Tuesday, December 10, 2019

How does a young person develop into a scientist?

My track coach, Anthony Segun Sokenu, and Marilyn, 1st Gold Medal 2008

Chapter One

         I won a gold medal in shot-put at the 2008 Maryland State Senior Olympics and qualified to participate in the National Senior Olympics held on the Stanford campus in summer 2009. My success at throwing a shot-put, something I’d never done as a youth, was based on attention to physical details required to propel a heavy metal ball as far as possible. It required mental concentration, practice, and a commitment to training for over a year. All of these requirements are needed for anyone to be a success in life, whether personally or professionally. Over the next 5 years, I wracked up a real, honest to goodness “track record” competing in local and state track and field meets in the shot-put, discus, 100 meters dash events, and football throw, an event sponsored by the DC Senior Olympics. I earned Gold and Silver Medals in each event, not always because I excelled necessarily, but because I showed up early on a Sunday morning, while other women of my age class slept in.

         Today, as I write the story of my life, I’m sitting at a desk in the corner of my renovated bedroom in Mariposa, California, in what will be my final office space. I look out on the California foothills, the Guadalupe Mountains in the distance, quail and acorn woodpeckers flying between towering blue and valley oaks. I’m now largely restricted to mental exercises, as my body slowly shuts its voluntary muscles down owing to the silent ravages of ALS (Lou Gehrig’s disease). In this year I have embarked on this new journey, it seemed the right time to write about the remarkable life I’ve lived through an era that has seen the rise of women as respected scientists and the start of a new field in earth science---biogeochemistry.

            A person’s personal life has its own voyage, not necessarily mirrored by one’s career. In my case, I can’t separate the two. Experiences in both spheres have shaped me as a person. Is it possible to be a 1st class scientist, mother and wife at the same time? Lynn Margulis, a noted and controversial evolutionary biologist, once said this is impossible. I am not sure what 1st class really means in either context, but I think it’s possible for women to achieve success as scientists, wives, and mothers at the same time. Learning to live with small imperfections is key. Finishing what you start is critical. Laughing at your self is necessary. Taking a stand and doing what is “right” can help you sleep at night when unfinished business, housework, and relationships internally nag at 3:00 in the morning. Keeping an eye on the long run, not short term setbacks. I believe I succeeded at all three; what I’ve done has been good enough, and just recently has been judged by others to be 1st class. That’s not as important, however, as how I judge myself. To be comfortable in your own skin, to know what makes you happy, and to allow yourself to be what you want to be is as important to me as “1st class.” Rewards come at odd times. My children talk about cool adventures, my husband and I continue to enjoy life ALS not withstanding, and I’ve had a whale of a good time with colleagues young and old.

Isotopes are invisible—why have I bothered?
            Most people work with things they can see. Doctors deal with patients, real humans. Even if they are trying to figure out a disease, they can look at blood and tissues, listen to organ systems working away. Most ecologists deal with plants, animals, or soils that they can hold or observe, count with their eyes, or manipulate. Even chemists can carry out reactions with liquids, solids, and gases and create products that can be seen, smelled, and weighed. Engineers create tangible things—cars, computers, and bridges. Non-scientists sell things, nurse people back to health, teach students, or manage money.
            I’ve spent over 40 years working with something that I can’t see, hear, smell, or taste—studying the stable isotope, which can only be studied through a complicated series of chemical and physical steps that result in a very small electric charge being turned into a computer signal. The work is abstract. It’s picky. I have to be satisfied with looking at a computer screen or a spreadsheet to get my work’s reward.

            Why in the world would anyone spend four decades in such a pursuit? Because those small differences in the types of isotopes—carbon, nitrogen, oxygen, hydrogen, and sulfur—can tell those who have studied them how animals and plants have survived over billions of years. We can understand chemical reactions that can’t be seen, but are vital for living organisms to function. We can tell the types of foods you’ve been eating. We can figure out where you were born and where you moved during your childhood years.

