We think of a sperm's mission as a lonely one, each one hoping to find and fertilize the egg before the rest of pack. In some species, however, sperm literally stick together in a grouping that gives them a competitive boost. How does this all-for-one attitude give sperm that edge? Biologist Heidi Fisher of Harvard University analyzed the behavior of clumping sperm from two different mouse species - one monogamous, one promiscuous - under microscope slides. One contained sperm from multiple promiscuous males; the other had sperm from multiple monogamous males.
展开▼
