My two favorite publications of all time

Marilyn and Mat Wooller in Belize-did we have a rigorous hypothesis?

            In 1980, I shared my office with visiting professor Dave Freeman, University of Maryland (Dave is Kate Freeman’s dad!). He was at a critical time in his career and wanted to assess where he’d been and what he’d accomplished.

            Reading over a list of his publications, he said, “Do you know what your best five publications are?”

            “Sure,” I said quickly. At that point in time, I only had 5 publications. It wasn’t difficult at all. Now with over 200 and some papers, a few stand out.

            The first one was published in 1999:

 Fogel, M. L., and N. Tuross, 1999. Transformation of plant biochemicals to geological macromolecules during early diagenesis. Oecologia 120:  336-346.

            I had been asked to give the keynote address to the first international meeting on isotope ecology—IsoEcol 1998. It was presented in the days before Powerpoint projectors were used. I had both photographic slides and overhead transparencies that I had made to give the talk.

            I was fascinated by new molecular techniques that my colleague Noreen Tuross was experimenting with at the Smithsonian Institution. When Noreen took a leave of absence to run the Watson Foundation, I spent a sabbatical in her lab learning Western blots, protein gels, and immunology. At that time, my husband was the Director of the Jug Bay Wetlands Sanctuary on the Patuxent River in Maryland. Every year, I’d watched the rapid growth of marsh plants in spring and summer, followed by their senescence in early fall. My family spent every weekend there for almost 8 years. I decided to design a litterbag experiment, similar to the ones I’d worked on with Ron Benner. My goal was to combine molecular biology, litterbags, and stable isotopes. I learned a lot doing this!

         Understanding the role of microorganisms in influencing sedimentary organic matter evolved rapidly in the 1980s. Today, there are more studies of the structure and isotopic compositions of microbial biomarkers and molecules than there are of compounds from higher plants (e.g. Schouten et al., 2013; Hopmans et al., 2004; Schouten et al., 2002).

         Plants were collected from the marsh in early September. I had a high school intern who was assigned the task of sewing the plants once they were dried and weighed, into mesh bags. Alex Feldman was not used to sewing, to put it mildly, but he learned rapidly and developed a unique style that looked nothing like how a matron like myself would sew. The bags were either buried in deep marsh muck or tethered to PVC pipes, where they sat on the sediment surface. Monthly, I would don hip waders and muck through the mud to pull out a couple of bags of rotting plants.

         It was a labor of love. As Ron Benner would say, “It’s like money in the bank.” The decomposed plants were gently washed free of sediment, dried, weighed, then  ground into a fine powder. I had hundreds of samples from this experiment. Next, we prepared them for “ash free dry weight”, a tedious measurement to quantify how much sediment was stuck to the plants that we couldn’t see. It was important for determining mass balance.

         Next we weighed out a milligram or two and determined the % carbon and nitrogen and the isotopic composition of each sample. The experiment was followed for about 500 days. During that time, I not only carried out the work, but also gave birth to my son, Evan. When he was a baby, Chris and I went together. I carried Evan in a front pack, while Chris did the marsh mucking for me. He would throw the samples from the marsh to me, standing on the dock. Once, there was a very near spill of young master Evan into the Patuxent River! We were more careful after that. 

Marilyn getting litter bags, circa 1991

 

         I also followed the progression of decomposition in my samples with compound specific isotope analysis (CSIA) using gas-chromatography-combustion-continuous flow methods, which had been used in my lab for about 5 years. Noreen Tuross taught me how to conduct ELISA (enzyme linked immunosorbant assay) using two monoclonal antibodies developed for the enzyme Rubisco and a lab-synthesized humic acid, a type of geo-polymer found in sediments. I tried out the modern techniques in protein purification and Western blotting, which visualized pieces of decomposed plant fragments by reaction with specific antibodies.

Black "bands" show proteins in fresh (upper panel) and rotted plants (lower panel)

         I was still fascinated with Rubisco and was curious how this major plant protein degraded along with the other major plant biochemicals.  In non-woody herbaceous plants, Rubisco declined by 40-80% in three months time, but we could still detect intact high molecular weight, 55,000 dalton Rubisco subunits (Fogel and Tuross, 1999). In upland plants with thicker, waxy leaves (e.g., mountain laurel), 80% of the original Rubisco remained intact after one year of incubation in anaerobic sediments. One of the plants I included in the experiment was leaves from locally grown corn plants. Corn, a C₄ plant, was incubated in the C₃ plant environment of the wetland. My hypothesis was that over time, I would be able to detect carbon isotope shifts from corn’s C₄ values to C₃ values originating from organic matter in the wetland. In fact, this indeed happened.

