Phenotypic Plasticity in Vertebrate Dentitions

Abstract

Synopsis Vertebrates interact directly with food items through their dentition, and these interactions with trophic resources could often feedback to influence tooth structure. Although dentitions are often considered to be a fixed phenotype, there is the potential for environmentally induced phenotypic plasticity in teeth to extensively influence their diversity. Here, we review the literature concerning phenotypic plasticity of vertebrate teeth. Even though only a few taxonomically disparate studies have focused on phenotypic plasticity in teeth, there are a number of ways teeth can change their size, shape, or patterns of replacement as a response to the environment. Elucidating the underlying physiological, developmental, and genetic mechanisms that generate phenotypic plasticity can clarify its potential role in the evolution of dental phenotypes.

Convergent Evolution of Cichlid Fish Pharyngeal Jaw Dentitions in Mollusk-Crushing Predators: Comparative X-Ray Computed Tomography of Tooth Sizes, Numbers, and Replacement

“…Replacement teeth were never smaller in any species suggesting that, for instance, molariform H. minckleyi is not likely to switch to being papilliform H. minckleyi. As the cichlid pharyngeal jaw and its associated teeth have often been suggested to exhibit adaptive phenotypic plasticity (Huysseune 1995;Muschick et al 2011;Gunter and Meyer 2014;Schneider et al 2014;Gunter et al 2017;Schneider and Meyer 2017;Karagic et al 2020a), our analyses likely also provides general parameters for how teeth can be replaced in these fishes and therefore how their pharyngeal jaw phenotypes can respond plastically to more durable prey. However, our inferences are limited to a single cyde of tooth replacement which could last for as little as 50 days in some of these fishes (Fraser et al 2013;Bemis and Bemis 2015;Ellis et al 2016).…”

“…Like most teleost fishes, cichlids possess two toothed jaws, the oral and the pharyngeal jaws (Fig. lA), and tend to replace their teeth on both jaws approximately once every lOOdays throughout their Jives (Streelman et al 2003;Mehta and Wainwright 2007;Hulsey 2009;Fraser et al 2013;Ellis et al 2016;Hulsey et al 2017;Karagic et al 2020aKaragic et al , 2020b. Cichlids' oral jaws are primarily used to capture prey and are largely homologous to mammalian jaws (Wainwright et al 2001).…”

Diversity in the internal functional feeding elements of sympatric morphs of Arctic charr (Salvelinus alpinus)

“…Morphological adaptations in functional feeding elements are associated with rapid diversification of ecology in many vertebrate groups, sometimes resulting in specialization on diverse prey types within lineages (Gidmark et al, 2019; Grant & Grant, 2003). The development of these feeding elements is influenced by an interplay of genes and environmental factors during ontogeny (e.g., Karagic et al, 2020). Additionally, developmental remodelling can accommodate ontogenetic niche shifts, for instance within fishes (Gidmark et al, 2019; Karagic et al, 2020), and may contribute to intraspecific and interspecific variation in adult morphology.…”

Unique damage‐related, gap‐filling tooth replacement in pycnodont fishes

“…This phenomenon is becoming increasingly recognized for its contribution to evolution; for a literature review focusing on vertebrate dentitions see Karagic et al . (2020). Adaptive change occurs in the pharyngeal jaws of the cichlids which, like the Pycnodus vomers and prearticulars, have a crushing function.…”