title: Molecular hyperdiversity and evolution in very large populations.
abstract: The genomic density of sequence polymorphisms critically affects the sensitivity of inferences about ongoing sequence evolution, function and demographic history. Most animal and plant genomes have relatively low densities of polymorphisms, but some species are hyperdiverse with neutral nucleotide heterozygosity exceeding 5%. Eukaryotes with extremely large populations, mimicking bacterial and viral populations, present novel opportunities for studying molecular evolution in sexually reproducing taxa with complex development. In particular, hyperdiverse species can help answer controversial questions about the evolution of genome complexity, the limits of natural selection, modes of adaptation and subtleties of the mutation process. However, such systems have some inherent complications and here we identify topics in need of theoretical developments. Close relatives of the model organisms Caenorhabditis elegans and Drosophila melanogaster provide known examples of hyperdiverse eukaryotes, encouraging functional dissection of resulting molecular evolutionary patterns. We recommend how best to exploit hyperdiverse populations for analysis, for example, in quantifying the impact of noncrossover recombination in genomes and for determining the identity and micro-evolutionary selective pressures on noncoding regulatory elements.
authors.affiliation: Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada. asher.cutter@utoronto.ca
authors.forename: Asher D
authors.initials: AD
authors.lastname: Cutter
authors.forename: Richard
authors.initials: R
authors.lastname: Jovelin
authors.forename: Alivia
authors.initials: A
authors.lastname: Dey
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D040961:Genetic Drift; D049810:Genetic Speciation; D014644:Genetic Variation; D009154:Mutation; D011156:Population Density; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D012641:Selection, Genetic / Q000235:genetics*