chrismay

• Tsuboi, Masahito; Kopperud, Bjørn Tore; Matschiner, Michael; Grabowski, Mark Walter; Syrowatka, Christine & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2024). Antler Allometry, the Irish Elk and Gould Revisited. Evolutionary Biology. ISSN 0071-3260. 51, s. 149–165. doi: 10.1007/s11692-023-09624-1. Fulltekst i vitenarkiv Vis sammendrag

  The huge antlers of the extinct Irish elk have invited evolutionary speculation since Darwin. In the 1970s, Stephen Jay Gould presented the first extensive data on antler size in the Irish elk and combined these with comparative data from other deer to test the hypothesis that the gigantic antlers were the outcome of a positive allometry that constrained large-bodied deer to have proportionally even larger antlers. He concluded that the Irish elk had antlers as predicted for its size and interpreted this within his emerging framework of developmental constraints as an explanatory factor in evolution. Here we reanalyze antler allometry based on new morphometric data for 57 taxa of the family Cervidae. We also present a new phylogeny for the Cervidae, which we use for comparative analyses. In contrast to Gould, we find that the antlers of Irish elk were larger than predicted from the allometry within the true deer, Cervini, as analyzed by Gould, but follow the allometry across Cervidae as a whole. After dissecting the discrepancy, we reject the allometric-constraint hypothesis because, contrary to Gould, we find no similarity between static and evolutionary allometries, and because we document extensive non-allometric evolution of antler size across the Cervidae.

• Tsuboi, Masahito; Kopperud, Bjørn Tore; Syrowatka, Christine; Grabowski, Mark Walter; Voje, Kjetil L. & Pelabon, Christophe [Vis alle 7 forfattere av denne artikkelen] (2020). Measuring Complex Morphological Traits with 3D Photogrammetry: A Case Study with Deer Antlers. Evolutionary Biology. ISSN 0071-3260. 47, s. 175–186. doi: 10.1007/s11692-020-09496-9. Fulltekst i vitenarkiv Vis sammendrag

  The increasing availability of 3D-imaging technology provides new opportunities for measuring morphology. Photogrammetry enables easy 3D-data acquisition compared to conventional methods and here we assess its accuracy for measuring the size of deer antlers, a complex morphological structure. Using a proprietary photogrammetry software, we generated 3D images of antlers for 92 individuals from 29 species of cervids that vary widely in antler size and shape and used these to measure antler volume. By repeating the process, we found that the relative error averaged 8.5% of object size. Errors in converting arbitrary voxel units into real volumetric units accounted for 70% of the measurement variance and can therefore be reduced by replicating the conversion. We applied the method to clay models of known volume and found no indication of bias. The estimation was robust against variation in imaging device, distance and operator, but approximately 40 images per specimen were necessary to achieve good precision. We used the method to show that conventional measures of main-beam length are relatively poor estimators of antler volume. Using loose antlers of known weight, we also showed that the volume may be a relatively poor predictor of antler weight due to variation in bone density across species. We conclude that photogrammetry can be an efficient and accurate tool for measuring antlers, and likely many other complex morphological traits.

• Mayer, Christine; Windhager, Sonja; Schaefer, Katrin & Mitteroecker, Philipp (2017). BMI and WHR Are Reflected in Female Facial Shape and Texture: A Geometric Morphometric Image Analysis. PLOS ONE. 12(1). doi: 10.1371/journal.pone.0169336. Fulltekst i vitenarkiv Vis sammendrag

  Facial markers of body composition are frequently studied in evolutionary psychology and are important in computational and forensic face recognition. We assessed the association of body mass index (BMI) and waist-to-hip ratio (WHR) with facial shape and texture (color pattern) in a sample of young Middle European women by a combination of geometric morphometrics and image analysis. Faces of women with high BMI had a wider and rounder facial outline relative to the size of the eyes and lips, and relatively lower eyebrows. Furthermore, women with high BMI had a brighter and more reddish skin color than women with lower BMI. The same facial features were associated with WHR, even though BMI and WHR were only moderately correlated. Yet BMI was better predictable than WHR from facial attributes. After leave-one-out cross-validation, we were able to predict 25% of variation in BMI and 10% of variation in WHR by facial shape. Facial texture predicted only about 3–10% of variation in BMI and WHR. This indicates that facial shape primarily reflects total fat proportion, rather than the distribution of fat within the body. The association of reddish facial texture in high-BMI women may be mediated by increased blood pressure and superficial blood flow as well as diet. Our study elucidates how geometric morphometric image analysis serves to quantify the effect of biological factors such as BMI and WHR to facial shape and color, which in turn contributes to social perception.

• Mayer, Christine & Hansen, Thomas F (2017). Evolvability and Robustness: A paradox restored. Journal of Theoretical Biology. ISSN 0022-5193. 430, s. 78–85. doi: 10.1016/j.jtbi.2017.07.004. Fulltekst i vitenarkiv
• Heuberer, Simone; Dvorak, Gabriele; Mayer, Christine; Watzek, G & Zechner, W (2014). Dental implants are a viable alternative for compensating oligodontia in adolescents. Clinical Oral Implants Research. ISSN 0905-7161. 26(4), s. e22–e27. doi: 10.1111/clr.12323. Fulltekst i vitenarkiv
• Herdina, Anna N; Hulva, Pavel; Horáček, Ivan; Benda, Petr; Mayer, Christine & Hilgers, Helge [Vis alle 7 forfattere av denne artikkelen] (2014). MicroCT Imaging Reveals Morphometric Baculum Differences for Discriminating the Cryptic Species Pipistrellus pipistrellus and P. pygmaeus. Acta Chiropterologica. ISSN 1508-1109. 16(1), s. 157–168. doi: 10.3161/150811014X683372. Fulltekst i vitenarkiv
• Mayer, Christine; Metscher, Brian; Mueller, Gerd B. & Mitteroecker, Philipp (2014). Studying Developmental Variation with Geometric Morphometric Image Analysis (GMIA). PLOS ONE. 9(12). doi: 10.1371/journal.pone.0115076. Fulltekst i vitenarkiv

Se alle arbeider i NVA

• Mayer, Christine & Hansen, Thomas F (2017). Evovability and Robustness in Models of Pattern Formation. Fulltekst i vitenarkiv
• Mayer, Christine (2017). Evolvability and robustness in models of pattern formation. Fulltekst i vitenarkiv
• Mayer, Christine & Hansen, Thomas F (2016). Resolving the relationship between evolvability and robustness using Boolean Genotype-Phenotype Maps. Fulltekst i vitenarkiv
• Mayer, Christine (2016). Resolving the relationship between evolvability and robustness using Boolean Genotype-Phenotype Maps. Fulltekst i vitenarkiv
• Mayer, Christine (2015). Genotype-Phenotype Maps: Exploring evolvability and robustness by using a multilinear framework combined with the idea of Boolean networks. Fulltekst i vitenarkiv
• Mayer, Christine & Hansen, Thomas F (2015). Genotype-Phenotype maps: Exploring evolvability and robustness by combining a multilinear framework with Boolean networks. Fulltekst i vitenarkiv
• Mayer, Christine & Hansen, Thomas F (2015). Modeling Genotype-Phenotype Maps by combining a multilinear model with Boolean Networks. Fulltekst i vitenarkiv
• Mayer, Christine; Metscher, Brian; Mueller, Gerd B. & Mitteroecker, Phillipp (2014). Quantification of developmental variation in rainbow trout using geometric morphometric image analysis. Fulltekst i vitenarkiv

Se alle arbeider i NVA