Seminarios de Frontera
Macroevolution to Microbiomes: Piecing Together the Puzzle to Understand the Evolution of the Ants
To fully understand the macroevolutionary factors that have promoted the diversification and persistence of biological diversity varied tools and disciplines must be integrated. By combining data from several fields including molecular phylogenetics/phylogenomics, comparative genomics, biogeographic range reconstruction, stable isotope analyses, and microbial community sequencing to study the evolutionary history of the insects, we are beginning to understand the drivers of speciation and the interconnectedness of life. Comparative phylogenetic analysis reveals the interconnectedness of ants and plants and that ants diversified after the rise of the angiosperms. Comparative genomics has permitted the exploration of the role of symbiosis on genome evolution and behavioral gene evolution demonstrating that Red Queen dynamics are at play in obligate mutualisms. While studies combining stable isotope analysis to infer the trophic ecology of the ants and next-generation sequencing of gut-associated bacteria of ants highlight the importance of this microbiome association in the evolution of herbivory. Microbial contributions to ants are not limited to diet enrichment and we find evidence for their role in cuticle formation. These multiple lines of evidence are illuminating a more complete picture of ant evolution and providing novel insights into the role that symbiosis plays to promote biological diversity.
Corrie Moreau
Cornell University
The evolution of sleep loss in Mexican cavefish
Sleep is nearly ubiquitous throughout the animal kingdom, yet its duration and timing varies dramatically between species. We have developed the Mexican tetra, Astyanax mexicanus as a model to study evolved changes in sleep, and how naturally occurring genetic variation encodes for sleep differences between individuals. These fish exist as eyed-surface populations that inhabit the rivers of northeast Mexico and multiple blind cave populations that have converged on sleep loss. We have identified neuromodulators that contribute to the evolution of sleep loss in A. mexicanus cavefish including upregulation of the wake-promoting neuropeptide Hypocretin/Orexin. In addition, we have developed transgenic and gene-editing methodology in this emergent model system allowing for systematic investigation of the genes and neurons regulating evolved differences in sleep. Systematic analysis has identified convergence on wide-spread neuroanatomical differences between surface fish and cavefish including hypothalamic expansion that is accompanied by increased sleep intensity. Current studies seek to identify how naturally occurring genetic variation contributes do these phenotypes. Investigating the mechanisms of sleep loss in Mexican cavefish has potential to provide insights into the variation in sleep need throughout the animal kingdom. Further, the resources developed to study sleep can be broadly applied to study other cavefish associated traits including obesity, diabetes, and dysregulation of stress response.
Alex Keene
Texas A&M University
Linkages among plant demography, indigenous stewardship, and conservation
Globally, an estimated 20% of plants are at risk of extinction, with habitat conversion and harvest representing the largest threats. At least 30, 000 plant species are known to be wild-harvested by people, and wild-plant harvesting is prevalent across both the global north and south, and in both rural and urban areas. A growing number of studies have documented the decline of plant populations and the factors responsible, but there remains comparatively little demographic research that identifies the drivers underlying sustainable use. I draw on case-studies of wild plants harvested by local and indigenous communities in the context of global change drivers, and use methods from plant demography, population modeling and ethnography, to illustrate the ways in which multiple drivers can interact to shape plant population persistence. Together, the results point to local and global avenues for promoting conservation and monitoring sustainable use; and highlight the reciprocal learning that emerges from collaborations with local and indigenous stewards.
Tamara Ticktin
University of Hawai'i at Mānoa
Using the Canidae fossil record to study how species interactions might affect origination and persistence in deep time
In this seminar, I will discuss how we typically study the effect of species interaction on diversification dynamics. I will pay special attention to macroevolutionary studies that use data from the fossil record and those particularly interested in the effect of interspecific competition. I will present some recent and unpublished results from my research group that have used data on Carnivora, specifically the family Canidae, to suggest more direct ways to study the effect of interspecific competition and its macroevolutionary effects.