Methods of Western blots and isotopes: a first

         For the first time, and to my knowledge the only time, I purified the different subunits of Rubisco from fresh corn, then measured the carbon isotopes in the amino acids from the two subunits, as well as the amino acids in the bulk corn tissue. We found that the carbon isotopes in amino acids in purified Rubisco subunits had different compositions with respect to bulk protein. In addition, the amino acids within large and the small units in fresh Rubisco had different isotope signatures from each other. The small subunit is coded by a gene in the nucleus but is synthesized in the cytoplasm primarily in leaf tissue, as well as in stems and petals. The large subunit, however, is coded by a gene in the chloroplast and is synthesized within the chloroplast. The complete Rubisco molecule is assembled after the small subunit is imported into the chloroplast (Gutteridge and Gantenby, 1995). Thus, it is not surprising that the carbon isotopes of individual amino acids from each subunit should have different isotopic compositions.

            We also compared the isotope pattern of fresh plant material with decayed plant material. The simpler amino acids (e.g., serine, glycine, alanine) have more positive carbon isotope values, whereas the more complex ones (e.g. valine, leucine, phenylalanine) have more negative values (Fogel and Tuross, 2002). For geochemical studies, a sample’s amino acid fingerprint--the relative differences in carbon isotopes among amino acids--could be altered during microbial decomposition either by the preferential breakdown of amino acids or addition of microbial proteins leading to a heterogeneous mixture.

            When I presented the work to Ron Benner’s lab in Texas, he had one of his generally abrupt comments, “This work is kind of crude,” he remarked. Fortunately, I understood that he meant that I’d only measured the proteins and amino acids, and not the lipids and carbohydrates. Noreen and I learned what it takes to do something completely different like this. Although I didn’t repeat that type of study, I am proud of it today.

            My second favorite publication came from the investigations in Belize:

Fogel, M. L., M. J. Wooller, J. Cheeseman,  B. J. Smallwood, Q. Roberts, I. Romero,  and M. Jacobson Meyers,  2007. Unusually negative nitrogen isotopic compositions of mangroves and lichens in an oligotrophic, microbially-influenced ecosystem. Biogeosciences 5: 1639-1704. I described the work earlier, but want to tell the story of its publication.

         I submitted the first manuscript to the journal Biogeochemistry. It was long, had many figures, and was written in the historic way in which I figured out why we had measured such unusual isotope compositions in mangrove leaves. The paper was roundly rejected! 

“The manuscript suffers from unfocused objectives and poor organization. The dataset offers potential to address several objectives.  However, addressing them all within a single paper is not likely to complement the strengths of this dataset and rather detracts from a central message.”

More complicated studies often get reviews like this. A second review noted the following:

         “The data are interesting, overall — but I am not persuaded by the authors' conclusions based on their interpretation of the data. In particular, I am bit concerned that the authors' arguments for substantial uptake of NH₃ gas might not be plausible when put in the context of annual plant N demands and isotope mass balance. Moreover, the hypotheses put forth are not sufficiently teased apart by the authors; the manuscript comes across as very speculative at times… I would strongly urge the authors to identify a more rigorous question based approach, which provides mutually exclusive hypotheses and corollaries that are followed through to the end of the manuscript… The results section is way too long. It wanders considerably, filling the reader with information that is tangential to the manuscript. I would strongly recommend that the authors remove data and discussions of C isotopes from this manuscript, and focus on the N isotope patterns as they relate to foliage. ”

         What could we do? The work was finished, the data—thousands of data points—were collected. For young scientists, the message is—don’t give up!

            I revamped the manuscript, sent it out again, and once again, the work was criticized and viewed not publishable. It was a complete shock. In science, manuscripts are reviewed by our peers—it was clear to me that someone did not want the work published. Given the fact that I had ended the mangrove study on a sour note, it troubled me to think that those problems might have spilled over to publishing our findings.

