Earth hosts millions of species, allowing energy and nutrients to flow through the ecosystem and creating a vital environment for life to thrive. How did this diversity of life develop on Earth? This project addresses this fundamental question in cell and developmental biology by examining changes in the developmental programs of echinoderms, marine organisms such as sea urchins and sea stars, as a model system. Echinoderms are ideal models because embryos from each species are accessible and show gradual changes in their developmental programs depending on their evolutionary distances. For example, sea urchins are considered more derived than sea stars within echinoderms, with an evolutionary divergence estimated around 500 million years ago. The research focuses on a cell type called micromeres, which is unique to sea urchins and absent in other echinoderms. Micromeres act as a signaling center, significantly altering the developmental program in the sea urchin embryo. The research aims to understand how these unique cells evolved and their potential role in species divergence, therefore, seeking to explore the essential mechanisms that allow Earth to host millions of living organisms, including humans. Additionally, the project emphasizes outreach: sharing findings through laboratory tours, mentoring local students and teachers, and engaging undergraduate students in research. These efforts aim to promote scientific interest at various levels throughout the year. Mosa