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
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.

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.

2013. Implementation plan for the Network Integrated Biocollections Alliance. American Institute of Biological Sciences.
Hanken, J., 2013. A scientist in full: the fruitful, flawed Louis Agassiz [review of C. Irmscher, Louis Agassiz: Creator of American Science]. Harvard Magazine , 115 , pp. 22-24. PDF
Rovito, S.M., et al., 2013. Adaptive radiation in miniature: the minute salamanders of the Mexican highlands (Amphibia: Plethodontidae: Thorius). Biological Journal of the Linnean Society , 109 , pp. 622-643.Abstract

The small size and apparent external morphological similarity of the minute salamanders of the genus Thorius have long hindered evolutionary studies of the group. We estimate gene and species trees within the genus using mitochondrial and nuclear DNA from nearly all named and many candidate species and find three main clades. We use this phylogenetic hypothesis to examine patterns of morphological evolution and species coexistence across central and southern Mexico and to test alternative hypotheses of lineage divergence with and without ecomorphological divergence. Sympatric species differ in body size more than expected after accounting for phylogenetic relationship, and morphological traits show no significant phylogenetic signal. Sympatric species tend to differ in a combination of body size, presence or absence of maxillary teeth, and relative limb or tail length, even when they are close relatives. Sister species of Thorius tend to occupy climatically similar environments, which suggests that divergence across climatic gradients does not drive species formation in the genus. Rather than being an example of cryptic species formation, Thorius more closely resembles an adaptive radiation, with ecomorphological divergence that is bounded by organism-level constraints.(c) 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109, 622-643.

Hanken, J., 2013. Biodiversity Online: Toward a Network Integrated Biocollections Alliance. Bioscience , 63 , pp. 789-790. PDF
Bloom, S., et al., 2013. Developmental origins of a novel gut morphology in frogs. Evolution & Development , 15 , pp. 213-223.Abstract

Phenotypic variation is a prerequisite for evolution by natural selection, yet the processes that give rise to the novel morphologies upon which selection acts are poorly understood. We employed a chemical genetic screen to identify developmental changes capable of generating ecologically relevant morphological variation as observed among extant species. Specifically, we assayed for exogenously applied small molecules capable of transforming the ancestral larval foregut of the herbivorous Xenopus laevis to resemble the derived larval foregut of the carnivorous Lepidobatrachus laevis. Appropriately, the small molecules that demonstrate this capacity modulate conserved morphogenetic pathways involved in gut development, including downregulation of retinoic acid (RA) signaling. Identical manipulation of RA signaling in a species that is more closely related to Lepidobatrachus, Ceratophrys cranwelli, yielded even more similar transformations, corroborating the relevance of RA signaling variation in interspecific morphological change. Finally, we were able to recover the ancestral gut phenotype in Lepidobatrachus by performing a reverse chemical manipulation to upregulate RA signaling, providing strong evidence that modifications to this specific pathway promoted the emergence of a lineage-specific phenotypic novelty. Interestingly, our screen also revealed pathways that have not yet been implicated in early gut morphogenesis, such as thyroid hormone signaling. In general, the chemical genetic screen may be a valuable tool for identifying developmental mechanisms that underlie ecologically and evolutionarily relevant phenotypic variation.