            In response to this, the 3^rd version of the paper was submitted to the journal Biogeosciences, a journal that publishes not only the manuscript, but the reviews, and my response to those reviews. Interestingly, the reviews were now positive, non-personal, and the paper was accepted quickly. Isotope and mangrove expert Steve Bouillon wrote:

“The authors reasonably argue that ammonia from the atmosphere and in rainwater are likely important N sources, and that the d¹⁵N signatures observed in mangrove leaves reflect a balance between these N sources and N uptake from sediment porewaters. This balance is also demonstrated to be governed by the availability of P in this P-limited system. The paper is a nice contribution to our understanding of N cycling in mangrove systems, and relevant more generally for our understanding of N isotope patterns in vegetation and its utility to understand ecosystem nutrient cycling. I recommend publication in Biogeosciences, although the ms. could be improved if a number of issues are clarified.”

            Ecologist and isotope scientist Erik Hobbie wrote:

“Overall, the paper makes a solid case that several mechanisms other than soil N source isotopic signatures and mycorrhizal processes may control plant ¹⁵N patterns in mangrove systems. This paper points the way towards quantitative assessment of plant-atmosphere N fluxes as one fruitful avenue for providing us with a more complete picture of the causes of plant isotopic patterns.”

I think this is a great model for peer review—the reviewers here chose to reveal themselves and their reviews. Gone were the preachy reviews described above telling me to come up with a more rigorous hypothesis. If nothing else, I learned to be as polite as possible in a review and try to always hope to bring out the best in others’ work.

I've had great mentors and learned how to be one

Maxine Singer, President of Carnegie Instituion (l) and Charlie Prewitt , Geophysical Lab Director (r), 1987

            Mentoring wasn’t something that happened overtly when I was “growing up” in my career. Dr. Peter Given at Penn State was my first mentor. He was thoughtful in just about every way: provided an opportunity to do research in his organic geochemistry lab, taught a great course, and helped me get into a good graduate school. I kept in touch with him until he passed way in 1988. He was instrumental in promoting my career by inviting me to give a presentation on my work with isotopes in hot springs at a Gordon Conference in 1982. In hindsight, he mentored me for well over ten years!

            My Ph.D. advisors at the University of Texas were “silent” mentors. I may sound oblivious, but I wasn’t really aware they were paying attention to me until after I’d gotten my degree and arrived at the Carnegie. Their mentorship was more behind-the-scenes sort of advice, subtle encouragement, and unity in seeing I advanced when I was ready. They wrote a lot of letters of recommendation for me when I was looking for my first job after a postdoc. Chase van Baalen died fairly young, but Pat Parker mentored me until he died in 2011, making trips to DC almost every year. That’s well over 30+ years of mentoring! One of his classic lines in regards to the life of a scientist, “You’ll never be rich, but you’ll be comfortable.” His insight into mentoring grad students: “You can teach ‘em to read and write, but they have to think on their own.”

Wes and Roseanne Huntress--They held great Christmas Parties!

Hatten S. Yoder (l) and Elbert F. Osburn, 1986

            Tom Hoering was my next mentor. I’ve described him throughout my writings. His style was to sit back and observe, then offer his opinion when he thought you needed it. Oft times, I didn’t like his opinion, but by this time, I was thinking on my own, so to speak, and listened but kept my own council. By the time he passed away in 1995, we co-mentored each other. It was a good back and forth relationship that worked for both of us. I picked up the reins of Senior Mentor at the Geophysical Laboratory from him in the early 1990s.

            The Directors of the Lab also provided mentorship, albeit they were also bosses and it was their job to guide you. Hat Yoder had the heaviest hand, editing abstracts and manuscripts with an active red pencil. Charlie Prewitt was a collaborative mentor, working to develop my skills as a senior scientist. Wes Huntress mentored me with respect to gaining leadership skills. Carnegie President Maxine Singer mentored when you needed her to. Her famous phrase “Half measures never work” inspires me even today. DTM’s Director Sean Solomon provided sage advice as I considered leaving the Carnegie in 2012.

            From all these good people, I developed my own style of mentoring. I like to get to know people. I’ve learned that a person’s life outside of work can have a dramatic influence on their work in the lab. In fact, young scientists’ careers these days are shaped as much by their family situation as they are by their work situations. The two cannot be separated. The theme of work life balance has become a buzzword that we scientist write about with varying opinions.

            Should young scientists work on weekends? Late at night? More than 50 hours per week? When should they have children? Should they move with their spouse? Should they get married? Is it OK to have a relationship in your own lab? How much is private vs. public knowledge?

