The Dávalos Lab conducts research on extinction and survival in deep time, genetics and genomics of non-model vertebrates, and deforestation.
William Thomas won the Society for Systematic Biologists' Graduate Student Research Award! The award will help William generate population genetic/epigenetic data for discovering shrew wintering adaptations!
Kristjan Mets won the Presidential Dissertation Completion Fellowship! The award will help Kristjan to complete his dissertation over the summer!
Liliana M. Dávalos is Professor of Conservation Biology at Stony Brook University’s Department of Ecology and Evolution. Her research interests include molecular evolution, phylogenetics, and tropical conservation.
PhD in Ecology, Evolution,and Environmental Biology, 2004
Columbia University (New York, New York)
Certificate in Environmental Policy Studies, 2001
Columbia University (New York, New York)
BSc in Biology (emphasis on Genetics), 1997
Universidad del Valle (Cali, Colombia)
Taught evolution and researched molecular ecology
This annual lecture, like the Environmental Studies Program, takes an interdisciplinary approach to the natural environment and human interaction with it.Watch video
To investigate evolution and mechanisms of seasonal reversible size changes in a mammal.See notice
For outstanding teaching and true caring for students.
Symposia bring together outstanding young scientists to discuss exciting advances and opportunities in a broad range of disciplines.See profile
Data available to new students. Why are bats so likely to carry coronaviruses, yet seem little affected by them? Many studies have focused on their immune system, but there is much to learn about the cells viruses attack upon entry.
Data available to new students. All aspects of society have been upended by COVID-19. While most research has understandably focused on clinical applications, how the ancestors of SARS-CoV2 survive and circulate in nature is vital to both prevent future epidemics and help health professionals develop therapeutic treatments.
In support of RA Kristjan Mets. While scientific reaction to the COVID-19 pandemic has been swift, the risk of SARS-CoV-2 spilling back into native North American wildlife and feral domestic animals remains underexplored. Experimental infections of a variety of hosts, serological analyses of the cats in Wuhan, and cases of COVID-19 among tigers and lions in the Bronx Zoo, all have shown transmission back to wildlife and feral cats is highly probable. Tools are urgently needed to determine which of these animal populations are at greatest risk of establishing a native reservoir, and where the overlap with human populations is greatest. We propose to model the risk of spillover to animal populations and conversely the risk of future secondary spillover by combining models of molecular interaction between the virus and potential hosts, with multi- species Susceptible-Infectious-Recovered (SIR) models. Complementing decades of experience in vertebrate genomics (Dávalos) with expertise in epidemiology (Meliker), and spatial dynamics of wildlife disease (Mets), ours is the ideal team to quickly generate and test the necessary models to avert this risk.
To answer the question of how the shrew shrinks and then regrows its brain, we will establish this unusual species as a new model, by studying the biological, molecular, biochemical and genetic processes behind this reversible size change.
Data available for new students. We assembled a group of socio-environmental scientists to analyze and model the natural and human factors that determine the extinction and resilience of insular vertebrate fauna and leverage this understanding into metrics for use in conservation assessments.
We propose to develop a cross-scale research program that focuses on the relationships between phylogenetic diversity, genetic diversity and functional diversity of a biologically and economically important taxonomic group; bats.
Data available to new students. This project focuses on pairs of closely related bat species that sharply differ in their longevity. Detailed genome comparisons between closely related species with different life spans will test different theories of aging.
This training program responds to the challenges of new careers at the interface between science and decision making with an interdisciplinary set of new courses and a suite of activities united by the theme of “Scientific Training and Research to Inform DEcisions” (STRIDE).
Data available to new students. The project focuses on a relatively unexplored yet crucial aspect of plant-animal mutualisms; volatile chemical communication between plants and vertebrate frugivores.
Data available to new students. This project focuses on a diverse group of tropical bats in which various species evolved acute, specialized hearing, supersensitive eyes, the ability to smell subtle plant chemicals, or highly developed vomeronasal systems (thought to contribute to mating and social hierarchy).
The goal of this project was to discover the mechanisms underlying the survival of remnant populations in the WNS-affected area.
Noctilionoid bats comprise more than 200 species that span the entire ecological diversity of land mammals. They range from tiny insectivores and nectarivores to large carnivores, and even vampire bats. This is an unparalleled system for understanding how, when, and where bats evolved new diets, changed roosting habits and developed different kinds of echolocation. Together with the N. B. Simmons Lab, we are generating species-level phylogenies using molecular and morphological data, and including fossils of >20 extinct species. These phylogenies provide frameworks for investigating patterns and processes of ecological adaptation, speciation, and extinction across a hyperdiverse group of mammals.