            My expertise did not come suddenly, and it wasn’t learned from a book. When I was a graduate student, I knew nothing. We had to memorize how a mass spectrometer—the instrument we use for our measurements—worked, but had no real understanding. As a postdoc, I made many mistakes in the laboratory. Broke a lot of glass lines, blew up a few things. I learned from those mistakes, but truly, couldn’t work my way out of any complicated situation. What I did learn during this time was how to interpret the “magic numbers” that were calculated after all the chemistry and physics was done right. I figured out something about the biology of the organisms I was working on. The magic numbers were no longer “magic”—they were real.

            As a new staff member building my own lab, I built up my experience by learning new things every year or so. Many scientists spend their whole lives researching one slim topic. I branched out quite early, which was key for developing a broad sense about invisible isotopes and what they mean. Today, I can trouble shoot an instrument from my desk in Mariposa, talking to students and postdocs via Skype. None of us see the isotopes, but we measure times, temperatures, flow rates, and peak sizes. They are learning the nuts and bolts of their chosen field.

            We analyze substances referred to as isotope standards. There are internationally recognized isotope standards, commercial isotope standards, inter-laboratory isotope standards, and individual laboratory isotope standards. These substances range from toilet seats, peach leaves, plastic, oil, amino acids, milk protein, water, gases, hair, feathers, fertilizers, extinct fossil shells to meteorites. Some believe that if you are going to analyze animal tissue (e.g., squirrel monkeys), you need to have a squirrel monkey standard. Every time we isotope geochemists measure one sample, we analyze 3-4 standards of different types to compare it to.

            For a first pass, our standards need to provide the correct “magic number” or else something is wrong. One of the chemical steps might need adjustment. There might be a vacuum leak. An electrical wire might be loose. If the numbers do come out matching what others have measured, we then look to see if they are reproducible. The laws of chemistry and physics are the same in Riverside, California, as they are in Beijing, China. If we can make a measurement in August, we should be able to repeat it in December. To make accurate and precise and reproducible measurements of small, sub-microscopic particles demand that attention be paid to the smallest details.

            What sort of person takes up this type of science? Starting in the 1960s, only a handful—literally—was interested and involved in the field. When I started in the 1970s, everyone personally knew almost everyone in the field. We read just about every paper published with stable isotopes. Now, there are several thousand scientists interpreting these “magic numbers,” to figure out topics as widely ranging as how the Moon was formed, learning about processes on distant planets, and finding out if Tour d’France bike racers used illicit performance enhancing drugs.

            We’re a fairly tight knit group in some ways. I correspond with about 100 different people a week on the small details of stable isotope analyses. We criticize each other’s work, usually supportively. Many of us meet once or twice yearly in person, where we present our findings for critical review.

            The hazards in this field are numerous. We depend on explosive chemicals—fluorine gas, for example. We generate poisonous gases—carbon monoxide, for example. We use deadly chemicals—hot mercury and hot uranium. I’ve been burned, shocked, hit with flying glass shards. Some of my colleagues have suffered much worse. With only a very few exceptions, isotope scientists are careful people. We work well with details.

            Now, when I see a landscape or learn about a new animal, I think, “How would stable isotopes help figure how these things work?” It might be surprising to some that I could spend such a long time devoted to things I can’t see, smell, taste or hear. But, to others, not surprising at all.  We’re isotope nerds.
Dominic Papineau, Marilyn, Seth Newsome, Geophysical Lab 2009

A. What is an isotope?
            An isotope is a variation of a basic element. This means that atoms can have different “flavors.” Isotope “flavors” of the same chemical element always have the same number of protons (atomic number), but different number of neutrons. For example, one of the most common elements is carbon. Three isotopes of carbon are carbon-12, carbon-13, and carbon-14. The number after carbon represents the mass of each isotope respectively. Each of these isotopes has 6 protons, therefore an atomic number of 6. To determine the number of neutrons just subtract the atomic number from each mass.
            We call carbon-13 the heavy isotope and carbon-12 the light isotope. “Lighter” isotopes can run faster through chemical reactions and “heavier” ones lag behind. Because the different isotopes move at different speeds through plants and animals, the amounts of light and heavy isotopes can change. For instance, plants use carbon dioxide in photosynthesis. The plant will use carbon dioxide with carbon-12 faster than it will use carbon-13. Therefore, leaves in plants have less carbon-13 in them, than in the carbon dioxide. The difference in the isotope concentrations between two pools of carbon, for example leaves and air, is called isotope fractionation.
Penn State Years