Tiago Quental
Universidade de São Paulo (USP) Brasil
Neotropical plant fossils: Insights into the early evolution of modern tropical rainforests
Plant fossils from tropical America have provided new evidence on the history of tropical vegetation in deep time. From mixed rainforest assemblages of the Cretaceous to modern-like Paleogene rainforests, these fossils show a dynamic history in the evolution of tropical floras. This talk will explore recent findings of tropical plant fossils that reveal both the long-standing occurrence of modern tropical taxa, evidence of old-world linages that once lived in the New World, and the effects of the end-Cretaceous extinction event in tropical terrestrial ecosystems.
Monica Carvalho
University of Michigan
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EDGE Angiosperms: Integrating phylogenetic and extinction risk data for conservation prioritization in flowering plants
With biodiversity in rapid decline, and limited resources available for conservation action, the question of which species and regions should be prioritised for conservation is both critical and urgent. Global scale analyses of biodiversity distribution and conservation prioritisation have so far generally failed to account for plants, the structural and ecological foundation of virtually all terrestrial ecosystems. There are approximately 350,000 species of vascular plants known to science, the majority of which are vital for the survival of countless other species of plants, fungi, animals, and microorganisms that depend on them. With recent estimates showing that almost two in five (39%) vascular plants are threatened with extinction, determining which plant species are at risk and which threats they face is central to protecting not only these species, but entire ecosystems. Here, I will present the latest developments in the EDGE metric (Evolutionarily Distinct and Globally Endangered), which uses phylogenetic and extinction risk data, and the preliminary work we have done on Gymnosperms using this approach. I will also discuss the ongoing development of the first global conservation prioritisation for flowering plants, the EDGE Angiosperms prioritisation list, which will facilitate the integration of flowering plants into global biodiversity analyses on an equal footing with tetrapods, thus addressing an imbalance which has undermined conservation actions for decades.
Félix Forest
Ecosystem Stewardship,
Royal Botanic Gardens, Kew
The Origin and Evolution of Neotropical Biodiversity
Few issues have been as intriguing and exciting to scientists as the origin and evolution of Neotropical biodiversity. Yet relatively little is still known about the evolutionary relationships among Neotropical organisms and the factors that have shaped the high species diversity found in this region. It is clear that historical and ecological factors have played key roles in species diversification and the assembly of biotas, calling for multi-disciplinary studies. Integrative approaches, including information from systematics, ecology, evolution, geology, paleontology, and climatology, are critical for a better understanding of current diversity patterns and drivers. To understand the history of Neotropical biodiversity, we conduct detailed studies focused on key Neotropical lineages, as well as broad-scale studies that look at biotas as a whole. Such a detailed understanding of organisms and biotas provides crucial information to better conserve and sustainably use Neotropical biodiversity.
Lúcia G. Lohmann
Universidade de São Paulo
"Evolutionary Hologenomics"
Host-associated microorganisms are increasingly recognized as not just playing functions related to pathogenic diseases and food digestion, but can have a remarkably range of effects on their host lives. This raises the obvious question – if we are trying to understand the genetic basis of life, and how it has evolved, what are we missing if we remain focused on the host alone. In this talk I introduce evolutionary hologenomics, an emerging discipline that ultimately aims to revisit how life is shaped by the union of a host and its microbes – not just at the local scale but in the much bigger context. In doing so I present examples of not only some of the diverse processes that require consideration of both partners to understand them fully, but also present hypotheses of currently unrecognized relationships that present alternate explanations for a range of adaptive processes.
Thomas Gilbert
Section for Hologenomics, University of Copenhagen
Linking patterns and processes across scales: a case study with Neotropical hummingbirds
A fundamental challenge for ecology and evolution is connecting broad scale biogeographical and macro-evolutionary mechanisms with local scale patterns of diversity. Biogeographic patterns of species relatedness and trait similarity suggest that niche conservatism, limiting similarity and competitive exclusion of closely related species are important mechanisms structuring Neotropical hummingbird communities. However, the precise role of these mechanisms in influencing local assemblage structure is difficult to infer from biogeographic patterns alone. Using our broad scale results as a guide, we developed local scale experiments and quantified hummingbird-plant interactions to better understand the mechanisms underlying both local and biogeographic patterns of diversity. In addition, we considered how hummingbird physiological constraints might influence these local patterns. Our work provides an initial link between patterns established by broad scale biogeography and mechanisms learned from local scale community and physiological ecology.
