Abstract Detail



Reproductive Processes

Whitton, Jeannette [1], Hersh, Evan [2], Williams, Jennifer [3].

Demographic comparisons of sexual and apomictic populations of Townsendia hookeri (Asteraceae).

Sexual diploid and apomictic polyploid populations of Townsendia hookeri occupy distinct ranges in the Rocky Mountain foothills. Sexual diploids occur farther south, in Colorado and southern Wyoming, while apomictic polyploids range from southern Wyoming to southern British Columbia and Alberta. Apomicts are known to have originated repeatedly from sexual progenitors, and their successful spread has been hypothesized to be linked to a colonization advantage (Baker’s Law), but our observations in common gardens suggest that apomicts may match or exceed the performance sexuals even in the sexual range. Nonetheless, because these are long-lived perennials, it is difficult to extrapolate from the experimental gardens (for which we have 5 years of data) to a general understanding of persistence over generations. To address this, we conducted a demographic study of seven populations to determine whether there are consistent differences between reproductive types in their demographic transition rates and projected population growth rates. We then ask whether these differences can help explain the distribution and persistence of sexual and asexual populations.


1 - Department Of Botany, University Of British Columbia, 3529-6270 University Boulevard, Vancouver, BC, V6T 1Z4, Canada
2 - University of British Columbia, Botany, 3529-6270 University Boulevard, Vancouver, BC, V6T 1Z4
3 - University of British Columbia, Geography, 1984 West Mall, Vancouver, BC, V6T 1Z2

Keywords:
demography
polyploidy
Perennial
Apomixis
life history.

Presentation Type: Oral Paper
Number: 0007
Abstract ID:908
Candidate for Awards:None


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