The project will generate hypotheses about the evolutionary relationships of 5 different groups of bats, each containing at least one exclusively Antillean species. These evolutionary relationships will then be used to establish the timing and pattern of separation among bat species in the Antilles and their South and Central American relatives, and will also be compared with similar hypotheses about other terrestrial organisms. Drs. Nancy Simmons, Rob DeSalle, and Liliana Davalos will use standard methods for obtaining and analyzing morphological and molecular data from the study groups. Patterns of evolutionary relationships resulting from these data will be compared applying at least 5 different approaches.
Population growth with weak economic development can promote tropical deforestation, but government infrastructure investment can also open new frontiers and thus increase deforestation. In the Andean region of South America, population growth has been a leading explanation for both deforestation and coca cultivation, but coca generates armed conflict and attracts counter-drug measures, obscuring the differences between population-driven and frontier-opening models of deforestation. Using a 15-year panel from Colombia, we model deforestation, coca cultivation, and conflict victims as interrelated responses with a suite of covariates encompassing land cover, land cover changes, population, population changes, counter-drug measures, and government infrastructure spending. Infrastructure spending suppresses coca, coca and eradication by aerial fumigation both increase conflict, and conflict promotes deforestation and is associated with depopulation. But the strongest predictor of deforestation is pasture growth, which covaries with coca. While these models show that infrastructure spending can help reduce coca, and coca’s influence on deforestation is indirect and mediated by conflict, the models also reveal the most important challenge to forest conservation is neither coca nor conflict, but an insatiable appetite for land that expresses itself through pasture growth.
While evolvability of genes and traits may promote specialization during species diversification, how ecology subsequently restricts such variation remains unclear. Chemosensation requires animals to decipher a complex chemical background to locate fitness-related resources, and thus the underlying genomic architecture and morphology must cope with constant exposure to a changing odorant landscape; detecting adaptation amidst extensive chemosensory diversity is an open challenge. Phyllostomid bats, an ecologically diverse clade that evolved plant-visiting from an insectivorous ancestor, suggests the evolution of novel food detection mechanisms is a key innovation: phyllostomids behaviorally rely strongly on olfaction, while echolocation is supplemental. If this is true, exceptional variation of underlying olfactory genes and phenotypes may have preceded dietary diversification. We compared olfactory receptor (OR) genes sequenced from olfactory epithelium transcriptomes and olfactory epithelium surface area of bats with differing diets. Surprisingly, although OR evolution rates were quite variable and generally high, they are largely independent of feeding ecology. olfactory epithelial surface area, however, is greater in plant-visiting bats and there is an inverse relationship between OR evolution rates and surface area. Larger surface areas suggest greater reliance on olfactory detection and stronger ecological constraint on maintaining an already diverse OR repertoire. Instead of the typical case in which specialization and elaboration is coupled with rapid diversification of associated genes, here the relevant genes are already evolving so quickly that increased reliance on smell has led to stabilizing selection, presumably to maintain the ability to consistently discriminate among specific odorants - an ecological constraint on sensory evolution.
In most vertebrates, the demand for glucose as the primary substrate for cellular respiration is met by the breakdown of complex carbohydrates, or energy is obtained by protein and lipid catabolism. In contrast, a few bat and bird species have convergently evolved to subsist on nectar, a sugar-rich mixture of glucose, fructose, and sucrose. How these nectar-feeders have adapted to cope with life-long high sugar intake while avoiding the onset of metabolic syndrome and diabetes is not understood. We analyzed gene sequences obtained from 127 taxa, including 22 nectar-feeding bat and bird genera that collectively encompass four independent origins of nectarivory. We show these divergent taxa have undergone pervasive molecular adaptation in sugar catabolism pathways, including parallel selection in key glycolytic and fructolytic enzymes. We also uncover convergent amino acid substitutions in the otherwise evolutionarily conserved aldolase B (ALDOB), which catalyzes rate-limiting steps in fructolysis and glycolysis, and the mitochondrial gatekeeper pyruvate dehydrogenase (PDH), which links glycolysis and the tricarboxylic acid cycle. Metabolomic profile and enzyme functional assays are consistent with increased respiratory flux in nectar-feeding bats and help explain how these taxa can both sustain hovering flight and efficiently clear simple sugars. Taken together, our results indicate that nectar-feeding bats and birds have undergone metabolic adaptations that have enabled them to exploit a unique energy-rich dietary niche among vertebrates.