         The origin of life on Earth holds many mysteries for scientists of all disciplines. In the 1960s, professors and students at Harvard published papers describing their findings of trace fossils from early microbes in some of the Earth’s oldest Precambrian rocks, 1 to 4 billion years old. At the time, the biological revolution was still a decade away. In earth science, plate tectonics did not yet provide the framework for interpreting how continents were built or how their sedimentary features had been formed. Dating of rocks was just being developed, and many of the Precambrian deposits studied at this time for the presence of fossils had just been dated. A key publication for me as a biology major at Penn State University was a review in Scientific American by Elso S. Barghoorn, Harvard professor and paleontologist (Barghoorn, 1971). Along with his student William Schopf, the two published photographs of thin sections and electron micrographs of putative microbial cells (Schopf and Barghoorn, 1967).

         Barghoorn noted that life had to conquer three different thresholds to evolve to where it is today. From the chemical soup of the early Earth, organisms needed to develop biosynthetic pathways such as photosynthesis. He presumed that the first organisms were heterotrophs, feeding on compounds in the chemical soup. Barghoorn argued that autotrophy—making biomass like plants do today-- was also needed to continue the supply of organic nutrients for heterotrophs. The second threshold was diversification, in order for single-celled organisms to develop into more complex forms, including chains of cells or stromatolites, macro structures seen in sediments over the years.

         The third threshold that organisms needed to transcend was the formation of cellular microstructures, notably the nucleus, in order to become multicellular organisms. Sedimentary deposits from three different continents, Africa, Australia, and North America confirmed to Barghoorn, Schopf and others that life was widespread on the earth during its first 2 billion years and had originated in similar fashion across the planet.

         The conclusion that these were fossil microbes (Schopf and Barghoorn, 1967) started a four-decade debate about the biogenicity of these structures found in ancient rocks. The authors noted that although it is difficult, I would say impossible, to relate the potentially biological structures to intact cells, they concluded that the spheroids are “almost certainly of biological origin” representing cells, most likely algae. Electron microscopy of ancient sediments was a new technique at the time. Microscopic examination coupled with chemical and isotopic analyses seemed to prove the interpretation that these were fossil organisms. Their paper certainly caught my eye and my interests because it combined new chemical instrumentation to describe once-living organisms in a geological context. These three fields of science--biology, chemistry, and earth science--rolled into one sparked my career.

         At Penn State, two experiences largely determined my interest in these fields: a 3-month Marine Science quarter at Wallops Island, Virginia, and a special class in Geochemistry. Both of these opportunities were sparked by my friend Nancy “Natasha” Peters. “Natasha” and I met first quarter in summer 1970 when we lived on the third floor of Curtin Hall. We were both out of state students, thrust into the rural atmosphere of State College—she from the DC area, me the Philadelphia suburbs. That summer we were introduced to a group of renegade fraternity guys who inducted us into their frat with a ceremony complete with robes, candles, and the secret handshake. After that experience, we were partners in adventure for the next three years. Natasha was a biochemistry major, aced all her exams, but wasn’t bitten by the same science bug that I was, but nonetheless dug up these interesting courses. She heard about the marine science program and wrangled us, just technically juniors, into a competitive list of students chosen to participate.

