Macroevolutionary studies of trait evolution are incomplete without the integration of speciation and extinction rates. The frequency of a character state on the tips of a phylogenetic tree is not only the result of the trait change per se but is also a function of lineage diversification if the character state is linked to speciation and extinction rates. In this talk, I will show three different examples of trait evolution linked to diversification.

The nucleus is extensively studied for its role in gene expression. However, growing evidences indicate that the biophysical properties of this organelle participate in cellular functions such as cell migration and pathogen killing; two processes critical for immune response. In this talk, I will describe our discovery of how immune cells undergoing confined migration squeeze their nuclei through narrow pores by forming a dense perinuclear actin network.

Mechanical deformations of DNA are ubiquitously part of universal biological processes involved in the transduction of genetic information. Although the average compliance of DNA to accommodate such deformations has been extensively measured, biophysical measurements of DNA have never been conducted on a genome-wide scale. Consequently, we lack experimental understanding of the extent to which the local mechanical properties of DNA vary with sequence along entire genomes, and how such variations modulate the energetics of diverse biological processes.

How simple tissues give rise to geometrically complex organs with robust shapes and functions is a fundamental question in biology with important implications in disease and translational medicine. The current mechanistic framework explains how upstream genetic and biochemical information pattern cellular mechanics and thereby tissue dynamics. In this framework, the main driving force is cell-intrinsic and generated by actomyosin contractility.

The long-term goal of the Kucenas Lab is to fundamentally understand the cellular and molecular mechanisms that mediate neural-glial and glial-glial interactions during nervous system development and injury/regeneration. Using Danio rerio (zebrafish) as a model system, we combine genetic and pharmacological perturbation, single cell manipulation, laser ablation/axotomy, small molecule screening, and in vivo, time-lapse imaging to directly and continuously observe glial cell origins, behaviors, and interactions in an intact vertebrate.

Population variation within Western Fence Lizards in the Puget Sound
By: Hayden Davis (Leaché Lab)

The role physical asymmetry plays in Drosophila neural stem cells
By: Melissa Delgado (Cabernard Lab)

Classroom practices affect student behavior, and by extension, their learning. Through studying how students discuss clicker questions in active learning classrooms, we have found that students rarely use reasoning when answering in-class questions. However, their use of reasoning increases when they are cued to use reasoning by instructors or peers, or when under pressure of accountability. Can students transfer in-class group practices to individual assessment opportunities that require reasoning and logic?