Phenotype and animal domestication : A study of dental variation between domestic, wild, captive, hybrid and insular Sus scrofa

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements We thank the institutions and individuals that provided access to collections, especially the curators of the Museum für Naturkunde, Berlin; Zoologische Staatssammlung, München; Muséum National d’Histoire Naturelle, Paris; Muséum d’Histoire Naturelle, Genève; National Museum of Natural History, Washington; The Field Museum, Chicago and The American Museum of Natural History, New-York. We also thank Jean-Denis Vigne, Nelly Gidaszewski, Vincent Debat and Mathieu Joron for fruitful discussions. This work was supported by a research grant from the Natural Environment Research Council, UK (grant number NE/F003382/1).Peer reviewedPublisher PD

Investigating the impact of captivity and domestication on limb bone cortical morphology: an experimental approach using a wild boar model

The lack of bone morphological markers associated with the human control of wild animals has prevented the documentation of incipient animal domestication in archaeology. Here, we assess whether direct environmental changes (i.e. mobility reduction) could immediately affect ontogenetic changes in long bone structure, providing a skeletal marker of early domestication. We relied on a wild boar experimental model, analysing 24 wild-born specimens raised in captivity from 6 months to 2 years old. The shaft cortical thickness of their humerus was measured using a 3D morphometric mapping approach and compared with 23 free-ranging wild boars and 22 pigs from different breeds, taking into account sex, mass and muscle force differences. In wild boars we found that captivity induced an increase in cortical bone volume and muscle force, and a topographic change of cortical thickness associated with muscular expression along a phenotypic trajectory that differed from the divergence induced by selective breeding. These results provide an experimental proof of concept that changes in locomotor behaviour and selective breeding might be inferred from long bones morphology in the fossil and archaeological record. These trends need to be explored in the archaeological record and further studies are required to explore the developmental changes behind these plastic responses

The mark of captivity: plastic responses in the ankle bone of a wild ungulate (Sus scrofa)

International audienceDeciphering the plastic (non-heritable) changes induced by human control over wild animals in the archaeological record is challenging. We hypothesized that changes in locomotor behaviour in a wild ungulate due to mobility control could be quantified in the bone anatomy. To test this, we experimented with the effect of mobility reduction on the skeleton of wild boar (Sus scrofa), using the calcaneus shape as a possible © 2020 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. phenotypic marker. We first assessed differences in shape variation and covariation in captive-reared and wild-caught wild boars, taking into account differences in sex, body mass, available space for movement and muscle force. This plastic signal was then contrasted with the phenotypic changes induced by selective breeding in domestic pigs. We found that mobility reduction induces a plastic response beyond the shape variation of wild boars in their natural habitat, associated with a reduction in the range of locomotor behaviours and muscle loads. This plastic signal of captivity in the calcaneus shape differs from the main changes induced by selective breeding for larger muscle and earlier development that impacted the pigs' calcaneus shape in a much greater extent than the mobility reduction during the domestication process of their wild ancestors

Morphology and Variation of the Asiatic Wild Ass (\u3ci\u3eEquus hemionus hemionus\u3c/i\u3e)

A collection of recent skeletal remains from the Asiatic wild ass (Equus hemionus hemionus PALLAS) was prepared and stored in the Museum of Domesticated Animals “JULIUS KÜHN” in Halle, Germany. The collection is based on carcass remains sampled between 2001 and 2006 under the leadership of Michael Stubbe during joint Mongolian-German Biological Expeditions Skeletal remains of 43 individual specimens were studied (18 mares, 15 stallions, and 10 juvenile asses). The determination of sex and age was initially based on carcass information from observations made in situ in the field. Subsequently, skull traits, including dentition and development of canine teeth were included to determine the ages of individuals. All animals were classified by age using histomorphological sections and observations of the tooth structure. During this study, Individual ages ranged from a foal under one year to an 18-year old stallion. The osteometric measurements of the fully grown long bones (humerus, radius, femur, tibia, and metacarpalia) were performed according to A. von den Driesch, 1976. The quantitative analysis of size and shape of long bones allows a description of the morphology of the species. Commonly, this method is used for archaeozoological remains. Here the same method is applied to the largest preserved set of skeletons of the recent population of wild asses from the southern Mongolian Gobi. As expected, morphometric traits studied show no differences between left and right hand side and comparisons of standard morphometric traits predominantly show no sexual dimorphism with one exception: A highly significant difference is found in the length of the humerus between sexes. It may be hypothesized that this sexual dimorphism is linked to an elaborate anti-predator defense strategy against wolves. Apparently differences in the length of the humerus cause a small shift in the proportion of the forehand

Taxonomic and phylogenetic signals in bovini cheek teeth: Towards new biosystematic markers to explore the history of wild and domestic cattle

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Morphological Approach to Genetic Variability of the Asiatic Wild Ass ( Equus hemionus ) Using Non-metric Skull Characters