Febrero 8
Catherine H. Graham
Swiss Federal Research Institute
Phylogenomics and major evolutionary transitions
Comparative genomics have the power to provide new insights into major evolutionary transitions. A robust phylogenetic framework remains crucial for the comparative approach, yet it is often blurred by fast diversification following major innovations. This talk covers progress on the phylogeny and genomic basis of water-to-land transitions in vertebrates and plants and the origin of photosynthetic organelles by symbiosis.
Febrero 22
Iker Irisarri
University of Göttingen
The role of knox (knotted-like homeobox) genes in leaf shape diversity
Plant architecture results from the activity of shoot meristems. KNOX genes are turned off when leaves initiate from the meristem, setting up a proximal-distal polarity with KNOX expression at the leaf base and loss of KNOX at the distal tip. In maize, the KNOTTED1 gene, produces dramatic phenotypes when misexpressed in the leaf. In species with dissected leaves, KNOX gene expression returns during leaf development, creating leaflets. Thus, KNOX genes are responsible for many aspects of leaf diversity.
Sarah Hake
University of California - Berkeley
Exploration of fungal diversity using a single cell sequencing approach
In order to develop a fully resolved fungal tree of life we need to include all fungal taxa, yet many important species and lineages of fungi have never been cultivated. We are exploring how single cell sequencing can overcome this limitation and produce novel insights into fungal life cycles and symbiotic interactions.
Marzo 22
Timothy James
University of Michigan
Global Impacts of the Amphibian-Killing Fungus:a Functional Genomic View
Two fungal pathogens have had devastating effects on amphibian biodiversity at a global scale. I will review some of these impacts and explore, through functional genomic studies, the mechanisms of host-pathogen interactions that underlie resistance or susceptibility in host species.
29 de marzo
Kelly Zamudio
University of Texas at Austin
Phylogenetics of ray-finned fishes (Actinopterygii) in the 21st century
The emergence of a new phylogeny of ray-finned fishes at the turn of the twenty-first century marked a paradigm shift in understanding the evolutionary history of half of living vertebrates. I review how the new ray finned fish phylogeny radically departs from classical expectations formulated in the 20th century based on morphology. I focus on evolutionary relationships that span the backbone of ray-finned fish phylogeny, from the earliest divergences among teleosts and nonteleosts to the resolution of major lineages of Percomorpha. Throughout, I feature advances gained by the new phylogeny toward a broader understanding of ray-finned fish.
Abril 19
Thomas Near
Yale University
Plant evolution at different phylogenetic, temporal, and spatial scales
In this talk, I will highlight our recent and ongoing work on patterns and processes of plant evolution, with a focus on two interrelated topics: ii how the history and the features of the landscape influence plant diversification, and ii) what plant species might be and how they form and are maintained in nature.
Felipe Zapata
University of California Los Angeles
Cuatro Ciénegas y la montaña que guardó la vida
Cuatro Ciénegas en Coahuila es un oasis irrepetible, por razones geológicas ahí se guardaron los sedimentos marinos desde el proterozoico (y tal vez desde el arqueano) hasta el cretácico, momento cuando se levantó la sierra de San Marcos y pinos, aislando esta “isla” del resto del mar. Lo que permitió que la microbiota profunda continuara formando estromatolitos en la superficie, es la presencia del magma en las profundidades de dicha sierra. El tiempo y el aislamiento nos explican el porqué este sitio lleno de pozas con tapetes microbianos y estromatolitos es el sitio más diverso que conocemos.
Valeria Souza
Instituto de Ecología - UNAM