Postdoctoral Fellow
Dispersal determines gene flow among populations. In plants, dispersal is conditioned by fruit characteristics. The way fruits disperse away from an individual plant is always stochastic. This is in part because fruit morphology is not uniform, fruits with different attributes will reach farther or shorter away. However, some plants appear to have fruits specifically apt to reach particular distances, being those short or long. In some cases, several kinds of such fruits coexist in the same plant. This phenomenon is called "heterocarpy", the production of several discrete fruit morphs of different form by a single plant. The different fruit morphs are often associated with differences in other reproductive traits, namely flower mating system and seed dormancy. The three syndromes (mating system, fruit shape and seed dormancy) are bet hedging mechanisms, and are expected to be under similar evolutionary constraints, although the evidence for this is contradictory. Heterocarpy thus constitutes an optimal system for the study of a) the emergence of threshold characters and b) the correlated evolution between dispersal and other traits. Theoretical models predict that heterocarpy can be a favorable strategy under heterogeneous environmental conditions. However, it is unclear how it can emerge, and how it did so in unrelated plat groups. I propose to synthesize the available information on heterocarpy and analyze its evolution. This will illustrate under which conditions discrete dispersal phenotypes emerge and how dispersal evolution interacts with the evolution of other important reproductive traits. Moreover, it will show what environmental conditions favor the different types of mating system, dispersal mechanism and seed dormancy.
Dispersal evolution in the angiosperms: the origin of heterocarpy
| PI(s): | Rafael F Rubio de Casas |
| Start Date: | 1-May-2010 |
| End Date: | 30-Apr-2012 |
| Keywords: | |
Dispersal determines gene flow among populations. In plants, dispersal is conditioned by fruit characteristics. The way fruits disperse away from an individual plant is always stochastic. This is in part because fruit morphology is not uniform, fruits with different attributes will reach farther or shorter away. However, some plants appear to have fruits specifically apt to reach particular distances, being those short or long. In some cases, several kinds of such fruits coexist in the same plant. This phenomenon is called "heterocarpy", the production of several discrete fruit morphs of different form by a single plant. The different fruit morphs are often associated with differences in other reproductive traits, namely flower mating system and seed dormancy. The three syndromes (mating system, fruit shape and seed dormancy) are bet hedging mechanisms, and are expected to be under similar evolutionary constraints, although the evidence for this is contradictory. Heterocarpy thus constitutes an optimal system for the study of a) the emergence of threshold characters and b) the correlated evolution between dispersal and other traits. Theoretical models predict that heterocarpy can be a favorable strategy under heterogeneous environmental conditions. However, it is unclear how it can emerge, and how it did so in unrelated plat groups. I propose to synthesize the available information on heterocarpy and analyze its evolution. This will illustrate under which conditions discrete dispersal phenotypes emerge and how dispersal evolution interacts with the evolution of other important reproductive traits. Moreover, it will show what environmental conditions favor the different types of mating system, dispersal mechanism and seed dormancy. Related products
Publications- Phylogenetic relationships and character evolution analysis of Saxifragales using a supermatrix approach Soltis DE, Mort ME, Latvis M, Mavrodiev EV, O'Meara BC, Soltis PS, Burleigh JG, de Casas RR (2013). Phylogenetic relationships and character evolution analysis of Saxifragales using a supermatrix approach. American Journal of Botany 100(5): 916-929. doi:10.3732/ajb.1300044 Note: This publication is also associated with Pamela Soltis's visiting scholar project (Title: Reconstructing the Great Tree of Life)
- Maternal effects alter natural selection on phytochromes through seed germination Donohue, K., Barua, D., Butler, C., Tisdale, T. E., Chiang, G. C. K., Dittmar, E. and Rubio de Casas, R. (2012), Maternal effects alter natural selection on phytochromes through seed germination. Journal of Ecology, 100: 750â757. doi: 10.1111/j.1365-2745.2012.01954.x
- Seed after-ripening and dormancy determine adult life history independently of germination timing Rubio de Casas, R. (2012). Seed after-ripening and dormancy determine adult life history independently of germination timing. New Phytologist, 194(3), 868-879.
- Forest restoration in a fog oasis: Evidence indicates need for cultural awareness in constructing the reference Balaguer, L., Arroyo-Garcia, R., Jimenez, P., Jimenez, M. D., Villegas, L., Cordero, I., Rubio de Casas, R., Fernandez-Delgado, R., Ron, M. E., Manrique, E., Vargas, P., Cano, E., Pueyo, J. J., Aronson, J. (2011). Forest restoration in a fog oasis: Evidence indicates need for cultural awareness in constructing the reference. PLoS ONE, 6(8), e23004.
- Sun and shade leaves of Olea europaea respond differently to plant size, light availability and genetic variation Rafael R. de Casas, Pablo Vargas, Esther Pérez-Corona, Esteban Manrique, Carlos GarcÃa-Verdugo and Luis Balaguer 2011 Sun and shade leaves of Olea europaea respond differently to plant size, light availability and genetic variation, Functional Ecology, volume 25, issue 4, pp. 802-812
- Temporal matching among diurnal photosynthetic patterns within the crown of the evergreen sclerophyll Olea europaea L. C. GRANADO-YELA, C. GARCIA-VERDUGO, K. CARRILLO, R. RUBIO DE CASAS, L. A. KLECZKOWSKI and L. BALAGUER 2011 Temporal matching among diurnal photosynthetic patterns within the crown of the evergreen sclerophyll Olea europaea L., Plant, Cell & Environment, volume 34, issue 5, pp. 800-810
- Germination, post-germination adaptation, and species ecological ranges. Donohue, K., R. Rubio de Casas, Liana Burghardt, Katherine Kovach, Charles Willis. 2010. Germination, post-germination adaptation, and species ecological ranges. Annual Review of Ecology and Systematics, Vol. 41: 293-319