The Asiatic wild ass ( Equus hemionus ) is a globally endangered large mammal threatened by competition with livestock, poaching as well as habitat fragmentation and loss. Because of these environmental stresses it can be assumed that the species suff ers from lower developmental stability and that barrier eff ects could cause genetic isolation. To gain more insight into the population genetics of the Asiatic wild ass, a series of 440 skulls found in two Gobi regions of Mongolia were examined. The epigenetic variability and epigenetic distance between the samples as well as their fl uctuating asymmetry were studied by using 62 non-metric skull characters to test and evaluate possible genetic depletion, genetic isolation and the general infl uences during ontogenesis. The high epigenetic variability, I ev = 0.39 did not diff er between the two regions indicating no evidence of genetic depression. The very low, but signifi cant epigenetic divergence of MMD = 0.05 between the Dzungarian Gobi and the Southern Gobi suggests restricted connectivity. The moderate degree of fl uctuating asymmetry (FA = 0.11 – 0.15) found gives no signs of reduced developmental stability. Thus, our results suggest that Asiatic wild ass from Mongolia are from genetically viable populations

Constraints associated with captivity alter craniomandibular integration in wild boar

International audienceThe domestication process is associated with substantial phenotypic changes through time. However, although morphological integration between biological structures is purported to have a major influence on the evolution of new morphologies, little attention has been paid to the influence of domestication on the magnitude of integration. Here, we assessed the influence of constraints associated with captivity, considered as one of the crucial first steps in the domestication process, on the integration of cranial and mandibular structures. We investigated the craniomandibular integration in Western European Sus scrofa using three‐dimensional (3D) landmark‐based geometric morphometrics. Our results suggest that captivity is associated with a lower level of integration between the cranium and the mandible. Plastic responses to captivity can thus affect the magnitude of integration of key functional structures. These findings underline the critical need to develop integration studies in the context of animal domestication to better understand the processes accountable for the set‐up of domestic phenotypes through time

Sorting the flock: Quantitative identification of sheep and goat from isolated third lower molars and mandibles through geometric morphometrics

International audienceSheep and goat are often herded together and show morphological similarities in their skeleton. Being able to identify archaeological remains of these two taxa to species level is particularly important for understanding and characterising past herding practices. Discrete criteria are now available to identify a large number of their bones and teeth, and quantitative approaches have been developed for post-cranial elements but not for mandible and isolated teeth. In this paper we explore the discriminating potential of geometric morphometrics to identify modern sheep and goat third lower molar and mandible and its application on archaeological specimens. The size and shape of the mandible and the third lower molar of 143 modern specimens (101 sheep and 42 goats) were quantified using 2D-landmark and sliding semi-landmarks geometric morphometric approaches. The results show that sheep and goat differ in terms of the size, shape, and form (i.e. size and shape together) in both studied elements. Classification accuracy of the two species reaches 93.3% (CI: 90.0–95.7%) for third lower molar shape, 62.7% (CI 57.1–68.6%) for third lower molar size, 95.2% (CI: 92.0–97.4%) for mandible shape and 84.0% (CI 81.6–86.8%) for mandible size. Form does not provide better classification than shape alone. Sex and age appear to have little impact on the ability to differentiate between sheep and goat, despite the two species displaying distinct sexual dimorphism and changes through age. The same methodology was then applied on 32 Middle Ages third lower molars from Missignac-Saint Gilles le Vieux, Aimargues, France. The identifications obtained through geometric morphometrics were only partially congruent with the identifications based on visual observations calling for caution in the interpretation and further investigations. Further research should include molecular identification of the archaeological specimens to assess whether the geometric morphometric identification can be made with confidence for all periods and all geographic areas. Nevertheless, the results obtained with the newly developed geometric morphometric protocols represent an important contribution toward a better understanding of past livestock husbandry practice

ZooMS confirms geometric morphometrics species identification of ancient sheep and goat

Geometric morphometrics can effectively distinguish isolated third lower molars of present-day sheep and goat, but its applicability to archaeological specimens has yet to be established. Using a modern reference collection of 743 sheep and goats and a two-dimensional landmark-based geometric morphometric (GMM) protocol, this study aimed to morphometrically identify 109 archaeological specimens, used as case studies, dating from the Late Neolithic to the modern period/era. These morphometric identifications were then compared to molecular identifications via collagen peptide mass fingerprinting, known as Zooarcheology by Mass Spectrometry (ZooMS). ZooMS confirmed the morphometric identifications for 104 specimens, with the five misidentified specimens all morphometrically identified as goat. Modern sheep and goats have larger teeth and distinct shapes compared to their archaeological counterparts, suggesting strong differences between archaeological and modern specimens potentially linked with recent breed improvement or geographical origin of the specimens. In addition, for both species, some of the archaeological dental morphologies do not match with any of our modern references. This study validates the applicability of geometric morphometrics for identifying isolated archaeological sheep and goat teeth. It represents a stepping stone for future, non-destructive, bioarchaeological studies of the two species