Research
Plants are adapted to their environment in many ways, affected by their evolutionary history and natural selection, as well as molecular and genetic drivers. Our group studies evolutionary ecology of plants at the interface of genetics and ecology. We are studying the evolution of flowers and how interactions with pollinators are shaping floral traits, as well as the genetic basis that underlie this process. We use a plethora of methods, including genetics, bioinformatics, field and greenhouse experiments and observations in wild populations.
Evolution of flower colour polymorphism
Phenotypic trait variation is the raw material of natural selection. Within-population flower colour variation can be a useful characteristic to understand fundamental evolutionary processes that create and maintain trait variation. Flower colour is traditionally considered an adaptation to pollinator visual perception. Most flowering populations are uniform in colour, while a minority exhibiting within-population colour variation. We use these colour-polymorphic species to study the drivers of phenotypic variation, and the how this variation is maintained. The research aims to reveal the role of multiple pollinators, as well as pollinators and antagonists or biotic and abiotic selection agents, in exerting balancing selection that may lead to flower colour polymorphism. This is studied in species with colour dimorphic, polymorphic or continuous colour variation.
Evolution and genetic basis of floral traits
Floral traits are important for the plant to communicate with its pollinators. Most plants are dependent on the pollinator for reproduction and therefore a tight evolutionary interaction between the two exists. Pollinators exert selection that optimize pollination by adjusting flower traits such as flower size, scent, shape and colour, according to its specific pollinator. However, environmental stresses, such as low water availability, may select for contrasting direction. For example, flower size increases as response to pollinator-mediated positive selection to increase advertisement, and decreases as response to drought-mediated selection, favoring small flowers with low water loss. Because of this dynamic interaction, flower traits exhibit a huge amount of variation. We study the molecular and genetic basis of floral trait variation by RNA sequencing, biochemical analysis and quantifying the genetic basis and the plastic response, of plants from wild populations. By comparing genetic variation to phenotype variation, we can identify the genetic basis and evolutionary trajectory of flower trait diversity.
Conservation ecology
Global biodiversity is threatened by several human-induced processes, including land use change and climate change. Climate change has already affected species distribution, altering the geographically suitable location. The future impact of this change is predicted to be extensive, resulting in species extinctions. In order to mitigate that, conservation efforts are being made, including species reintroductions, the intentional planting of an organism inside its native range or ecological niche. In Israel, more than 400 plant species are included in the Red List of endangered plants. We study the outcome of reintroduction trials, and test the role of ecological niche mapping on reintroduction success. We use species distribution models to predict the potential ecological niche in the face of climate change, and study the factors that facilitate sustainable reintroductions.
Phylogeography, speciation and taxonomy
Phylogeography is the study of how historical events, such as changes in geography and environment, have influenced species distribution. Speciation, the process of forming new species, is often influenced by these historical events. Our studies on the Royal Irises and the genus Prospero aim to provide insights into their speciation and taxonomy. We study the evolutionary history of the Royal Irises and the patterns of their divergence. We also study the phylogeny of Prospero, to find the origin of P. loess, a newly identified species. These studies contribute to our understanding of the complex processes that drive diversification in plants.
Funding by the American Iris Society Foundation