         Wallops Island Station is a former Navy base on the coast of southern Virginia. It also served then and now as an outpost for NASA satellite tracking and small rocket launches. In March 1972, forty Penn State students led by Professor Albert Guber from the Earth Science Department moved into former Naval officer quarters on the outskirts of the base. There were only 4 women in the group---Nat, Nancy Zeller, and me, all long time friends, and one other. As students in the first class to start this program, we were pioneers. The quarter was broken into three segments in which we concentrated on subjects—Physical Oceanography, Marine Biology, and Geological Oceanography. It was heaven on earth for me as a student. Our studies consisted of evening lectures with day times spent in the field in the neighboring environments of Chincoteague and Assateague Islands and beaches. Weekly we went out on small boats in the bays and offshore collecting sediments, water samples, and marine organisms that we kept alive in tanks in our lab.

         Nancy Zeller, Nat, and I pitched in our meager resources and with the help of Nancy’s dad purchased a small skiff with an outboard motor that we moored under a bridge on the road to Chincoteague. The inlet opened up to miles of pristine salt marsh with its green Spartina grasses, oyster beds, and tidal flats beckoning us to investigate their mysteries first hand. When we had a slow day, we got in that little boat in early morning, making temperature and salinity measurements, digging up clams that we cooked for dinner, and just plain immersing ourselves in the environment. Years later this experience influenced my choice of research projects. I was now thoroughly hooked and prepared to do whatever was necessary to make marine science a career. 

         A year later in spring 1973, Nat rushed into my dorm room and said, “Mar! You’ve got to signup for this class--Organic Geochemistry. The professor is this older British man and the class has only 5 students in it, most of them grad students. The only problem is the class meets at 8 am.” Ugh, I thought. I was in my 4th quarter of required physical education classes and had signed up for bowling Monday, Wednesday, and Friday at 8 am, same time as the Geochemistry class. I went to meet with the professor Dr. Peter H. Given in his office, which contained the requisite piles of correspondence, journal articles, and unfinished business that usually graced professors’ desks. Given dressed formally in coat and tie, albeit on the rumpled side, sported a full white beard, and a robust frame. Turns out, he despised early morning classes and readily came up with the idea of changing the time of the class to later in the day. He managed to change two of the three classes, but I needed to tell my bowling instructor that I needed to miss one class per week. I was a pretty decent bowler with an average of 150 points per game, having spent my Saturdays as a youth on a bowling team in South Jersey. Reluctantly, I was given permission to miss a class, but my grade dropped to a “B,” nothing compared to the life-changing class I took with Dr. Given.

         We learned about petroleum and coal formation, how living organisms decayed and entered the fossil record, and about the origin of life on Earth. The research on Earth’s earliest life was all very exciting for me. Given revealed a set of fascinating papers to our small group of undergraduate and graduate students. I was immediately hooked! As a biology major, I wanted to know how to identify chert, the rock type where fossils were found. I wanted to use my fascination with biochemistry to find molecular fossils. Last but not least, ironically at the time, I was not at all interested in the carbon isotope papers published by Tom Hoering (1963; 1967) and others. Little did I realize then that carbon isotopes and the process of isotope patterning by blue-green algae (cyanobacteria) would come to occupy the majority of my research career.        

         Prof. Given’s class was a huge eye opener for me in many ways. I was able to use my knowledge and love of chemistry to begin to understand biological, environmental, and ecological processes. In the 1960s, scientists at the Carnegie Institution led by Philip Abelson, Tom Hoering, and P. Edgar Hare were discovering simple molecules like fatty acids in marine sediments and fossil shells (Abelson et al. 1956; Hare and Abelson, 1968). Then postdoctoral fellow Patrick Parker published a landmark paper (Parker, 1964) in which he not only described the molecular distributions of fatty acids in marine organisms, but isolated these molecules to measure their carbon isotope patterns. Parker and colleagues at the University of Texas Marine Science Institute (UTMSI) were publishing papers at a rate of one a year in the journal Science on new compounds found in sediments, marine ecosystems, and blue-green algae.

