Movie S2.

Relatively large male attempting to copulate. Female on top, male on bottom. The male’s abdomen is too long for sustained copulation. Dimorphism score = - 197μm..

Rapid experimental evolution of reproductive isolation from a single natural population

Scott M. Villa, Juan C. Altuna, James S. Ruff, Andrew B. Beach, Lane I. Mulvey, Erik J. Poole, Heidi E. Campbell, Kevin P. Johnson, Michael D. Shapiro, Sarah E. Bush, and Dale H. Clayton

PNAS. 2019. 116:13440-13445 DOI: 10.1073/pnas.1901247116