Exceptional Changes in Skeletal Anatomy under Domestication: The Case of Brachycephaly

Geiger, Madeleine; Schoenebeck, Jeffrey J.; Schneider, Richard A.; Schmidt, Martin J.; Fischer, Martin S.; Sánchez‐Villagra, Marcelo R.

doi:10.1093/iob/obab023

Cited by 19 publications

(25 citation statements)

References 224 publications

(314 reference statements)

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“…Although these scaling relationships lead to relatively short faces in small domestic rabbits (and thus to a pattern which might be described as “allometric” brachycephaly; Geiger et al, 2021 ), this appears to be purely the result of negatively allometric scaling of the braincase. Thus, although the here reported scaling relationship of braincase size among domestic rabbits is in accordance with the “rule of Haller” (e.g., Bauchot, 1978 ; Bronson, 1979 ; Emerson & Bramble, 1993 ; Gould, 1975 ; Klatt, 1913 ; Lüps, 2008 ; Radinsky, 1985 ), the scaling relationship of the face does not corroborate with the “cranial evolutionary allometry hypothesis” (CREA), which suggest that larger forms of the same species or larger species within a clade have relatively long faces (positive allometry; e.g., Cardini & Polly, 2013 ), and which has been substantiated in a number of different taxa (Bright et al, 2016 ; Cardini, 2019 ; Cardini & Polly, 2013 ; Cardini et al, 2015 ; Emerson & Bramble, 1993 ; Le Verger et al, 2020 ; Radinsky, 1985 ; Tamagnini et al, 2017 ).…”

Section: Discussionmentioning

confidence: 99%

Cranial shape variation in domestication: A pilot study on the case of rabbits

2022

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Domestication leads to phenotypic characteristics that have been described to be similar across species. However, this “domestication syndrome” has been subject to debate, related to a lack of evidence for certain characteristics in many species. Here we review diverse literature and provide new data on cranial shape changes due to domestication in the European rabbit (Oryctolagus cuniculus) as a preliminary case study, thus contributing novel evidence to the debate. We quantified cranial shape of 30 wild and domestic rabbits using micro‐computed tomography scans and three‐dimensional geometric morphometrics. The goal was to test (1) if the domesticates exhibit shorter and broader snouts, smaller teeth, and smaller braincases than their wild counterparts; (2) to what extent allometric scaling is responsible for cranial shape variation; (3) if there is evidence for more variation in the neural crest‐derived parts of the cranium compared with those derived of the mesoderm, in accordance with the “neural crest hypothesis.” Our own data are consistent with older literature records, suggesting that although there is evidence for some cranial characteristics of the “domestication syndrome” in rabbits, facial length is not reduced. In accordance with the “neural crest hypothesis,” we found more shape variation in neural crest versus mesoderm‐derived parts of the cranium. Within the domestic group, allometric scaling relationships of the snout, the braincase, and the teeth shed new light on ubiquitous patterns among related taxa. This study—albeit preliminary due to the limited sample size—adds to the growing evidence concerning nonuniform patterns associated with domestication.

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Section: Discussionmentioning

confidence: 99%

Cranial shape variation in domestication: A pilot study on the case of rabbits

2022

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“…Это дополнительно объясняет развитие у данных пород укорочения не только головы, но и конечностей (вероятно в связи с преждевременным эндохондральным окостенением зон роста на апикальных концах трубчатых костей). Таким образом, разумной гипотезой является нарушение эндохондральной оссификации, то есть хондродисплазия или хондродистрофия, как механизм развития брахицефалии [7]. Возможно эти данные связаны с наличием мутации Drawt.…”

Section: результаты и обсуждениеunclassified

“…В настоящее время существует множество предполагаемых этиологических факторов дентальной болезни [14]. Среди которых выделяют врожденные аномалии челюсти: прогению [2], прогнатию [7], пороки развития зубов. Приобретенные причины могут включать травмы, неправильное питание, метаболические заболевания костей, новообразования или совокупность всех вышеперечисленных причин [14].…”

Section: Introductionunclassified

“…Способствует этому и тот факт, что у карликовых пород относительно размеров их тела зубы крупнее, нежели у крупных пород. Следовательно, это приводит к тому, что полный набор зубов может не помещаться в уко-роченной челюсти [7,9]. N.D. Harvey с коллегами на основании статистических данных и эксперимента было указано, что люди предпочитают в качестве домашних питомцев кроликов с более плоской мордой.…”

Section: Introductionunclassified

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Frequency of dental disease and associated pathologies in dwarf rabbits

Koroleva

Titova

2022

jour

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Dental disease is common in domestic rabbits. It manifests itself in a variety of clinical signs and can contribute to the development of rhinosinusitis and dacryocystitis. By itself, dental disease prevents the animal from eating normally, which contributes to the development of diseases of the gastrointestinal tract, exhaustion and death of animals. Over the past few centuries, rabbits have become widespread as pets, which has rather led to an increase in the popularity of dwarf rabbits. At the same time, in addition to the small size of the body, some brachycephaly of the head is observed in dwarf rabbits: shortening of the facial skull relative to the size of the body and brain skull. A number of authors argue that such morphological changes lead to an increased risk of developing dental disease and associated pathologies (dacryocystitis and rhinosinusitis).

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“…This study design sought to maximise diversity of domestic forms and provide comparisons across different forms while avoiding intensive artificial selection regimes that have yielded exceptional morphological changes, e.g., brachephalic skull conformations seen in breeds such as pugs (Geiger et al, 2021). Nevertheless, there are several challenges associated with study design for sampling domestic and wild populations from historical collections.…”

Section: Limitationsmentioning

confidence: 99%

Developmental instability in domesticated mammals

Wilson

2021

J Exp Zool Pt B

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Measures of fluctuating asymmetry (FA) have been adopted widely as an estimate of developmental instability. Arising from various sources of stress, developmental instability is associated with an organism's capacity to maintain fitness. The process of domestication has been framed as an environmental stress with human‐specified parameters, suggesting that FA may manifest to a larger degree among domesticates compared to their wild relatives. This study used three‐dimensional geometric morphometric landmark data to (a) quantify the amount of FA in the cranium of six domestic mammal species and their wild relatives and, (b) provide novel assessment of the commonalities and differences across domestic/wild pairs concerning the extent to which random variation arising from the developmental system assimilates into within‐population variation. The majority of domestic mammals showed greater disparity for asymmetric shape, however, only two forms (Pig, Dog) showed significantly higher disparity as well as a higher degree of asymmetry compared to their wild counterparts (Wild Boar, Wolf). Contra to predictions, most domestic and wild forms did not show a statistically significant correspondence between symmetric shape variation and FA, however, a moderate correlation value was recorded for most pairs (r‐partial least squares >0.5). Within pairs, domestic and wild forms showed similar correlation magnitudes for the relationship between the asymmetric and symmetric components. In domesticates, new variation may therefore retain a general, conserved pattern in the gross structuring of the cranium, whilst also being a source for response to selection on specific features.

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Exceptional Changes in Skeletal Anatomy under Domestication: The Case of Brachycephaly

Cited by 19 publications

References 224 publications

Cranial shape variation in domestication: A pilot study on the case of rabbits

Cranial shape variation in domestication: A pilot study on the case of rabbits

Frequency of dental disease and associated pathologies in dwarf rabbits

Developmental instability in domesticated mammals

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