NSF Postdoctoral Fellowship in Biology: Hybridization and the dynamics of morphological and genetic differentiation during evolutionary radiation

Lichter Marck, Isaac H, Venice CA

Investigators

Abstract

Fellow's name: Isaac Lichter Marck Proposal number: 2209393 Research title: Hybridization and the dynamics of morphological and genetic differentiation during evolutionary radiation Sponsoring scientist(s) and host institution(s): Dr. Felipe Zapata, University of California, Los Angeles & Dr. Rosita Scherson, University of Chile This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. Variation is the raw material for the process of evolution by natural selection, but where does natural variation come from? One hypothesis is that gene exchange between different species, or hybridization, could bring foreign genes into the gene pool and boost the variation available for evolution. This research will test the role of hybridization in providing the raw material for evolution in a diverse tribe of sunflowers called the rock daisies (Perityleae) found in mountains, islands, and deserts in North and South America. The research will develop statistical tools to understand when hybrids have formed during the recent radiation of the rock daisies using genetics, morphology, and ecology. In documenting the mechanisms generating diversity in this group, the fellow will gain valuable training in hybridization studies and bioinformatics as well as developing teaching modules for free dissemination about how we can better preserve biodiversity for future generations. Hybridization may play a fundamental role during evolutionary radiations through two pathways: by seeding variation via hybridization at the onset (the hybrid origins hypothesis) and by generating variability through reticulation among members of a radiating clade (the syngameon hypothesis). The fellow will test these hypotheses during the radiation of the rock daisies at three scales in which shifts into new adaptive zones occurred. At the sub genome level, the fellow will test whether hybridization arose prior to trans-oceanic dispersal to Guadalupe Island in an allopolyploid island endemic plant (Nesothamnus incanus). At the population level, the fellow will investigate whether hybrid origins of South American rock daisies boosted variation prior to long-distance dispersal, facilitating intercontinental invasion success. In a diverse clade of interest, the fellow will integrate microevolutionary and macroevolutionary data from 57 taxa in the genus Laphamia into a time calibrated framework to reconstruct the dynamics of hybridization, genetic differentiation, and morphological disparification during a biome shift into the North American Deserts. The fellow will gain valuable training in phylogenetic methods and international interdisciplinary collaboration. To broaden participation in science, the fellow will undergraduates, develop bilingual teaching modules in English and Spanish, and distribute novel tools to fellow researchers. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.