Florentine Rutaganira wants to use chemical tools to decipher the roles of key signaling networks in choanoflagellates, single-celled organisms that are the closest living relatives of animals. Choanoflagellates produce a large number of tyrosine kinases, molecular signals essential for intercellular communication in animals. The presence of these molecules in choanoflagellates suggests that signaling components needed to communicate between cells is evolutionarily ancient. Tyrosine kinases may regulate choanoflagellate colony formation. Rutaganira expects her studies will spark new understanding of animal development, physiology, and disease.