Robert Ellis Fellows

Dr. Robert Ellis Fellows, Jr., M.D., Ph.D., a devoted scientist, educator, and mentor whose work advanced the fields of physiology and endocrinology, passed away peacefully at home in Boulder, Colorado, on November 21, 2025. He was 92.
Born in Syracuse, New York, Robert devoted his life to understanding the workings of the human body and to inspiring others through science and education. He earned his A.B. from Hamilton College in 1955, his M.D., C.M. from McGill University Faculty of Medicine in 1959, and his Ph.D. from Duke University in 1969. His academic training laid the foundation for a career that combined rigorous scientific inquiry with a deep commitment to mentorship.
After completing residencies at The New York Hospital and the Royal Victoria Hospital in Montreal, Dr. Fellows began his academic career at Duke University, where he served as Assistant and then Associate Professor of Physiology.
In 1976, Dr. Fellows joined the University of Iowa, where he served as Chair of the Department of Physiology for more than two decades. During his tenure, he recruited numerous outstanding faculty and provided steadfast leadership marked by high standards, integrity, and care for others. Within the Carver College of Medicine, he made lasting contributions, including helping to launch the Neuroscience PhD Program and playing a pivotal role in bringing the highly successful NIH-funded Medical Scientist Training Program (MD/PhD) to Iowa-now thriving in its sixth decade. Through this work, he helped launch the careers of many physician-scientists and left an enduring mark on medical education.
Dr. Fellows was widely respected as both an accomplished scientist and a gifted, empathetic mentor. Known for maintaining rigorous expectations while offering encouragement and support, he approached challenges with curiosity and courage. Colleagues and trainees alike remember him as a thoughtful leader, trusted advisor, and generous friend.
His research focused on the cellular and molecular mechanisms of neuronal development and differentiation in the central nervous system, with particular emphasis on the interactions of endocrine and autocrine factors in supporting the functional maturation of cultured fetal brain neurons. His work shed light on the roles of growth-promoting peptides-especially insulin and insulin-like growth factors-in regulating gene expression during early development. His studies were widely published and supported by major NIH grants, contributing significantly to the fields of physiology and endocrinology.
Upon his retirement in 2008, Dr. Fellows was named Professor Emeritus.
Throughout his career, Robert was honored with numerous recognitions, including election to Alpha Omega Alpha at McGill University and Sigma Xi at Duke University, though he wore such honors lightly. What mattered most to him was discovery-and sharing that sense of discovery with others. Many remember the way his eyes would light up when a student grasped a difficult concept or when a new question opened the door to wonder.
Known for his intellect, integrity, and gentle humor, Robert approached science with curiosity and humility. Beyond the laboratory, he was a man of reflection and kindness who cherished time with his family, delighted in thoughtful conversation, and found joy in asking-and sometimes answering-the big questions of life. He was also adventurous, taking particular pleasure in testing his sailing skills under challenging conditions.
He is survived by his daughters, Kara Suzanne Fellows and Ariadne Fellows-Mannion; his grandchildren, Daisy Elizabeth Fellows and Rowan Fellows-Mannion; and his first wife, Alice Fellows. He was predeceased by his second wife, Karlen Kiger.
In lieu of flowers, donations in Robert's memory may be made to Planned Parenthood, of which he was a President's Circle member.
Dr. Fellows will be remembered for a life devoted to discovery, mentorship, and the quiet joy of helping others see the world more clearly through science. His legacy endures in the knowledge he helped build, the minds he shaped, and the many people who continue to be inspired by his example.