Concordance of genetic and subfossil evidence for the Holocene radiation of the Holarctic Eubosmina, 1998-2006

We investigated the evolutionary radiation of a freshwater zooplankter that possesses a mixed breeding system and a detailed, dated, subfossil record. We estimated the phylogenetic relationships among the proposed species with complete nicotinamide adenine dinucleotide dehydrogenase subunit 2 mitochondrial gene sequence variation. We sequenced 374 Eubosmina specimens representing 10 out of 11 distinct morphospecies from 86 water bodies in three separate Holarctic regions. As expected for a Holocene radiation, there was a lack of monophyly for the proposed species and rare sharing of derived haplotypes among some species. Nevertheless, the proposed species exhibited little or no sharing of mitochondrial deoxyribonucleic acid haplotypes. Moreover, the phylogenetic and haplotype network results revealed a radiation pattern that is concordant with the subfossil record‐with an older Bosmina (E.) longispina radiating into several new forms. Our results bolster the subfossil, morphometric, experimental, and within-population genetic evidence that the common arctic B. (E.) longispina has radiated into several incipient species during the Holocene.