Biology subjects

Portela-Miguez, R.

Publications and source records attributed to Portela-Miguez, R..

3 recordsLinked to original sources

bioRxiv2025

Dental calculus formation is linked to diet and phylogeny in mammals

O_LIAs a point of entry, the oral cavity serves as a potential first area of colonization of the host with environmental bacteria. As such, the oral microbial community not only affects a wide range of internal host processes, including health and digestion but may also reflect the external environment and ecology of the host. C_LIO_LIDental calculus, a mineralized form of dental plaque, preserves the DNA of the host microbiome through time, serving as a rich source of historical microbiota. Despite its potential to provide temporal information on the ecological and evolutionary processes of microbiomes, dental calculus has rarely been explored outside of humans and non-human primates. Hence, it remains unclear how ubiquitous it is across mammals. C_LIO_LIUsing natural history museum collections, we surveyed > 1600 specimens belonging to 142 species, representative of every mammalian order, to investigate the taxonomic distribution of dental calculus, and to identify factors that most strongly contribute to its formation. We found dental calculus to be abundant across mammalian taxa, with 104 of the surveyed species showing calculus deposits. C_LIO_LIHigh fiber diets were most strongly associated with calculus presence and abundance, whereas species with high protein and fat diets showed little to no calculus deposits. We also found evidence of phylogenetic signal in calculus formation, pointing to the effects of oral/dental morphology. In addition, captivity strongly affected dental calculus formation in almost all dietary categories. Using this information, we made predictions about the likelihood of finding dental calculus in unsurveyed mammalian species, with the aim of informing future investigations. C_LIO_LIOur study found that dental calculus is readily available in natural history museum collections, making it an easily accessible source of oral microbiota from wild animals. We highlight the taxonomic diversity of species presenting dental calculus and provide information and suggestions to researchers and museum curators interested in utilizing dental calculus for the study of oral microbiota, past and present. C_LI

ecology↗

bioRxiv2022

Testing heterochrony: Connecting skull shape ontogeny and evolution of feeding adaptations in baleen whales

Ontogeny plays a key role in the evolution of organisms, as changes during the complex processes of development can allow for new traits to arise. Identifying changes in ontogenetic allometry - the relationship between skull shape and size during growth - can reveal the processes underlying major evolutionary transformations. Baleen whales (Mysticeti, Cetacea) underwent major morphological changes in transitioning from their ancestral raptorial feeding mode to the three specialised filter feeding modes observed in extant taxa. Heterochronic processes have been implicated in the evolution of these feeding modes, and their associated specialised cranial morphologies, but their role has never been tested with quantitative data. Here, we quantified skull shapes ontogeny and reconstructed ancestral allometric trajectories using 3D geometric morphometrics and phylogenetic comparative methods on sample representing modern mysticetes diversity. Our results demonstrate that Mysticeti, while having a common developmental trajectory, present distinct cranial shapes from early in their ontogeny corresponding to their different feeding ecologies. Size is the main driver of shape disparity across mysticetes. Disparate heterochronic processes are evident in the evolution of the group: skim feeders present accelerated growth relative to the ancestral nodes, while Balaenopteridae have overall slower growth, or paedomorphosis. The grey whale is the only taxon with a relatively faster rate of growth in this group, which might be connected to its unique benthic feeding strategy. Reconstructed ancestral allometries and related skull shapes indicate that extinct taxa used less specialized filter feeding modes, a finding broadly in line with the available fossil evidence.

evolutionary biology↗

bioRxiv2022

The ontogeny of asymmetry in echolocating whales

Extreme asymmetry of the skull is one of the most distinctive traits that characterizes toothed whales (Odontoceti, Cetacea). The origin and function of cranial asymmetry are connected to the evolution of echolocation, the ability to use high frequency sounds to navigate the surrounding environment. Although this novel phenotype must arise through changes in cranial development, the ontogeny of cetacean asymmetry has never been investigated. Here we use three-dimensional geometric morphometric to quantify the changes in degree of asymmetry and skull shape during prenatal and postnatal ontogeny for five genera spanning odontocete diversity (oceanic dolphins, porpoises, and beluga). Asymmetry in early ontogeny starts low and tracks phylogenetic relatedness of taxa. Distantly-related taxa that share aspects of their ecology overwrite these initial differences via heterochronic shifts, ultimately converging on comparable high levels of skull asymmetry. Porpoises maintain low levels of asymmetry into maturity and present a decelerated rate of growth, likely retained from the ancestral condition. Ancestral state reconstruction of allometric trajectories demonstrates that both paedomorphism and peramorphism contribute to cranial shape diversity across odontocetes. This study provides a striking example of how divergent developmental pathways can produce convergent ecological adaptations, even for some of the most unusual phenotypes exhibited among vertebrates.

evolutionary biology↗