Elisabeth S. Vrba (born May 17, 1942) is a paleontologist at Yale University who developed the turnover-pulse hypothesis.

Vrba studied zoology and mathematical statistics at the University of Cape Town to earn her undergraduate degree.

She is well known for developing the turnover-pulse hypothesis, as well as coining the word exaptation with colleague Stephen Jay Gould.

Gould died in 2002,[4] but their theory has been widely referenced in recent years in popular science writing.

[5][6] Vrba and Gould's theory has also been criticized in recent years by scholars who assert that genetic traits are pressured by multiple factors, making it challenging to determine when adaptation or exaptation is at play.