91̽»¨

Sperm cell shape differs dramatically among species, and in some cases differences in sperm shape and/or size can help new species evolve. That is, if the sperm and egg are different enough between two groups, fertilization cannot occur. Without fertilization, the groups become reproductively isolated and therefore are separate species.

This project focuses on a case where sperm size differences have repeatedly, independently, and quickly evolved between pairs of populations of the same species of Littorina (periwinkle).

The aim is to understand:
1) How this size difference develops
2) Whether the size difference causes reduced fertilization and
3) How slight reductions in fertilization success would impact the overall process of speciation

91̽»¨: Becky Cramer (emily.cramer@gu.se)