2019 Science Innovation Award Citation & Response

Tim Lyons, citationist for Ariel Anbar

Citation by Tim Lyons

Ariel Anbar and I have been collaborators and friends for twenty years. We’ve co-mentored postdocs and graduate students, shared many grants small and large, traveled to distant field locations, and co-published many papers always with the central theme of deconstructing the early co-evolution of life and its environments. From this vantage I can speak confidently about Ariel’s many contributions and their profound impact on biogeochemistry, geobiology, astrobiology, isotope geochemistry, science education, team building, and community service and leadership. I am both delighted and honored to introduce Ariel as the 2019 recipient of the EAG Science Innovation Award.

Ariel is and will long be known for many important projects and papers—far beyond what I can discuss here. He was a pioneer in the early development and application of novel (heavy metal) stable isotope approaches, and his initial challenging measurements and clever applications, along with those from a few other brave innovators, yielded unimagined fruit and defined an entire field of research. For example, we cannot think of iron isotopes without harkening back to the early days and Ariel’s rigorous method development and his fundamental challenge to claims that iron isotopes would provide simple signatures of ancient or distant life.

Ariel begged the community to carefully consider the myriad possible controls on complex systems and to interpret with caution and creativity—and always with big questions in mind. He showed us the way with iron and, in the process, defined a path for rigorous proxy development that was extrapolated in rapid succession to wide-ranging novel isotope systems. The world of isotope geochemistry entered a new era made possible by new instruments in the hands of an upper echelon of geochemists. Ariel was at the center of that cohort and became the frontrunner in applications to Earth’s early redox history.

Ariel’s greatest hits include his frontier-defining studies of molybdenum isotopes. I was thrilled to work with him in this area, and it was immediately clear that molybdenum, once understood mechanistically, could provide global perspectives on the evolving oxygen state of the early oceans. He recognized that calibration would require measurements in modern analog settings along with careful experimental simulations. He laid out a roadmap for best practices that we still follow today.

Those early molybdenum isotope data corroborated one of the major propositions in Precambrian geobiology—that is, Don Canfield’s vision in 1998 of a deep ocean that remained oxygen-free for almost two billion years after O2 first accumulated meaningfully in the atmosphere. Ariel was keen to test this theory in 2004 with Gail Arnold and colleagues using molybdenum isotopes. Only a couple of years earlier, in 2002, he and Andy Knoll suggested that anoxic waters may have stripped the oceans of trace metal micronutrients that are essential for broad ranging biological processes, including microbial nitrogen cycling. And those limitations may have helped mute the early rise of O2 and delay the emergence and proliferation of complex life. Anbar and Knoll (2002) set the stage for volumes of research—ranging from additional novel geochemistry to experimental microbiology.

Ariel’s leadership with molybdenum led him to many major contributions to our understanding of early oxygen in the oceans and atmosphere, including the highly cited Anbar et al. (2007) and Scott et al. (2008), which set into motion a sea of studies addressing the Great Oxidation Event and Earth’s redox landscape before (think ‘whiffs’ of oxygen) and after (as in the famous ‘boring billion’). He built teams through coordination of sample collection and curation. And he, more than anyone else, took on the difficult task of weaving together disparate research communities so that evolution of the solid-Earth could finally be linked to conditions in Earth’s shallowest layers. The bridges he built spanned from mantle dynamics and petrology to atmospheric chemistry. He has always understood better than most the connections among the oceans, atmosphere, and life—and Earth’s interior.

Ariel’s impact is defined by creating a culture of colleagues and facilities that fosters isotope innovation in a team-collaborative way (viewing innovation, in his words, as a team sport). Within that space at ASU, Ariel identified the need for proxies that could open up the carbonate rock record, and uranium isotopes became the target. The net result was a series of landmark studies of the Permo-Triassic boundary and other key intervals in Earth history. In many ways, Ariel was one of the initial few who put multi-collector ICP-MS technology on the map. I would add to the mix his very recent explorations of the thallium and mercury isotope systems and his work with calcium—most notably as a tracer of bone mineral balance during human space exploration.

Ariel delights in creating something fundamentally new and then watching it ripen and mature within the biogeochemical community while he moves on to plant the next seed. Indeed, his greatest satisfaction comes with innovation. I understand his thinking, but I also know he undersells the huge additional impact his longer-term, follow-up research has had.

This award is a wonderful way of thanking Ariel for his bold choices and all their subsequent value, including his unprecedented efforts in innovative teaching. And now, at the highest level, Ariel is showing us how to use Earth history to explore for life beyond our solar system. His level of service to the community, and early career scientists in particular, should be embraced and emulated.

Finally, I know the connection between this year’s award and Sam Epstein, one of his early mentors, humbles and delights Ariel. He once told me that he imagines his gamble on nontraditional stable isotopes as a kind of tribute to Sam.

