Project title: Phylogeography of North American desert species of the genus Chenopodium
Founded by: MŠMT ČR (Ministry of Education, Youth and Sports)
Program: INTER-ACTION II
Duration: 2024 - 2028
Principal investigator: Prof. Mgr. Bohumil Mandák, PhD.
Project partner: College of Life Sciences, Brigham Young University, Provo, Utah, United States
Abstract:
The origin and historical dynamics of desert communities in North America have intrigued naturalists for over a century. Well-preserved macrofossils of flora and fauna in these ecoregions have allowed an understanding of the historical dynamics in desert communities. Leveraging fossil records and molecular data, this investigation focuses on two Chenopodium species, C. fremontii and C. neomexicanum agg., to explore hypotheses concerning their evolutionary trajectories. Specifically, the study aims to test the following hypotheses: H1) Neogene orogenic activity is responsible for interspecific differentiation, H2) Pleistocene glacial-interglacial cycles affected both species' intraspecific population divergence and demographic history. To test these hypotheses, the research will utilize coalescent statistical phylogeography approaches based on approximate Bayesian computation, comparing explicit scenarios of population divergence and demographic history considering late Neogene and Pleistocene time frames. We will test an additional hypothesis H3) The phylogeographic history of Chenopodium species is predicted by Pleistocene glacial-interglacial refugia, where Ecological Niche Modelling (ENM) will be employed to perform geographical projections of niche models on different palaeo-climatic scenarios for the late Pleistocene and then assess the linear associations between habitat stability and genetic diversity estimates, as predicted by climate refugia. Alternatively, the southern refugia hypothesis will be tested by estimating the linear associations of latitude with habitat stability and with the referred parameters of genetic diversity.