         At the conclusion of my undergraduate years as a biology major, I was convinced that I wanted to combine biology, chemistry, and geology in an interdisciplinary career. Professor Given helped tremendously by suggesting two United States labs and one British group, that were engaged in the research I was most interested in. I chose to attend the University of Texas Marine Science Institute (UMTSI) in Port Aransas based on a welcoming phone call from Professor Patrick L. Parker. Pat Parker provided a positive response to my potential and offered me a position as a graduate student in an interdisciplinary course of study under the joint supervision of Parker (a marine organic geochemist), Chase Van Baalen (an algal physiologist and specialist in cyanobacteria), and Bill Behrens (a marine geologist). I accepted the position and in January 1974 I headed south to Port Aransas, Texas, on the coast of the Gulf of Mexico. In hindsight, my decision to study at UTMSI with Parker was without question the right choice. Parker’s research on the relationship of modern organisms to the compounds found in Recent sediments, as well as his interest in carbon isotopes, set the path for my career in biogeochemistry.
Brother Fred, Marilyn, sister Barbie, dad Art Fogel, college years, circa 1973

Standing out as a woman scientist

         When I first started my career as a young undergraduate at Penn State, we all took a test that would help us determine what we might be interested in and suited for in terms of a career. Recently, I unearthed the old results of that test taken nearly fifty years ago in 1970. Options for careers for women at that time--college educated women--included nun, secretary, and sewing machine operator, among other women-only type careers. My results indicated a suitability for Chemist, Entertainer, and Naval Officer. One of them was spot on; the other two describe me in some sense. As a leader of a scientific laboratory for 40 years, you’ve got to have some “military officer” personality to succeed. As a college professor for the past 6 years, I’ve also had to be an Entertainer on occasion.
         In 1970, there were quotas for how many men could be accepted to universities and colleges vs. how many women. Most of the “top” universities were just starting to accept female undergrads.  1969 was the watershed year for high-ranking places like Yale and Princeton to decide to accept women for the first time.  At Penn State, the ratio of men to women was 3:1; at Cornell University where I also applied, the ratio was 8:1. A male student from my high school with nearly identical test scores and grades was accepted to Cornell, but my woman friend and I were not. Luckily, I was accepted at Penn State; competition for women to get accepted to first-rate school was intense, probably because of the quotas. Owing to the fact that I was from out of state (New Jersey), I needed to start classes in the summer. At that time, we sensed the discrimination based on quotas was unfair, but no one did anything about that. In my science classes, there were about 20-30% women in biology, fewer in chemistry, geology, and physics classes. As a youngster, having more young men around than young women was fine with me.
         During my high school and undergraduate years, I worked at many low-level jobs that helped reinforce my determination to build a more interesting life in science. Starting with babysitting in junior high school, a short run as a Howard Johnson’s waitress, I spent summers as a chambermaid in a hotel at the Jersey Shore and as a gardener and maid in Santa Barbara, California. I much preferred the quiet life of the maid or gardener rather than the time sensitive, outgoing requirements of a waitress. In my senior year of college, friends helped me get a coveted position as a Peanut Saleswoman at Penn State football games. This might sound like a menial job but it had great benefits---I could sell my football ticket and make ten bucks! Peanuts cost 40 cents, but if you went into the alumni stands, more often than not you got a whole dollar and “keep the change.” In the student sections, guys offered you a drink of whiskey from a flask they’d smuggled in. You could sit at the 50-yard line in the stadium if you needed a break. My parents came up for one of the games, but they were embarrassed that their daughter had to sell peanuts instead of dressing up and going to the game with a date, which was not my style. After that game, they upped my weekly allowance from $10 to $20, which I used for all of my food, entertainment, and incidentals.
         Working for bosses who were disorganized or even mean was a good learning experience. Showing up for work on time and prepared at an early age is a skill never to be forgotten. Today as I teach undergraduates at the University of California, I encourage them to sample as broadly as possible the jobs people have that fall far below students’ expectations. Working with people from all different walks of life provides education far beyond what is learned in school.

Rounding Third Base and Heading Home

Cards from Franny and Flowers the Rumbles   My daughter Dana is marrying George Goryan on June 25 at our home in Mariposa...