Mon, Feb 26, 2018
Presenter: Jamie Kostyun, PhD
Title: "The Developmental Genetic Basis and Evolutionary Consequences of Floral Diversity in Jaltomata (Solanaceae)"
"Understanding the generation and maintenance of biodiversity – one of the key goals of evolutionary biology – requires addressing two fundamental processes: the evolution of phenotypic novelty and diversity, and lineage diversification (i.e. speciation and extinction). My broad research interests encompass these two processes and how they might interact to produce existing patterns of diversity. I focus on floral variation within the angiosperms, as floral traits are critical for both ecological interactions and reproductive success, and have long been implicated as a key innovation driving the extensive species richness of this clade. Species of my study system, Jaltomata (Solanaceae), are native to the Neotropics and encompass a surprising amount of floral trait variation, such as overall floral shape and size, petal and nectar color, and nectar volume, despite being relatively recently diverged (
Mon, Mar 5, 2018
Presenter: Julian Damahek, Ph.D.
Title: Understanding Nitrogen Uptake in the Ocean Using Metatranscriptomics, or: How I Learned to Stop Worrying and Love the Command Line.
Determining the diversity and metabolic activity of microbes in the environment is a critical part of understanding how nutrients cycle in ecosystems. Nitrogen is a particularly interesting nutrient for biologists: it often limits productivity at regional scales, but can also drive local ecosystems down the spiral of eutrophication when present in excess, and nearly all nitrogen-cycling reactions in any environment are due to microbial activity. In this talk, I will describe recent work using computational tools to analyze metagenomic and metatranscriptomic data from the Amazon River and its plume to better understand how microbes assimilate and oxidize ammonium (NH4+) in rivers and the coastal ocean. The prevalence of high-throughput sequencing has turned microbial ecology into a field that combines tools and theories from “traditional” microbiology and ecology with those of computational and data sciences. One part of the talk will focus on reconstructing “environmental genomes” by binning metagenomic contigs, focusing on a novel genome assembly of an ammonia-oxidizing archaeon from the river. The second half of the talk will describe targeted gene- and transcript-specific analyses of a key ammonium uptake gene, demonstrating how metatranscriptomic data can be used to interrogate which microbial populations are expressing important biosynthetic genes in along the riverine/coastal gradient. In all, these data show how focused analyses of massive sequence libraries can compliment culture-based microbiology and nutrient biogeochemistry to augment our knowledge of microbial nutrient cycling in aquatic ecosystems.