Meeting Abstract
P1.85 Friday, Jan. 4 Parthenogenetic whiptail lizards vary more between year classes than by size, age or habitat TULGA, S*; FERRER, E; WERNING, S; Univ. of California, Berkeley; Univ. of California, Berkeley; Univ. of California, Berkeley sarahtulga@berkeley.edu
Genetic, ontogenetic, environmental, and sexual differences all contribute to observed morphological variation within species, but teasing apart the genetic contribution is difficult even when controlling for sex, age, and habitat. This limits our ability to determine what “baseline” levels of variation we should expect in the absence of these factors. Parthenogenetic species provide ideal tests of whether reduced genetic variation results in lower morphological variation. We analyzed 27 skulls of Aspidoscelis velox, a parthenogenetic whiptail lizard, using geometric morphometrics. To reduce the effects of factors resulting from habitat difference, these were primarily collected in 2010 and 2011 from a 500 square meter area. We photographed each skull in dorsal, lateral, and ventral views, and statistically quantified variation across 67 landmarked points using Procrustes superimposition. We analyzed the data using tpsRelw, MorphoJ, and Coorgen. We grouped specimens based on year collected, field-assessed age, and size based on skull length. Dorsal landmarks varied with collection year and size, whereas the ventral and lateral data showed shape trends in all three groups. Year collected was the strongest influence in all orientations, with a large shape difference between the two years. This large split is visible in all CVA, PCA and regression plots, and the general variation shown by these groupings is greater than expected. This suggests that epigenetic factors contribute greatly to individual morphological variation even when age, sexual, genetic, and habitat variations are low. Continuing research includes a comparative assessment of variation in gonochoristic whiptail species and further investigation into climate or environmental changes between the years collected.
