Welcome to the Olson Lab where we study how multicellular organisms evolve.
The long term goal of the laboratory is to understand the molecular and ecological basis of major evolutionary state transitions. The primary question my laboratory investigates is how did multicellular organisms evolve? Multicellular organisms are those we most commonly perceive in our “macro” environment, yet little is known about the molecular and ecological basis of multicellular evolution unknown.
To study the evolution of multicellularity, my laboratory uses green algae as a model system. The volvocacean algae have been an important “textbook” model for multicellular evolution for many years. The volvocales are an order of closely related, recently diverged algal species that range from unicellular to multicellular (Fig. 1). Well known member species include the unicellular algae Chlamydomonas reinhardtii and Volvox carteri.
Fig. 1: Morphology of key volvocales suggests stepwise evolution of multicellularity
The morphological and evolutionary progression of the volvocales suggests stepwise evolution of multicellularity, starting with colony formation between unicells (e.g. Gonium), then a stepwise progression of cell expansion, division of labor, specialization and tissue differentiation (e.g. Volvox). Despite their morphological differences, the genomes of Chlamydomonas and Volvox are remarkably similar, suggesting that multicellularity requires few genetic changes.
My laboratory is utilizing two key approaches for understanding the molecular basis of multicellular evolution. First, my laboratory is leading a consortium to sequence the genomes and determine the developmental transcriptional profiles of several key volvocales. Second, my laboratory is using a systems biology approach toward determining which genes are important for all steps of multicellularity. My laboratory is particularly interested in understanding how and why individual unicells formed groups of cooperative cells, termed colonialism. To do this we are focusing on Gonium (Fig. 1) as a model for colonial evolution.
Understanding how and why individual cells evolved into multicellular organisms is an important evolutionary question and is important for our understanding of how human bodies maintain organizational control over cells. For example, human cancer is a fundamental loss of control of the growth and division of cells within the tissues of the body. Many of the genes defective in human cancers have been identified, however little is known about how multicellular organisms evolved control over their individual constituent cells. Long term, research in my laboratory is aimed at understanding how organisms evolved regulatory pathways controlling cell growth, division, and differentiation so that new approaches to cancer treatment could be developed.