Chromosome Numbers In Compositae Vii: Astereae Iii

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142139/1/ajb207543.pd

EVIDENCE OF DIFFERENT ADAPTATIONS OF FLOWER COLOR VARIANTS OF ENCELIA FARINOSA (COMPOSITAE)

Volume: 21Start Page: 49End Page: 6

A SYSTEMATIC AND BIOGEOGRAPHIC REVIEW OF RAILLARDIOPSIS [RAILLARDELLA] MUIRII (ASTERACEAE: MADIINAE), WITH SPECIAL REFERENCE TO A DISJUNCT CALIFORNIA COAST RANGE POPULATION

Volume: 37Start Page: 43End Page: 5

Chloroplast DNA Evolution and Adaptive Radiation in the Hawaiian Silversword Alliance (Asteraceae-Madiinae)

Volume: 77Start Page: 96End Page: 10

Chromosome Numbers In Compositae. Iv. Ambrosieae

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141318/1/ajb206651.pd

NATURAL HYBRIDIZATION BETWEEN SPECIES OF AMBROSIA AND HYMENOCLEA SALSOLA (COMPOSITAE)

Volume: 43Start Page: 15End Page: 2

Natural selection maintains species despite frequent hybridization in the desert shrub Encelia.

Natural selection is an important driver of genetic and phenotypic differentiation between species. For species in which potential gene flow is high but realized gene flow is low, adaptation via natural selection may be a particularly important force maintaining species. For a recent radiation of New World desert shrubs (Encelia: Asteraceae), we use fine-scale geographic sampling and population genomics to determine patterns of gene flow across two hybrid zones formed between two independent pairs of species with parapatric distributions. After finding evidence for extremely strong selection at both hybrid zones, we use a combination of field experiments, high-resolution imaging, and physiological measurements to determine the ecological basis for selection at one of the hybrid zones. Our results identify multiple ecological mechanisms of selection (drought, salinity, herbivory, and burial) that together are sufficient to maintain species boundaries despite high rates of hybridization. Given that multiple pairs of Encelia species hybridize at ecologically divergent parapatric boundaries, such mechanisms may maintain species boundaries throughout Encelia

Natural selection maintains species despite frequent hybridization in the desert shrub Encelia.

Natural selection is an important driver of genetic and phenotypic differentiation between species. For species in which potential gene flow is high but realized gene flow is low, adaptation via natural selection may be a particularly important force maintaining species. For a recent radiation of New World desert shrubs (Encelia: Asteraceae), we use fine-scale geographic sampling and population genomics to determine patterns of gene flow across two hybrid zones formed between two independent pairs of species with parapatric distributions. After finding evidence for extremely strong selection at both hybrid zones, we use a combination of field experiments, high-resolution imaging, and physiological measurements to determine the ecological basis for selection at one of the hybrid zones. Our results identify multiple ecological mechanisms of selection (drought, salinity, herbivory, and burial) that together are sufficient to maintain species boundaries despite high rates of hybridization. Given that multiple pairs of Encelia species hybridize at ecologically divergent parapatric boundaries, such mechanisms may maintain species boundaries throughout Encelia