Tidepool Copepod

Incipient Speciation

Tigriopus californicus populations at the southern end of the species range show unusually strong levels of reproductive isolation from more northern populations, with strikingasymmetry between reciprocal crosses (Ganz & Burton 1995 and D. Peterson, unpub data).  That is, when females from the southernmost locations are crossed to northern males they produce no F1, while southern males crossed with northern females produce F1 but no F2.  We are honing in on the exact geographic location where incompatibility patterns change, and are focusing on the genetic mechanisms driving these patterns.