Publications

2020
Ferrão, M., et al., 2020. A new species of Dendropsophus (Anura, Hylidae) from southwestern Amazonia with a green bilobate vocal sac. ZooKeys , 942 , pp. 77.Abstract
Recent studies have shown that species diversity of the South American frog genus Dendropsophus is significantly underestimated, especially in Amazonia. Herein, through integrative taxonomy a new species of Dendropsophus from the east bank of the upper Madeira River, Brazil is described. Based on molecular phylogenetic and morphological analyses, the new species is referred to the D. microcephalus species group, where it is differentiated from its congeners mainly by having a green bilobate vocal sac and an advertisement call comprising 1–4 monophasic notes emitted with a dominant frequency of 8,979–9,606 Hz. Based on intensive sampling conducted in the study area over the last ten years, the new species is restricted to the east bank of the upper Madeira River, although its geographic range is expected to include Bolivian forests close to the type locality.
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Olea, G.P., et al., 2020. Descriptions of five new species of the salamander genus Chiropterotriton (Caudata: Plethodontidae) from eastern Mexico and the status of three currently recognized taxa. PeerJ , 8 (e8800). PDF
Senevirathne, G., et al., 2020. Ontogeny of the anuran urostyle and the developmental context of the evolutionary novelty. PNAS , 117 (6) , pp. 3034-3044. PDF
Maddin, H.C., et al., 2020. Development and evolution of the tetrapod skull-neck boundary. Biological Reviews , 95 , pp. 573-591.Abstract

 The origin and evolution of the vertebrate skull have been topics of intense study for more than two centuries. Whereas early theories of skull origin, such as the infl uential vertebral theory, have been largely refuted with respect to the anterior (pre-otic) region of the skull, the posterior (post-otic) region is known to be derived from the anteriormost paraxial segments, i.e. the somites. Here we review the morphology and development of the occiput in both living and extinct tetrapods, taking into account revised knowledge of skull development by augmenting historical accounts with recent data. When occipital composition is evaluated relative to its position along the neural axis, and specifi cally to the hypoglossal nerve complex, much of the apparent interspecifi c variation in the location of the skull– neck boundary stabilizes in a phylogenetically informative way. Based on this criterion, three distinct conditions are identifi ed in (i ) frogs, (ii ) salamanders and caecilians, and (iii ) amniotes. The position of the posteriormost occipital segment relative to the hypoglossal nerve is key to understanding the evolution of the posterior limit of the skull. By using cranial foramina as osteological proxies of the hypoglossal nerve, a survey of fossil taxa reveals the amniote condition to be present at the base of Tetrapoda. This result challenges traditional theories of cranial evolution, which posit translocation of the occiput to a more posterior location in amniotes relative to lissamphibians (frogs, salamanders, caecilians), and instead supports the largely overlooked hypothesis that the reduced occiput in lissamphibians is secondarily derived. Recent advances in our understanding of the genetic basis of axial patterning and its regulation in amniotes support the hypothesis that the lissamphibian occipital form may have arisen as the product of a homeotic shift in segment fate from an amniote-like condition.

Key words : skull, development, tetrapod, occiput, somites, skull– neck, homeotic transformation

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2015
Meegaskumbura, M., et al., 2015. Patterns of reproductive-mode evolution in Old World tree frogs (Anura, Rhacophoridae). Zoologica Scripta , doi:10.1111/zsc.12121. PDF
McPhillips, T., et al., 2015. YesWorkflow: A User-Oriented, Language-Independent Tool for Recovering Workflow Information from Scripts. International Journal for Digital Curation , 10 , pp. 298-313. PDF
Sefton, E.M., Piekarski, N. & Hanken, J., 2015. Dual embryonic origin and patterning of the pharyngeal skeleton in the axolotl (Ambystoma mexicanum). Evolution & Development , 17 , pp. 175-184. PDF
Jennings, D.H., Evans, B. & Hanken, J., 2015. Development of neuroendocrine components of the thyroid axis in the direct-devoloping frog Eleutherodactylus coqui: formation of the median eminence and the onset of pituitary TSH production. Gen. Comp. Endocrinol. , 214 , pp. 62-67. PDF
Hanken, J., 2015. Is heterochrony still an effective paradigm for contemporary studies of evo-devo?. In A. C. Love, ed. Conceptual Change in Biology: Scientific and Philosophical Perspectives on Evolution and Development. Boston Studies in the Philosophy and History of Science. Berlin. Berlin: Springer-Verlag, pp. 97-110. PDF
2014
Hanken, J., 2014. Review of A. Channing, M.-O. Rödel, and J. Channing, Tadpoles of Africa: The Biology and Identification of all Known Tadpoles in Sub-Saharan Africa. Copeia , 2014 , pp. 400-402. PDF
Song, T., et al., 2014. Toward automated design, analysis, and optimization of declarative curation workflows. Internat. J. Dig. Curat. , 9 , pp. 111-122. PDF
Piekarski, N., Gross, J.B. & Hanken, J., 2014. Evolutionary innovation and conservation in the embryonic derivation of the vertebrate skull. Nature Communications , 5 , pp. 5661.Abstract

Development of the vertebrate skull has been studied intensively for more than 150 years, yet many essential features remain unresolved. One such feature is the extent to which embryonic derivation of individual bones is evolutionarily conserved or labile. We perform long-term fate mapping using GFP-transgenic axolotl and Xenopus laevis to document the contribution of individual cranial neural crest streams to the osteocranium in these amphibians. Here we show that the axolotl pattern is strikingly similar to that in amniotes; it likely represents the ancestral condition for tetrapods. Unexpectedly, the pattern in Xenopus is much different; it may constitute a unique condition that evolved after anurans diverged from other amphibians. Such changes reveal an unappreciated relation between life history evolution and cranial development and exemplify 'developmental system drift', in which interspecific divergence in developmental processes that underlie homologous characters occurs with little or no concomitant change in the adult phenotype.

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Cook, J.A., et al., 2014. Natural History Collections as Emerging Resources for InnovativeEducation. Bioscience , 64 , pp. 725-734.Abstract

There is an emerging consensus that undergraduate biology education in the United States is at a crucial juncture, especially as we acknowledge the need to train a new generation of scientists to meet looming environmental and health crises. Digital resources for biology now available online provide an opportunity to transform biology curricula to include more authentic and inquiry-driven educational experiences. Digitized natural history collections have become tremendous assets for research in environmental and health sciences, but, to date, these data remain largely untapped by educators. Natural history collections have the potential to help transform undergraduate science education from passive learning into an active exploration of the natural world, including the exploration of the complex relationships among environmental conditions, biodiversity, and human well-being. By incorporating natural history specimens and their associated data into undergraduate curricula, educators can promote participatory learning and foster an understanding of essential interactions between organisms and their environments.

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2013
2013. Implementation plan for the Network Integrated Biocollections Alliance. American Institute of Biological Sciences.

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