Abstract Detail

Systematics Section / ASPT

Givnish, TJ [1], Pires, JC [4], Graham, SW [2], McPherson, MA [12], Prince, LM [9], Patterson, TB [1], Rai, HS [12], Roalson, ER [7], Evans, TM [3], Hahn, HJ [5], Millam, KC [1], Meerow, AW [8], Molvray, M [6], Kores, P [6], O'Brien, HE [12], Kress, W. John [10], Hall, Jocelyn [11], Sytsma, Kenneth J. [1].

Phylogeny of the monocotyledons based on ndhF sequence variation: evidence for widespread concerted convergence.

We present a well-resolved, highly inclusive phylogeny for monocots based on ndhF sequences for nearly 300 taxa, and use it to test the hypotheses that net venation and fleshy fruits have undergone concerted convergence and represent independent but often concurrent adaptations to shaded conditions. Asparagales are sister to the commelinids, with Liliales and Pandanales sister to this larger group in the strict consensus; Dioscoreales and Pandanales are sister to each other, and then to Liliales in the bootstrap majority-rule tree. Our data demonstrate that net venation arose at least 26 times and was lost eight times over the past 90 million years; fleshy fruits arose at least 21 times and disappeared 11 times. Both traits show a highly significant pattern of concerted convergence (P < 10^-9), arising 16 times and disappearing four times in tandem. This phenomenon appears driven by even stronger tendencies for both traits to evolve in shade and be lost in open habitats (P < 10^-13 to 10^-29). The frequency of adaptive change per clade in both characters has declined exponentially over the past 90 million years, perhaps reflecting the filling of open and closed habitats on continents around the world during the explosive adaptive radiation of the monocots. These patterns are among the strongest ever demonstrated for evolutionary convergence in individual traits and the repeatability of evolution, and the strongest evidence yet uncovered for concerted convergence.

1 - University of Wisconsin-Madison, Botany, 430 Lincoln Drive, Madison, Wisconsin, 53706-1381, USA
2 - University of British Columbia, UBC Botanical Garden and Centre for Plant Research, 6804 SW Marine Drive, Vancouver, British Columbia, V6T 1Z4, Canada
3 - Hope College, Biology Department, Peale Science Center, 35 East 12th St., Holland, Michigan, 49400-9000, USA
4 - University of Wisconsin-Madison, Horticulture, 1575 Linden Drive, Madison, Wisconsin, 53706, USA
5 - Georgetown University, 108 White-Gravenor, Washington, DC, 20057, USA
6 - Moorpark College, Biology, Moorpark, California, 93021, USA
7 - Washington State University, School of Biological Sciences, P.O. Box 644236, Pullman, Washington, 99164-4236
8 - USDA-ARS-SHRS and Fairchild Tropical Botanical Garden, National Germplasm Repository, 11935 Old Cutler Rd., Coral Gables, Florida, 33156, USA
9 - Rancho Santa Ana Botanical Garden, 1500 North College Avenue, Claremont, California, 91711-3157, USA
10 - Smithsonian Institution, Department of Botany, MRC166, National Museum of Natural History, P.O. Box 37012, Washington, DC, 20013-7012, USA
11 - Harvard University, Organismic and Evolutionary Biology, 26 Oxford St., Cambridge, Massachusetts, 02138, USA
12 - University of Alberta, Department of Biological Sciences, CW 405 Biological Sciences Building, Edmonton, Alberta, T6G 2E9, Canada

Keywords:
adaptive radiation
concerted convergence
adaptation.

Presentation Type: Paper
Session: 2-8
Location: Cottonwood A (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 9:45 AM
Abstract ID:545