Author : Ana María Bedoya
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (134 download)
Book Synopsis Evolution of Aquatic Plants in Rivers and Wetlands Across the Andes in Northern South America by : Ana María Bedoya
Download or read book Evolution of Aquatic Plants in Rivers and Wetlands Across the Andes in Northern South America written by Ana María Bedoya and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Northern South America is one of the most biodiverse regions on earth and understanding the causes and processes that have led to the assembly of this rich biota has been central to ecological and evolutionary investigations since Humboldt and Wallace. Given that northern South America is a geologically dynamic region consisting of a complex and heterogeneous landscape matrix, landscape change is viewed as a primary factor promoting species diversification. The Andean Cordillera is deemed responsible for triggering explosive radiations and increasing diversification rates in Neotropical taxa. All botanical investigations that have aimed to understand the role of landscape change on the evolution of the Neotropical flora have been restricted to terrestrial plants. However, fossil and stratigraphic data show that the uplift of the Andes not only resulted in the development of high-elevation tropical ecosystems, but also in changes in drainage basin reconfiguration through time. Aquatic plants are most diverse in the Neotropics. How did Andean uplift and drainage basin reconfiguration shaped the evolution of aquatic plants in rivers and wetlands across the Andes in northern South America? In this dissertation I aim to address this question and provide a novel perspective on the impact of landscape change on the evolution of the Neotropical flora, by using empirical data obtained from samples collected in the field from which I generate comprehensive genomic datasets and conduct phylogenetic, populations genetics, and biogeographical analyses. To investigate the impact of Andean uplift and drainage basin reconfiguration on river plant evolution, I use Marathrum foeniculaceum and Marathrum utile(Podostemaceae) as model systems. These are the only species living strictly in fast-flowing rivers across the Andes in northern South America. To explore how landscape change in northern South America shaped the evolution of plants in standing-water ecosystems such as wetlands, I study selected species of Ludwigia (Onagraceae). Ludwigia include amphibious and strictly aquatic plants restricted to standing-water ecosystems like flooded savannas, lakes and ponds. In Chapter 1, I generate plastome data for five species of Podostemaceae and analyze the structure of the chloroplast genomes in a comparative framework within the order Malpighiales. This chapter is an introduction to learning about the evolution of Podostemaceae. The results of this chapter show that plastid genomes in the family are among the smallest in the Malpighiales due to variation in length of the inverted repeats, gene loss, and intergenic region variation. The uncommon loss of a number of genes is reported and we suggest fast rates of evolution in the plastomes of Podostemaceae. In Chapter 2, I investigate how drainage basin formation linked to Andean uplift shaped the evolution of plants in fast-flowing aquatic ecosystems such as river-rapids and waterfalls. Specifically, I aim to 1) test if the geographical separation of drainage basins interrupted by the Andes and other topological units in northern South America limits gene flow and structures populations according to river drainages, 2) determine if the timing of divergence events in populations of the two species in northern South America correspond with the currently proposed timing of Andean uplift, and 3) provide a hypothesis for the pattern and timing of drainage basin separation. I conduct phylogenetic, population genetics, phylogenetic networks and divergence dating analyses of populations of M. foeniculaceum and M. utile located in river drainages across the Andes. Andean uplift isolated populations of Marathrum limiting gene flow. At the same time, drainage basin reconfiguration brought species in sympatry where hybridization occurs. I propose that the pattern of divergence of populations reflects the formation of river drainages, which was not complete until
