Abstract Detail

Ericaceae: Systematics, Ecology and Evolution

Puente, Caroline [1], Crayn, Darren [2], Freyman, William [3], Potter, Benjamin [4].

Phylogeny and biogeography of the Epacridoideae (Ericaceae).

The Ericaceae subfamily Epacridoideae includes 37 genera and ca. 640 species primarily distributed across Australasia, with centres of diversity in southwestern and southeastern Australia. The group exemplifies many of the controversies in the historical biogeography of Australasia regarding hypotheses of long-distance dispersal and Gondwanan vicariance. Here, we set out to test these hypotheses using a combination of time-calibrated phylogenetics and ancestral area reconstructions. While a vicariance scenario would predict patterns of near-simultaneous divergences in multiple lineages, long-distance dispersal would predict independent asynchronous divergences. We present a densely sampled 5-gene time-calibrated phylogeny including representatives from all genera and ca. 65% of the species in the Epacridoideae. Competing hypotheses of dispersal and vicariance were tested using stochastic mapping of the dispersal-extinction-cladogensis (DEC) model of biogeographic range evolution. Our results under different schemes consistently suggest that the multiple disjunctions between the Australian, New Zealand, and New Caledonian clades are independent events and not older than the Late Miocene. They also indicate that the western and eastern Australia clades diverged during the Early to Middle Miocene, coinciding with the emergence of the Nullarbor Plain. Thus, we estimate that the current distributional patterns of the epacrids can be explained by a combination of both vicariant and long-distance dispersal events.

1 - Australian Tropical Herbarium, Sir Robert Norman (E2) Building, PO Box 6811, Cairns, QLD, 4870, Australia
2 - Australian Tropical Herbarium, Sir Robert Norman (E2) Building, Po Box 6811, Cairns, QLD, 4870, Australia
3 - 1815 JFK Blvd Apt 834, Philadelphia, PA, 19103, United States
4 - University of Auckland, School of Biological Sciences, Thomas Building, 3a Symonds Street, Auckland, 1010, New Zealand

Keywords:
Australasia
biogeography
Ericaceae
molecular phylogenetics.

Presentation Type: Colloquium Presentations
Session: CO06, Ericaceae: Systematics, Ecology and Evolution
Location: Tucson D/Starr Pass
Date: Tuesday, July 30th, 2019
Time: 10:45 AM
Number: CO06011
Abstract ID:916
Candidate for Awards:None