Lack of assortative mating might explain reduced phenotypic differentiation where two grasshopper species meet

Hybridization is an evolutionary process with wide-ranging potential outcomes, from providing populations with important genetic variation for adaptation to being a substantial fitness cost leading to extinction. Here, we focussed on putative hybridization between two morphologically distinct species of New Zealand grasshopper. We collected Phaulacridium marginale and Phaulacridium otagoense specimens from a region where mitochondrial introgression had been detected and where their habitat had been modified by introduced mammals eating the natural vegetation and by the colonization of many non-native plant species. In contrast to observations in the 1970s, our sampling of wild pairs of grasshoppers in copula provided no evidence of assortative mating with respect to species. Geometric morphometrics on the pronotum shape of individuals from areas of sympatry detected phenotypically intermediate specimens (putative hybrids), and the distribution of phenotypes in most areas of sympatry was..., , , # Lack of assortative mating might explain reduced phenotypic differentiation where two grasshopper species meet

Authors: Mary Morgan-Richards, Maurine Vilcot, Steven A. Trewick

The data are mitochondrial DNA sequences and morphometric values relating to variance among Phaulacridium (Insect, Orthoptera, Acrididae) grasshoppers that were sampled in Aotearoa (New Zealand).

The morphometric data are 'traditional' metrics of eight nonindependent variables comprising three size differences (hind femur length, hind tibia length, and tegmina length), three ratios and two angles of the pronotum margin in dorsal view; and geometric coordinates derived from twelve geometric landmarks were identified and digitized around the perimeter of the dorsal surface of the pronotum.

DNA sequences result from Sanger sequencing of PCR products from 95 individual grasshoppers. With previous data, this provides an alignment of nucleotide data for 243 individuals.

## Description of the data folder:

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