Just moved to Copenhagen!
I am newly arrived at the Center for Macroecology, Evolution, and Climate at the University of Copenhagen. Surely, many new projects are soon to be added to this space. Evolution of dispersal ability in rails Rails are one of the most widespread avian lineages, capable of long distance migrations and colonizing the remotest Pacific islands. Yet, they have also achieved flightlessness more than any other bird group. Because of this remarkable plasticity in dispersal ability, I am using rails as a model group to test if selection for metabolic efficiency and reduced dispersal drives the observed "paradox" of insular speciation. Galliform phylogenomics The Galliformes, or landfowl, are a globally distributed bird group that is a model system for understanding diverse subjects such as sexual selection and domestication (e.g., chicken, quail). However, inferring the galliform phylogeny has proven problematic because it comprises multiple rapid radiations at various evolutionary depths, and because few fresh tissue resources are available in collections. For my current postdoc, I am using high throughput target-capture DNA sequencing (including historical samples) of ultra-conserved elements to resolve galliform relationships and evolutionary history. Specific projects in the works include global biogeography and evolution of vagility, examining the roles of sexual selection and ecological factors in galliform diversification, and determining if sexual dimorphism influences diversification rate. Practical empirical phylogenomics Phylogenomic inquiry in Galliformes has also led to important methodological insights. We have found that target-capture methods can be used effectively on historical museum specimens (albeit with reduced yields)— an important feature because many Galliformes are endangered and collection of fresh tissue is not possible. However, analyses of these historical samples have uncovered potential biases using some coalescent approaches where missing data drives spurious results with strong support. With careful marker selection to reduce bias, we have found this problem can be reduced and overcome, such that traditional concatenated and coalescent approaches produce concordant results. For the next 'methods' project, we are looking at the effects of alternative partitioning schemes on phylogenomic performance. Philippine phylogeography I have several ongoing projects using RAD sequencing to test classic models of speciation in island archipelagos. These new data demonstrate that complex colonization scenarios, periodic isolation, and introgression have produced complex genetic patterns. These data also largely support the idea that much of the cryptic variation first identified from mtDNA sequences is present throughout the genome, and that there is little to no gene flow between "cryptic" avian lineages. The real significance of this cryptic variation is not well understood. Phylogeographic studies of bird lineages also have strong conservation implications, as past taxonomic treatments drastically underestimate species diversity and alter perceived patterns of endemism— particularly on small islands. In the Philippines, molecular markers and plumage patterns from 20 avian lineages suggest that recognized species diversity is currently underestimated by as much as 75%— and this estimate doesn't consider cryptic variation, so it may still be conservative. Overlooked avian endemism and diversity in Peru Recent fieldwork in seldom-visited areas of south-central Peru has uncovered several new bird taxa and a wealth of new distribution records, suggesting that understudied areas such as eastern Ayacucho are unappreciated centers of avian endemism. This is a meaningful result because the region is entirely lacking in formal protected areas and human populations in the region are growing rapidly. |
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