            Combine that with the more typical questions early career scientists have. Am I good enough? Do I really have what it takes to get a Ph.D.? Do I want an academic career? Is my advisor an asshole or just tough? Is this enough to publish? What happens when my paper’s rejected?

 

            Starting at the Carnegie, I had a “shingle” outside my door “The Doctor is IN” with a picture of the Peanuts cartoon character Lucy Van Pelt. I kept phone numbers of therapists and psychiatrists in my desk, referring out mentees when their needs exceeded my training. A box of tissues was stationed at the corner of my desk in case tears came—something that happened more than I would have liked. The best was to politely ignore the tears, while sliding the tissue box within reach. At the University of California, I learned about student health services, Title IX officers, and local therapists of potential use. Colleague Seth Newsome recommended having a stuffed animal to hand to a distressed mentee.  A small cute wombat has been passed to many a person, who calmed down stroking the little beast’s fur.

            At both UC campuses, I served as official and unofficial faculty mentor. It’s one of my more important jobs. Usually a quick chat solved most small problems. The major points of discussion centered around two topics: managing graduate students and tenure. These required ongoing, frequent conversations, often lasting a couple of hours. My strategy was to allow as much time as needed—ignoring emails and other distractions, with the exception of teaching. Without question some of the most important work I’ve done was to mentor students, postdocs, and early career scientists to be happy and productive in their life and their work.

            Now, mentoring is front and center in the academic world. It’s fully recognized now that one mentor is not enough. You need many mentors to guide through complex maze of scientific life. I call on my colleague Mary Droser, who has the sage advice of someone who’s navigated UC Riverside politics for decades. And most importantly, I rely on my husband who provides the day-to-day advice that I need to make the decisions facing me as I ease into retirement. How fortunate I am to have the support and to be able to give the support to others.

Working with Ron Benner and solving salt marsh mysteries

Ron Benner (l), Marilyn, Matt McCarthy(r), Sea Ranch, California 2018

          

My involvement in the marine science community in the 1980s encouraged me to jump into studying the fate of organic matter in the natural world —the slow breakdown of living biomass as it transforms into “goo” that ultimately may form petroleum. John Hedges of the University of Washington and Ron Benner, then a postdoc at the University of Georgia, led this research area. John Hedges, a former Geophysical Lab postdoc and Univ. of Texas Marine Science graduate, was a formidable geochemist known the world over for his careful work. At the Geophysical Lab, his reputation was colored by the stories Tom Hoering told about him. John didn’t learn much chemistry in the Port Aransas Marine Lab apparently, before coming to the Carnegie after earning his Ph.D. In the 1970s, gas chromatograph instruments cooled their furnace boxes by automatically lifting up the top of the instrument and allowing hot air to escape. Hedges rested a full cup of coffee on the top of the instrument one morning, then left the lab to talk to a colleague in his office. As luck would have it, his analytical run ended; the top of the gas chromatograph rose up; and there went his entire cup of coffee drenching the inner workings of the instrument. A rookie mistake, and one that he never outlived.

Ron Benner, 1988

         I connected with Ron Benner first by telephone regarding a potential collaboration with a graduate student from Univ. of Georgia. At the end of one conversation, he remarked, “I expect to publish the data from this work,” in a tone that implied that I might be a dilettante and not be serious! I glared at the phone and icily replied that of course, I expected to publish. When we finally met in person in 1986, Ron turned out to be a friendly, generous fellow. A tall, imposing, and ruggedly handsome man (looking remotely like the actor Omar Sharif), Ron has a way of pausing for a few seconds before answering a question. His answers come in full documents with paragraph structure and complete sentences. He’s known widely for being a tough scientist as well as a fun-loving person you’d like to have on an oceanographic expedition. We remain good friends and colleagues to this day.

         At that time (1985), one of the most contentious theories involved the role of Spartina alterniflora, a C₄ grass that dominates salt marshes in North America, for sustaining the growth of important animal species living in highly productive marsh ecosystems. Salt marshes ring the edges of bays and estuaries from Massachusetts to northern Florida. Spartina is the dominant plant that you see when you drive from the mainland in places like New Jersey or North Carolina to the outer beach islands where most tourists are headed. To me, salt marshes are some of the most beautiful places in North America for their brilliant greenness next to sparkling salty waters. Mussels, clams, crabs, and fish abound there. It would make sense to anyone looking at the ecosystem that the Spartina plants should be important contributors to their well-being and be a part of their diet.

