Pluvial Drainage Patterns and Holocene Desiccation Influenced the Genetic Architecture of Relict Dace, Relictus solitarius (Teleostei: Cyprinidae)

• Published in: PloS one 2015-09, Vol.10 (9), p.e0138433-e0138433
• Main Authors: Houston, Derek D, Evans, R Paul, Shiozawa, Dennis K
• Format: Article
• Language: English
• Subjects: Animals; Base Sequence; Biodiversity; Biological Evolution; Biology; Cyprinidae; Cyprinidae - classification; Cyprinidae - genetics; Deoxyribonucleic acid; Desiccation; Divergence; DNA; DNA sequencing; DNA, Mitochondrial - analysis; DNA, Mitochondrial - genetics; DNA, Mitochondrial - isolation & purification; Drainage; Drainage patterns; Drying; Endangered & extinct species; Evolution; Fish; Genetic diversity; Genetic structure; Genetic Variation; Geology; Haplotypes; Holocene; Holocene paleogeography; Integrated software; Lakes; Last Glacial Maximum; Mitochondrial DNA; Molecular Sequence Data; Nevada; Nucleotide sequence; Phylogeny; Pleistocene; Populations; Raphus solitarius; Relictus solitarius; Sequence Analysis, DNA; Teleostei; Valleys
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0138433

Changing drainage patterns have played a significant role in the evolution of western North American aquatic taxa. Relict dace, Relictus solitarius, is a Great Basin endemic cyprinid with a native range that is restricted to four valleys in eastern Nevada. Relictus solitarius now occupies spring systems that are the remnants of Pleistocene-era pluvial lakes, although it may have occurred in the area for much longer. Here we use mitochondrial DNA sequence data to assess range-wide genetic diversity of R. solitarius, and to estimate divergence times to determine whether pluvial drainages played an important role in shaping intraspecific genetic diversity. Genetic diversification within R. solitarius began during the early to mid-Pleistocene, separating populations within two sets of valleys (Butte/Ruby and Goshute/Steptoe). Additional diversification in each of the two sets of valleys occurred more recently, in the mid- to late-Pleistocene. Holocene desiccation has further isolated populations, and each population sampled contains unique mtDNA haplotypes. Pluvial drainage patterns did contribute to the genetic structure observed within R. solitarius, but most of the intraspecific diversification does not appear to be associated with the Last Glacial Maximum. Holocene desiccation has also contributed to the observed genetic structure. The relict dace populations we sampled are all unique, and we recommend that future management efforts should strive to preserve as much of the genetic diversity as possible.