leaf-eared mice (Phyllotis vaccarum) live at extreme elevations that surpass known vegetation limits. What the mice eat in these barren, hyperarid environments has been the subject of much speculation. According to the arthropod fallout hypothesis, sustenance is provided by windblown insects that accumulate in snowdrifts ( aolian deposits). It is also possible that mice feed on saxicolous lichen or forms of cryptic vegetation that have yet to be discovered at such high elevations. We tested hypotheses about the diet of mice living at extreme elevations on Atacama volcanoes by combining metagenomic and DNA metabarcoding analyses of gut contents with stable-isotope analyses of mouse tissues. Genomic analyses of contents of the gastrointestinal tract of a live-captured mouse from the 6739 m summit of Volcan Llullaillaco revealed evidence for an opportunistic but purely herbivorous diet, including lichens. Although we found no evidence of animal DNA in gut contents of the summit mouse, stable isotope data indicate that mice native to elevations at or near vegetation limits ([~]5100 m) include a larger fraction of animal prey in their diet than mice from lower elevations. Some plant species detected in the gut contents of the summit mouse are known to exist at lower elevations at the base of the volcano and in the surrounding Altiplano, suggesting that such plants may occur at higher elevations beneath the snowpack or in other cryptic microhabitats.

evolutionary biology↗

bioRxiv2023

Extreme high-elevation mammal surveys reveal unexpectedly high upper range limits of Andean mice

In the worlds highest mountain ranges, uncertainty about the upper elevational range limits of alpine animals represents a critical knowledge gap regarding the environmental limits of life and presents a problem for detecting range shifts in response to climate change. Here we report results of mountaineering mammal surveys in the Central Andes, which led to the discovery of multiple species of mice living at extreme elevations that far surpass previously assumed range limits for mammals. We live-trapped small mammals from ecologically diverse sites spanning >6700 m of vertical relief, from the desert coast of northern Chile to the summits of the highest volcanoes in the Andes. We used molecular sequence data and whole-genome sequence data to confirm the identities of species that represent new elevational records and to test hypotheses regarding species limits. These discoveries contribute to a new appreciation of the environmental limits of vertebrate life.

evolutionary biology↗

bioRxiv2023

Genomic and Radiocarbon Insights into the Mystery of Mouse Mummies on the Summits of >6000 m Andean Volcanoes

Our understanding of the limits of animal life is continually revised by scientific exploration of extreme environments. Here we report the discovery of numerous mummified cadavers of leaf-eared mice, Phyllotis vaccarum, from the summits of three different Andean volcanoes at elevations 6029-6233 m (19,780-20,449 ft) above sea level in the Puna de Atacama (Chile-Argentina). Such extreme elevations were previously assumed to be completely uninhabitable by mammals. In combination with a live-captured specimen of the same species from the nearby summit of Volcan Llullaillaco (6739 m [=22,110 ft]), the 13 summit mummies represent the highest physical records of mammals in the world. We report a chromosome-level genome assembly for P. vaccarum in combination with a whole-genome re-sequencing analysis and radiocarbon dating analysis that provide insights into the provenance and antiquity of the summit mice. We test alternative hypotheses to explain the existence of mouse graveyards on the summits of Atacama volcanoes. Radiocarbon data indicate that the most ancient of the mummies were at most a few centuries old. Genomic polymorphism data revealed a high degree of continuity between the summit mice and conspecifics from lower elevations in the surrounding Altiplano. Genomic data also revealed equal numbers of males and females among the summit mice and evidence of close kinship between some individuals from the same summit groups. These findings bolster evidence for self-sustaining populations of Phyllotis at elevations >6000 m and challenge assumptions about the environmental limits of vertebrate life and the physiological tolerances of small mammals.

evolutionary biology↗

bioRxiv2023

Elevational and latitudinal range extensions of the puna mouse, Punomys (Cricetidae), with the first record of the genus from Chile

We report an elevational record for the Andean sigmodontine puna mouse Punomys, which is also the first record of the genus in Chile. The record is based on a mummified specimen that we discovered at an elevation of 5,461 m (17,917) in the caldera of Volcan Acamarachi, Region de Antofagasta, Chile. Results of a morphological suggest that the specimen can be provisionally referred to the species P. lemminus. This new record also extends the known geographic distribution of the genus by 700 km to the south and brings the known Chilean mammal richness to a total of 170 living species and 88 genera. This finding highlights the need for increased survey efforts in more remote, high-elevation regions and demonstrates that there is still much to be learned about the mammal fauna of the Andean Altiplano.

zoology↗

bioRxiv2020

Discovery of the world's highest-dwelling mammal

Environmental limits of animal life are invariably revised upwards when the animals themselves are investigated in their natural habitats. Here we report results of a scientific mountaineering expedition to survey the high-altitude rodent fauna of Volcan Llullaillaco in the Puna de Atacama of northern Chile, an effort motivated by video documentation of mice (genus Phyllotis) at a record altitude of 6205 m. Among numerous trapping records at altitudes >5000 m, we captured a specimen of the yellow-rumped leaf-eared mouse (Phyllotis xanthopygus rupestris) on the very summit of Llullaillaco at 6739 m. This summit specimen represents an altitudinal world record for mammals, far surpassing all specimen-based records from the Himalayas and elsewhere in the Andes. This discovery suggests that we may have generally underestimated the altitudinal range limits and physiological tolerances of small mammals simply because the worlds highest summits remain relatively unexplored by biologists.

evolutionary biology↗