         Carbon isotopes of organic matter in the water, Spartina, sediments, phytoplankton, and invertebrates (e.g. mussels and crabs) were measured from Woods Hole, Massachusetts, all the way down to Georgia. Every study of the isotope patterns found that the carbon isotopes in the sediments and animals in the bays had carbon isotope values closer those of phytoplankton rather than those patterns measured in Spartina.  Many concluded that Spartina was just a pretty plant and not important. The interpretation of the carbon isotope data had important implications because salt marshes were threatened habitats. The idea that salt marshes were not important contributors to food web dynamics did not make sense to me. If estuarine scientists could prove that these wetlands were nurseries and energy sources for commercial seafood, they were more likely to be protected from development.

Stable isotopes solve mystery of salt marshes, 1987

         My involvement with Spartina ecosystems began in 1985. I was contacted by Kent Sprague, a student from the University of Georgia who was studying estuarine sediment deposits from thousand year old salt marsh sediments. He came to the Geophysical Laboratory with sediment cores composed of peat—a sediment type built by the remains of plants. From these cores, he picked out fragments of nearly intact Spartina that were hundreds to thousands of years old. We measured the carbon isotope patterns of these plant fragments and found values very similar to modern bulk sediment. We used pyrolysis-gas chromatograph-mass spectrometry coupled to stable isotope analysis to provide further information on the structural and chemical composition of organic matter sources from these marshes (Fogel et al., 1989). Then, I figured out a way to estimate the sources of organic matter—either from Spartina or phytoplankton—to ancient peat sediments. Sedimentary material and plant fragments plotted firmly in the space showing that Spartina contributed roughly 50% of the organic matter in sediments. Discovering why the sediments and plant fragments from Spartina had more very different values from modern Spartina involved more work.

         Ron Benner was conducting litterbag experiments with Spartina. Dried plants are weighed, sewn into nylon or polypropylene bags with defined mesh sizes, and then incubated in the environment either under aerobic (with oxygen) or anaerobic (without oxygen) conditions.  Bags are periodically (e.g. weekly or monthly) removed from the environment, and the remaining plants in the litterbag are dried and subjected to various types of analyses. Kent encouraged Ron to write to me about analyzing the Spartina in the litterbags for carbon and nitrogen isotopic compositions. Using the bulk Spartina material, Benner used chemical methods to separate the major plant structural biochemicals: lignin, cellulose, and hemicellulose.  In 1985, Ron wrote to me:

“I welcome your suggestions and I believe that the carbon isotope measurements on the chemically fractionated material is a good one. Am I correct to assume that the carbon isotope ratios among these particular fractions (cellulose, hemicellulose, lignin) will probably be indistinguishable?”

         Samples from an 18-month experiment were brought up to the lab by Kent Sprague and analyzed using laborious, sealed-tube combustion methods. The results were striking (Benner et al., 1987). Although bulk carbon isotope pattern in Spartina had one value, the biochemical fractions were very different—not at all what Benner had predicted. Cellulose and hemicellulose had carbon isotope patterns with slightly more ¹³C in them, while the lignin (the material that makes wood hard) isotope composition had considerably less ¹³C. Uncharacterized material, suberins and other insoluble material, had carbon isotope compositions close to those in lignin. As the relative proportion of lignin relative to other compounds increased in the litterbags from 10 to 15%, the carbon isotopes of the remaining Spartina showed small, but significant changes in the direction of what we had measured in sediments and old plant fragments. The change in carbon isotope signature demonstrated that as the plant decayed, labile celluloses were preferentially decomposed leaving more isotopically different lignin.

         Ron, Kent, and I widened the study to measure biochemical fractions from eight other species of plants (Benner et al., 1987). In all cases, the carbon isotope signatures of lignin showed that same depletion in ¹³C relative to bulk plant material. Carbon isotopes of the cellulose and hemicellulose fractions from the eight plants had similar patterns to what we measured in Spartina. This paper is my most highly cited publication. It was rejected first from the journal Science because a reviewer was not certain our results could be extrapolated to other plants and ecosystems. The work was then published in Nature and has survived the test of time. It has become a classic.

         Subsequent studies with compound specific isotope analysis of individual carbohydrates (Teece and Fogel, 2006) showed that the major 6-carbon sugars in celluloses, glucose, galactose, and mannose, have quite variable carbon isotope values. In higher plants, the synthesis of these sugars and their translocation to wood, stems or rhizome is probably associated with additional isotopic fractionation. Small carbohydrates (i.e. sugars) are the most biosynthetically-active and labile molecules in an organism and in the environment. Variation in their carbon isotope signatures compound specific level reflects this dynamic nature.

