Pattern and Process in the Evolution of Hawkmoth-Pollination

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McDade 9806840 Nocturnal hawkmoths (HMs) are important pollinators worldwide, especially of plants whose flowers are white, tubular, nectar-rich, strongly perfumed and bloom at night. This suite of floral characteristics has evolved repeatedly in Angiosperms and, in some cases, within plant families. To what extent does this floral morphological syndrome reflect historical trends within evolutionary lineages rather than adaptations to pollinators? Do HM-pollinated flowers typically evolve from other tubular flowers (e.g. those pollinated by hummingbirds), or can morphologically diverse ancestors give rise to this condition? Similarly, do lineages with HM-pollinated species give rise to alternative reproductive strategies, or are they evolutionary dead ends? How do these trends affect the conservation of HM-pollinated plants, many of which are rare or produce commercially important products? This research will address these questions by studying floral advertisements (color, shape, fragrance) and rewards (nectar) in several hawkmoth-pollinated plants and their close relatives in the potato (Solanaceae), evening primrose (Onagraceae), and four-oclock (Nyctaginaceae) families. The investigators will use laboratory and field assays to determine which among these traits are effective in attracting hawkmoths to flowers, and then study variation in these traits using chemical analytical and comparative statistical methods within an evolutionary context. These analyses of fragrance and nectar chemistry will yield especially novel results, given the rarity of such data in previous studies.