@article{44bdb423787d4b9ea8b839d61fb85f39,
title = "Intraspecific variation in semicircular canal morphology—A missing element in adaptive scenarios?",
abstract = "Objectives: Recent evidence suggests that the amount of intraspecific variation in semicircular canal morphology may, itself, be evidence for varying levels of selection related to locomotor demands. To determine the extent of this phenomenon across taxa, we expand upon previous work by examining intraspecific variation in canal radii and canal orthogonality in a broad sample of strepsirrhine and platyrrhine primates. Patterns of interspecific variation are re-examined in light of intraspecific variation to better understand the resolution at which locomotion can be reconstructed from single individuals. Materials and Methods: Data was collected from high-resolution CT scans of 14 size-matched, related species. Six of these taxa have existing data on rotational head speeds. Results: The level of intraspecific variation was found to differ in strepsirrhine and in platyrrhine species pairs, with larger ranges of variation generally observed for the slower moving taxon than the faster moving one. Taxa that are classified as relatively agile can to some extent be separated from those who are slower-moving, but only when comparing similarly sized, closely related species with more extreme forms of locomotion. Discussion: Our findings agree with previous research showing that canal intraspecific variation can fluctuate according to species-specific locomotor behavior and extends this further by identifying behaviors that may be under unusual selective pressure. It also demonstrates the complexity of interpreting inner ear morphology in the context of broadly applicable locomotor “categories” of the kind commonly used in behavioral studies. We suspect that simplified models predicting vestibular sensitivity may be unable to differentiate behaviors when only a single specimen is available.",
keywords = "inner ear variation, primates, selective constraints, vestibular labyrinth",
author = "Gonzales, {Lauren A.} and Malinzak, {Michael D.} and Kay, {Richard F.}",
note = "Funding Information: information The Leakey Foundation; National Science Foundation, Grant/Award Number: BCS-1552848, BCS 1440742 This study was funded by the LSB Leakey Foundation and in part by the National Science Foundation. We thank Christine Wall, Blythe Williams, Louis Roth and Michael Granatosky for statistical advice and constructive comments to the manuscript. We also thank Jimmy Thostenson, Doug Boyer, Christine Fantauzzi, and Crystal Terry for their generous help with computed tomography scanning of specimens and for technical help and advice. Darbi Griffith for her time spent uploading CT scans to the Gonzales Skull Project in Morphosource. We thank Tum Hullar M.D. for giving us access to the MATLAB code. Many thanks to Eileen Westwig, Darren Lunde, and Esther Langan for access to osteological specimens from the American Museum of Natural History and the Smithsonian Institution (Natural History). We also give a special thanks to Lynn Copes, Liz St. Clair, Eva Garrett, and Kari Allen who gave permission to use CT scans of their specimens for this study. Finally, we are very grateful to Mary Silcox and Eric Ekdale for their comments during the review process. L.G. and R.K. initiated and designed the project, L.G. scanned specimens, collected data, and analyzed results, L.G., R.K., and M.M. discussed results and wrote the manuscript. Funding Information: This study was funded by the LSB Leakey Foundation and in part by the National Science Foundation. We thank Christine Wall, Blythe Williams, Louis Roth and Michael Granatosky for statistical advice and constructive comments to the manuscript. We also thank Jimmy Thostenson, Doug Boyer, Christine Fantauzzi, and Crystal Terry for their generous help with computed tomography scanning of specimens and for technical help and advice. Darbi Griffith for her time spent uploading CT scans to the Gonzales Skull Project in Morpho-source. We thank Tum Hullar M.D. for giving us access to the MATLAB code. Many thanks to Eileen Westwig, Darren Lunde, and Esther Langan for access to osteological specimens from the American Museum of Natural History and the Smithsonian Institution (Natural History). We also give a special thanks to Lynn Copes, Liz St. Clair, Eva Garrett, and Kari Allen who gave permission to use CT scans of their specimens for this study. Finally, we are very grateful to Mary Silcox and Eric Ekdale for their comments during the review process. Publisher Copyright: {\textcopyright} 2018 Wiley Periodicals, Inc.",
year = "2018",
month = jan,
doi = "10.1002/ajpa.23692",
language = "English",
volume = "168",
pages = "10--24",
journal = "American Journal of Physical Anthropology",
issn = "0002-9483",
publisher = "Wiley-Liss Inc.",
number = "1",
}