I am hard pressed to think of another scientist who does so many things so well and with such grace and generosity. He is as clever as he is hardworking and as savvy as he is smart. And fittingly he is the 2019 recipient of the Science Innovation Award. It is my great honor to introduce Ariel Anbar.

Timothy Lyons

Response by Ariel Anbar

How I learned to stop worrying and love mass spectrometry.

Thanks, Tim. This is a humbling honor, most especially because the award is named after Sam Epstein, who was one of my heroes.

Tim, I owe you so much – my long time collaborator, counselor, and teacher.

I owe so much to so many others… most especially to those who I have had the good fortune to mentor in my labs at Rochester and ASU. Some are now my mentors, as it should be. Many of them are here – thanks to each of you. You are the engine of inspiration and innovation.

And to my family – especially Marni and my kids, Nathaniel and Naomi, who are here, and to my parents, and my brother and his family… To avoid saying anything trite I’ll simply say “there are no words”.

I owe so much to so many… when I was notified about this award I made a list and it’s insanely long. I tried to work in key people from my professional life into the biography posted on the EAG website – please check that out if you are interested – but as I ran into old friends at the reception last night I realized that even that is terribly incomplete. I already asked if I can revise it!

So instead of reading a long list of people to thank I want to spend the remaining few minutes telling you all a bit about Sam Epstein and how he influenced me. Not just through his science but through who he was as a person. You might call this a little story about ‘how I learned to stop worrying and love isotope geochemistry’ because of Sam. It’s my way of trying to repay a huge debt of thanks that I owe him.

I think Sam was the first Caltech professor I ever met, when I was still a prospective student visiting the campus. I was drawn to Caltech because of its reputation for innovation, although I had no idea what that meant. That early meeting with Sam inspired me and so I a few months later I found myself in his office again, a first year student trying to figure out what I would do. I was pretty wound up about it – like so many students I felt the specific decisions I made would shape my life and so I had to get them right. And I knew above all that I wanted to do something new. I was looking for that unicorn – an “innovative project” that would make my career.

Sam was already retirement age at that point – about 70 – but he had a youthful twinkle in his eye. He suggested that I work for him because there was so much still to do with stable isotopes. He wasn’t taking on new students at that point but as he talked about all the great science that could still be done I could see him trying to figure out how it might work.

I knew a bit about stable isotopes from my father – also a scientist. A chemist. Not a geochemist but he knew Sam and some of the other players and was known to them because he had run a big mass spectrometry group a few years earlier at SRI. My father and I got along just fine but I wanted to blaze my own trail.

“Prof Epstein,” I said “I am not sure I know what I want to do, but I know what I DON’T want to do. I don’t want to do mass spectrometry, because that is what my father did. It is old fashioned” I said before realizing that saying this might be kind of rude. Also, maybe a bit stupid considering what Caltech was known for in geochemistry – which at the time I clearly didn’t understand! I remember Sam looked a bit hurt. But he didn’t try to argue.

But I think it was at the same meeting that Sam got me thinking differently, in a really subtle way. He had recently officially retired and they’d thrown a big party for him. There were some poster-sized prints of him that were now stacked in a corner. The one on top was of him a few years older than I was at that time. About the time that Sam finished grad school. He looked kind of wistfully at that photo. “That guy was so lost”, he said. “What do you mean?” I asked. “He had no idea what he wanted to do.”

Ariel Anbar (right) receiving the 2019 Science Innovation Award from Sigurdur Gislason, EAG President

I later learned that Sam’s graduate work had nothing to do with geoscience or the environment. It was wartime and he was enmeshed in nuclear research tied to the war. He only really found his calling after grad school, as a postdoc with Harold Urey at the University of Chicago. He never had that “perfect dissertation” that I was stressing over, but it had worked out pretty well for him! That told me that what I did for my dissertation was maybe not so critical. It would not have to determine the rest of my life. This was a quiet revelation.

I wanted to be innovative but I was thinking about it all wrong. The point of “innovation” is to be willing and able to shift gears often as interest and opportunity arise. It isn’t about picking something innovative and doing that thing forever. That is in fact the path to a new routine not to innovation.

I started to see mass spectrometry and isotope geochemistry in a new light. These fields had been around a long time, true, but that didn’t make them “old fashioned”. They lasted because they were so versatile – because they were powerful tools for innovation. An isotope geochemist can shift from one problem to another in ways few scientists can, developing new tricks and applying new insights to tackle ever more types of problems. We isotope geochemists are super fortunate in that we never have to specialize. We never really have to grow up. We are like the Peter Pans of geoscience. Always staying young and trying new things.

I learned that first from Sam. Maybe that is why even as an old man he always had that youthful twinkle in his eye.

Thank you.

Ariel Anbar