         Ron Benner and I after more than 30 years of working together on various projects are both entering the realm of planned retirement, trying to figure out how to slowly unwind and unravel ourselves from a life long career that we’ve loved. His advice to me has been to think about the new life ahead, the new positive challenges, and to embrace the good times we had during our scientific journeys.

Insights into Teamwork and Collaboration

Hans Amundson--AMASE visionary

Andrew Steele, Steelie--the Soul of AMASE

AMASE began as a small, tight-knit group of scientists, artists, and PR people from around the world. Hans Amundsen had the vision to create AMASE and managed it peacefully for many years. When we received NASA funding with Steelie as Principal Investigator, the dynamic changed. Hans became Expedition Leader, and Steelie, Chief Scientist. The management team was formed, met every year in either the US or Europe to plan the next year’s expedition. We loved each other. Steelie and Hans were like brothers. We developed Rules of the Road assuring that we were “One for all, and All for One.”

         Things changed when some groups had better success and followed through with abstracts to international conferences and drafts of manuscripts. A few of the scientists never shared their data for one reason or another. Whether this was fear of not getting funded or scooping one instrument team versus another is not clear. By 2009, the team had seemed to me to be falling apart. There were those people who were seasoned Arctic veterans and those that weren’t hardy Arctic explorers. I was never sure at this point in time where I lay. Money, and funding, press coverage, and relationships with NASA and ESA often seemed to be more important than science and collaboration. The last AMASE in which Carnegie folks participated in ended on a disappointing note. I was glad that I did not join that year.

         The strong personal bonds built in 2003 had been reduced to thin threads. Communication was strained. I felt sad to hear of the troubles between individuals and groups. This was one of my favorite endeavors of my career, some of my very favorite colleagues. We gently parted ways. Hans and Steelie entered a silent truce. NASA’s Mars Science Lab with its rover Curiosity launched and the instrument folks and engineers shifted their efforts there. Where did things go wrong?

         Hans and Steelie have strong personalities, sizeable egos, and direct visions of where they want to take their lives. Amazingly (or AMASEingly), their personalities, egos, and visions intersected for a time producing the success of AMASE. As their visions diverged, the personalities (and egos) could not sustain the collaboration. While I remain close to Steelie, often we say as science brother and sister, I am no longer in direct contact with Hans about what we discovered that still needs to be published. Nearly ten years after the last official AMASE, I recall those great moments of seeing walruses and polar bears in the wild, the thrill of fording an Arctic river, and hiking across glaciers.

         Did we accomplish what set off to do? Yes. AMASE contributed significantly to the training of scientists and engineers currently involved in active Mars science and in planning Mars 2020. Paul Mahaffey, SAM’s principal investigator, brought an international team of younger scientist with him, some of whom were very field savvy and others who had little experience picking up a sample and analyzing it. This talented group (Jen Stern, Oliver Botta, Jen Eigenbrode, Pan Conrad, Inge Los Ten Kate, Amy McAdam) cut their analytical teeth in funky labs on the R/V Lance using a primitive prototype of SAM. The experience surely has contributed to the overwhelming success of this team with its dozens of Science and Nature papers from Curiosity.

Rover Team: Ashley Stoupe, Mike Garrett, Paulo Younse, and Liane Benning, Svalbard 2007

         Although a different rover came on AMASE, the rover engineering team from JPL had to learn what their system would do under much more challenging conditions than they had previously experienced. As observers, the rest of the AMASE group watched this team struggle and overcome personal differences in style and talent. All of them continue at JPL, driving rovers on Mars. Blake’s CheMin team sashayed into Svalbard with a strong prototype and a coordinated team. They left with a stronger idea as to how their instrument could integrate with the search for life. Their work remains a cornerstone of Curiosity.

         Students were trained and postdocs tested. They learned to trust themselves in a remote, hostile environment and to get along on the tight quarters of a research vessel. I think its fair to say that they will never go on a better field expedition than AMASE in their lifetime—unless they make the trip to Mars. Further, they rubbed shoulders with the movers and shakers of astrobiology, exchanging ideas, working out problems. There is no better way to engage and retrain young scientists than a voyage like this.