Genetic relatedness of the Preble's meadow jumping mouse (Zapus hudsonius preblei) to nearby subspecies of Z. hudsonius as inferred from variation in cranial morphology, mitochondrial DNA and microsatellite DNA: implications for taxonomy and conservation

Abstract

The Preble's meadow jumping mouse (Zapus hudsonius preblei) is listed as a threatened subspecies under the United States Endangered Species Act (US‐ESA). The quantitative description of this subspecies was based on cranial measurements of only three adult specimens. It is one of twelve subspecies of Z. hudsonius and is a peripheral population at the western edge of its range. We tested the uniqueness of Z. h. preblei relative to other nearby subspecies of Z. hudsonius using a hypothesis testing approach and analyses of cranial morphometric, mtDNA sequence and nuclear microsatellite data obtained from museum specimens and archived tissues. Morphometric analysis of variance did not support the original description of Z. h. preblei as a subspecies. Principal component analysis of these data showed Z. h. preblei within the range of variation found in Z. h. campestris and Z. h. intermedius. Discriminant analysis correctly classified only 42% of Z. h. preblei skulls at jackknifed posterior probabilities >0.95 relative to Z. h. campestris. All mtDNA haplotypes found in Z. h. preblei were also found in Z. h. campestris. Simulation based estimates of current and historical gene flow (MDIV) revealed low, but non‐zero, mtDNA gene flow among Z. h. preblei and several nearby subspecies. Analyses of five nuclear microsatellite loci using population pairwise FST, BAPS and STRUCTURE were consistent with morphometric and mtDNA results. These revealed low levels of genetic structure and evidence of recent gene flow and bottlenecks in Z. h. preblei. Due to a lack of clearly recognisable genetic, morphological, or adaptive differences, we synonymise Z. h. preblei and Z. h. intermedius with Z. h. campestris. We suggest that candidates for listing under the US‐ESA, or similar biodiversity laws, be evaluated for genetic and/or morphological uniqueness to prevent the misallocation of resources to non‐distinct taxa like Z. h. preblei.

The politics in environmental science: The Endangered Species Act and the Preble's mouse controversy

“…In December 2003, Rob Ramey, a biologist who at the time was employed by the Denver Museum of Nature and Science, published a report in which he was lead author (see Ramey et al 2005). This article disputed the claim that the mouse is a distinct subspecies.…”

The Preble's meadow jumping mouse: subjective subspecies, advocacy and management

“…I read with concern the letters to the editor regarding the Preble's meadow jumping mouse Zapus hudsonius preblei in which Martin (2006) criticized Ramey et al (2005) for questioning the subspecies designation and the editor for a failed peer review, and Crandall (2006) defended his editorship.…”

“…The subspecies status of this mouse has been discussed extensively (Ramey et al, 2005(Ramey et al, , 2006Crandall, 2006;Martin, 2006;Vignieri et al, 2006) because it has been listed as threatened under the Endangered Species Act (ESA). Briefly, the Preble's mouse was designated a subspecies with limited descriptive morphological data.…”

“…Ramey et al (2005) used a hypothesistesting approach for genetic, ecological and morphological data and concluded that the subspecies designation was not warranted. Vignieri et al (2006) presented criteria (no or significantly reduced gene flow), acknowledged subspecies are not well defined, and then concluded the Preble's mouse is a legitimate subspecies.…”

“…However, discussion of the Preble's mouse subspecies status has degenerated to accusations of 'advocacy dressed up as science' (Martin, 2006). Crandall (2006) pointed out that Martin himself was practicing advocacy while accusing Ramey et al (2005) of practicing advocacy. It is important to note the applicable definition of advocacy: defending or maintaining a cause or proposal (Webster's Ninth New Collegiate Dictionary).…”