Submitted to: Journal of Orthoptera Research
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/8/2004
Publication Date: 12/1/2004
Citation: Vandyke, K.A., Lockwood, J.A., Kazmer, D.J. 2004. Association of genetic lineages with ecological features in a polyphagous montane grasshopper species . Journal of Orthoptera Research. 13(2):205-209. Interpretive Summary: Understanding how species adapt to variable and changing environments is of fundamental importance to managing biological diversity and ecosystem services. In this study, we looked at how 3 genetic lineages within one species of a montane grasshopper are distributed across a broad array of environmental and geographical features. Soil texture, but no other environmental or geographical factor, was found to be the basis of ecological differentiation among the 3 lineages. This grasshopper spends the vast majority of its lifetime in the soil and survival of the soil-dwelling egg stage is most likely dependent on the positioning of the egg pod in the soil profile, with soil texture influencing the optimal positioning of the egg pod. Retaining the intraspecific diversity represented by these 3 genetic lineages may simply be a matter of conserving alpine meadows with different soil textures.
Technical Abstract: Understanding the relationships between intraspecific diversity and habitat has been greatly enhanced with the advent of molecular markers. Such understanding may help to elucidate complex microevolutionary processes. Melanoplus alpinus, a montane/alpine grasshopper species found in the central and northern Rocky Mountains, has a disjunct distribution with highly divergent mtDNA lineages, structured among meadows and drainages within mountain ranges. Previous analyses showed that genetic differentiation is not distance driven, so habitat factors may account for genetic structuring and diversity within the species. In this study, 3 mtDNA lineages were analyzed for their association with ecological variables, and PCR-RFLP haplotype genetic diversities were analyzed for relationships with elevation, elevation-latitude index, and meadow size. Chi-square analysis revealed mtDNA lineage predominance in particular soil textures, indicating the potential of soil to function as a limiting environmental factor in the distribution of lineages within this species. Genotype-habitat associations did not extend beyond soil, however. No significant relationships existed between genetic diversity within meadows and elevation, elevation-latitude index, or meadow size.