A top executive responsible for overseeing the research and scientific efforts of the nation’s largest autism advocacy group is moving on.

Autism Speaks said Thursday that Geraldine Dawson, the group’s chief science officer for the last five years, is leaving. Dawson is being replaced by Robert Ring who has served as vice president of translational research for the organization since 2011.

Dawson is leaving to take a position at Duke University where she will conduct research and do clinical work as a professor of psychiatry and behavioral sciences and serve as director of the university’s autism center. She was Autism Speaks’ first chief science officer.

Records indicate that Autism Speaks’ science portfolio accounts for the largest slice of the nonprofit’s budget at over $24 million in 2011, according to the organization’s tax filing for that year, the most recent that’s publicly available.

As chief science officer, Dawson was the highest paid employee at the nonprofit, earning more than $440,000 in 2011, the tax filing indicates.

In addition to her role at the nonprofit, Dawson also served as a professor of psychiatry at the University of North Carolina at Chapel Hill and she is a member of the Interagency Autism Coordinating Committee, or IACC, a federal autism advisory committee.

Ring initially came to Autism Speaks from Pfizer where he was head of the pharmaceutical giant’s autism research unit.

As of last year, Ring also leads a secondary nonprofit known as DELSIA which was created by Autism Speaks to bring innovations benefiting people with autism to the commercial market.