The November/December issue of the International Journal of Plant Sciences explores the current state of our knowledge of natural selection in plants.
"Plants were crucially important to Darwin's development of the theory of natural selection (six of his books were on plants)," writes Jeffrey Conner, a biologist at Michigan State University and guest editor of the issue. "Plants are still crucially important to the study of natural selection in the field."
The issue features reviews and original research articles that explore multiple aspects of this complex topic. A complete table of contents for the issue is available at http://www.journals.uchicago.edu/toc/ijps/current.
The Evolution of Self-Fertilization
The ability of some plants to self-fertilize has its advantages, especially in areas where there aren't many pollinating insects. But research by Susan Mazer from U.C. Santa Barbara and colleagues suggests that self-fertilization may not always be an evolutionary advantage in and of itself. Rather, it sometimes may evolve because it is linked to physiological traits that help plants deal with seasonal drought.
The researchers studied four closely related species of Clarkia, which belong to the Evening Primrose family. Two of the species are predominantly self-fertilizing (selfers); the other two are predominantly outcrossing, meaning they fertilize via pollen transfer from plant to plant. The research has found that the selfers have physiological traits (faster photosynthetic rates per area of leaf, for example) that appear to promote a more rapid life cycle. As a result, selfers produce flowers and begin the reproductive process weeks before their outcrossing counterparts, and before the onset of the late spring drought in the plants' native habitat.
In addition to avoiding the periods of most intense drought, the
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