Genetics / Microbiology / Polymorphism / Phylogeography / Medical Microbiology / Phylogeny / Seasonality / Mitochondrial DNA / Europe / Haplotypes / United States / Asia / Cluster Analysis / European / Cytochrome B Gene / Genetic Polymorphism / Sibling Species / LSU rDNA / Paramecium / DNA fragmentation / Phylogeny / Seasonality / Mitochondrial DNA / Europe / Haplotypes / United States / Asia / Cluster Analysis / European / Cytochrome B Gene / Genetic Polymorphism / Sibling Species / LSU rDNA / Paramecium / DNA fragmentation