Abstract Detail

Systematics

Cardinal-McTeague, Warren [1], Wurdack, Kenneth [2], Gillespie, Lynn [3].

Biome shifts during the Late Miocene cooling period contributed to increased diversification rates in Euphorbiaceae vines.

Understanding the generation and maintenance of biodiversity is a central theme in evolutionary biology that aids our prediction of global responses to climate change. Presently, we are in a renaissance of clarifying the drivers of plant diversification and have identified several biotic and/or abiotic factors that contributed to increases in speciation and/or reductions in extinction. However, these impacts appear to be context specific and the relative contribution of multiple biotic/abiotic factors remains to be tested across additional groups. Here, I use plastid, nuclear ribosomal, and low-copy nuclear genes to produce a robust phylogeny to use as an evolutionary framework in a morphologically diverse lineage of Euphorbiaceae vines (tribe Plukenetieae). I demonstrate that neither biogeography nor multiple overlapping innovative traits (twining habit, stinging hair defences, and pseudanthial inflorescences) contributed to increases in diversification of the tribe. Instead, transitions from wet tropical forests into drier open areas resulted in three independent diversification shifts in the tribe. These shifts coincide with the Late Miocene cooling period (c.10 Mya), and may have been aided by the expansion of drier open habitats during that time, particularly in Africa. This study supports that general drivers of plant diversification are context-specific, and that climate-mediated landscape/biome expansions had a significant impact on plant diversification.

1 - Université de Montréal, Institut de recherche en biologie végétale (IRBV), 4101 Sherbrooke Est, Montreal, QC, H1X 2B2, Canada
2 - Smithsonian Institution, Botany, MRC-166 National Museum Of Natural History, National Museum Of Natural History, MRC 166, PO Box 37012, Washington, DC, 20013, United States
3 - Canadian Museum Of Nature, PO Box 3443, Station D, Ottawa, ON, K1P 6P4, Canada

Keywords:
Euphorbiaceae
Acalyphoideae
Plukenetieae
twining habit
stinging hairs
pseudanthia
biome shifts
diversification.

Presentation Type: Oral Paper
Session: SYS1, Systematics I: Land plants, Gymnosperms to Rosids part 1
Location: Tucson H/Starr Pass
Date: Monday, July 29th, 2019
Time: 4:30 PM
Number: SYS1012
Abstract ID:735
Candidate for Awards:None