Ocean exposure and latitude drive multiple clines within the coastal perennial ecotype of the yellow monkeyflower, Mimulus guttatus

A key goal of evolutionary biologists is to understand how and why genetic variation is partitioned within species. In the yellow monkeyflower, Mimulus guttatus (syn. Erythranthe guttata), coastal perennial populations constitute a single genetically and morphologically differentiated ecotype compared to inland M. guttatus populations. While the coastal ecotype's distinctiveness has now been well documented, there is also environmental variation across the ecotype's range that could drive more continuous differentiation among its component populations.