Tetsuto Miyashita

Tetsuto Miyashita

Postdoctoral Researcher


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Google Scholar Citations


Alfred Sherwood Romer once observed:

“In vertebrate paleontology, increasing knowledge leads to triumphant loss of clarity.”

What underlies this aphorism?  We tend find a rescue in the old chant perhaps too readily. “More specimens are needed to resolve this conflict,” “Another experiment will test the hypothesis unambiguously” — instead of saying: “Be prepared to get even more confused.”

My primary research interest — broadly themed, vertebrate origins and early evolution — is a great puzzle. Like a baseball pitcher learning to throw fastballs and curveballs, I have developed independent lines of inquiry in fossils and embryos, connected by the threads of phylogenetically informed anatomical comparison. Recently, we showed a path to reconcile conflicting evidence between fossil/morphological and genetic/molecular data at the base of the vertebrate tree (Miyashita et al., 2019). This new phylogeny of vertebrates places hagfish and lampreys in their own natural group Cyclostomi, but also suggests the lineages typically considered stem gnathostomes — anaspids and conodonts — are stem cyclostomes. The implication is that the last common ancestor of all living vertebrates already had mineralized skeletons. We are dissecting the new phylogeny using ontogenetic information from fossil jawless vertebrates and other lines of inferences for their elusive soft-tissue anatomy.

As for the curveballs, my research in developmental biology relies heavily on collaborations with the zebrafish labs (Victoria Prince and Ted Allison), the hemichordate lab (Chris Lowe), and the lamprey lab (Marianne Bronner). My aim is to provide phylogenetically robust comparison of development on key anatomical features of vertebrates, such as the mandibular arch, isthmus, and hypobranchial muscles. Comparative work takes place at the Marine Biological Laboratory for hemichordates and California Institute of Technology for lampreys, whereas much of experimental work using zebrafish is conducted in Chicago. As a side project, we are also investigating what superficially looks like an atavistic, agnathan-like trait in zebrafish mutants, hoping to gain evolutionary insights about developmental plasticity. These approaches together, I hope to uncover the interplay of ontogeny and phylogeny in vertebrate origins and early evolution.

In my spare time, I work on finer-level questions on more charismatic organisms, including dinosaurs. My non-early vertebrate research comes from two academic roots of mine in research assistantship with Philip Currie since my high school days spent in Drumheller, Alberta, and several field seasons spent in marine labs as an undergraduate/graduate researcher under the supervision of Richard Palmer. So my research interest is broad, and my approach is a bit new and mostly old. Although there is no such thing as a wholly new approach in research, Thelonious Monk has something to say about that:

“It can’t be any new note. When you look at the keyboard, all the notes are there already. But if you mean a note enough, it will sound different.”