Abstract Detail

Population Genetics/Genomics

Williams, Tanisha [1], Antoine, Ariel [2], McDonnell, Angela [3], Cantley, Jason [4], Jobson, Peter [5], Martine, Christopher [1].

Population genomics and the influence of biogeographic barriers in Templetonia hookeri (Fabaceae), an endemic legume of the Australian Monsoon Tropics.

In order to understand contemporary species distributions, more knowledge is needed to elucidate the roles of how genomic variation and structure, coupled with the impacts of biogeographic barriers, shape present day occurrences. The biodiversity and climatic histories of the Australian Monsoon Tropics (AMT) provides a unique system for investigating evolutionary processes driving species distributions and diversification. The AMT is a topographically and climatically diverse tropical biome in northern Australia where well-known biogeographic barriers have been proposed as drivers of distributional patterns leading to closely-related taxa that are geographically isolated and morphologically distinct. The barriers and associated microhabitat variation are thought to have facilitated the large number of narrowly endemic lineages of angiosperm taxa found throughout the AMT. However, the opposite pattern has been observed in the endemic legume Templetonia hookeri. T. hookeri is broadly distributed across several well-known biogeographic barriers found in the AMT and appears to be morphologically stable across its range. Population genomic methods were used to analyze the genetic diversity and population structure of T. hookeri, and assess whether biogeographic barriers are influencing the distribution pattern observed. We used a genotyping-by-sequencing (GBS) approach to assess the status of 13 populations of T. hookeri across the “Top End” of the Northern Territory. Results show that populations are highly isolated with reduced genetic diversity, exhibit high levels of inbreeding, and are strongly structured by geography. Genetic clustering methods also correspond significantly with known biogeographic boundaries. The significant lack of genetic diversity within each population, coupled with the support for highly geographically structured populations, provides evidence that although populations may look morphologically similar, they are genetically distinct. This work is part of a broader project highlighting the role of AMT sandstone escarpments as habitat refugia for angiosperms during the Last Glacial Maximum, the first attempt to test for the effects of multiple biogeographic barriers across multiple lineages of AMT angiosperms. 

1 - Bucknell University, Biology, 1 Dent Drive, Lewisburg, Pennsylvania, 17837, United States
2 - Bucknell University , Biology, 1 Dent Drive, Lewisburg, PA, 17837, USA
3 - Chicago Botanic Garden, Science Dept., 1000 Lake Cook Road, Glencoe, IL, 60022, United States
4 - San Francisco State University, Biology, 1600 Holloway Ave, SF State University Biology Department, Hensill Ha, San Francisco, CA, 94132, United States
5 - Northern Territory Herbarium, Alice Springs, NT, AU

biogeographic barriers
genetic diversity
population genetics

Presentation Type: Oral Paper
Session: POPGEN2, Population Genetics/Genomics II
Location: Virtual/Virtual
Date: Thursday, July 30th, 2020
Time: 4:00 PM
Number: POPGEN2005
Abstract ID:387
Candidate for Awards:Margaret Menzel Award

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