Poinar earned a BS and MS at Cornell University, and remained there for his doctoral studies, receiving a PhD in biology in 1962.

He spent many of his years of research at University of California, Berkeley in the Department of Entomology, Division of Insect Pathology.

In 1992 a team consisting of Poinar, his wife entomologist Roberta Poinar, his son Hendrik, and Dr. Raúl J. Cano of California Polytechnic State University successfully extracted insect DNA from a Lebanese weevil in amber that was 125 million years old, collected by Raif Milki in Lebanon.

Named Strychnos electri, after the Greek word for amber (electron), the flowers represent the first-ever fossils of an asterid.

[3] The paper describes a flower of an ancestral milkweed plant, which was named Discoflorus neotropicus, and a termite carrying a pollinium, all covered in Dominican amber.