Spring 2020


Marguerite Davis (foreground), Esther Lederberg (top two photos), and Elizabeth McCoy (bottom two photos) each made pivotal advances in their respective scientific fields. And each one of these women scientists has a remarkable story of persistence and discovery. Photo illustrations by Danielle Lamberson Philipp.

It took a hard-fought battle, but in 1919, after decades of petitions, demonstrations, and arrests, women finally won the right to vote.

The passage and ratification of the 19th Amendment was one of the signature accomplishments of the first half of the 20th century — an era that would see many more. Women were stepping forward to fight for inherent rights and proper recognition in a rapidly changing society. In 1916, Jeannette Rankin of Montana became the first woman elected to the U.S. House of Representatives. Amelia Earhart flew solo across the Atlantic Ocean in 1932. In 1950, Althea Gibson became the first African American to play at the U.S. National Championships tennis tournament.

Those years also brought exciting scientific discoveries and innovations— the theory of general relativity, the model of the atom, the production of insulin, the Big Bang theory, and evidence that DNA is genetic material. Most of the advances in science and technology were attributed to men, who dominated the fields at the time. But just as women were making their marks in politics, sports, aviation, and other spheres, they were also pushing to be seen and heard in a scientific world booming with discoveries — many of which did indeed come from the hands and minds of women scientists. But a number of factors in this era made it difficult for women scientists to gain the recognition they deserved, explains Nicole Nelson, assistant professor in the UW Department of Medical History and Bioethics.

“Over the course of the 19th century, science transformed from being a pastime pursued mostly by wealthy men into full-time, paid work requiring particular credentials,” Nelson says. “Even when women earned Ph.D.s, the job options for women scientists were limited. They were relegated to working in low-status, underpaid positions where they received little credit for their work. Their contributions were made invisible. It took the painstaking work of women historians to bring their stories to light.”

The setting for many of these stories is the College of Agricultural and Life Sciences (CALS). Women have been at the forefront of some of the college’s greatest advances, from the groundbreaking discovery of vitamins to a revolution in the production of penicillin. These innovations and many others — past and present, at CALS and beyond — resonated throughout the academic world and, more importantly, everyday life. And the women scientists behind them propelled the scientific community and society into a new frontier where the contributions of women are accepted, acknowledged, and appreciated.

Marguerite Davis and the Discovery of Vitamins

Look at any nutrition label in your pantry or in any supplement aisle at the grocery store, and you’ll see vitamins — bottles and bottles of them in pill and capsule form. But these compounds, commonly encountered today, were literal unknowns until Marguerite Davis took an unpaid position with biochemist Elmer McCollum. In a lab at the University of Wisconsin, the pair identified vitamins A and B and opened the door to decades of vitamin and nutrition research.

A portrait of Marguerite Davis accompanies her passport application in 1915, when she traveled to the University of Toronto for work. Photo: National Archives.

Davis was born in 1887 in Racine, Wisconsin. Her grandmother was an early champion of women’s rights, and her father was a physician and botanist. Those influences, as well as her interest in science, led her to attend the UW in 1906. In 1908, she transferred to the University of California, Berkeley, where she earned a bachelor’s degree two years later.

Davis soon returned to Madison. Her father, who had retired from medicine and moved to the city to work as a botanist, was looking for someone to care for his house. While taking care of the home, Davis looked beyond its walls to satisfy her intellectual curiosity. She found what she was yearning for in McCollum’s lab in the Department of Agricultural Chemistry (the Department of Biochemistry today). McCollum requested a salary for Davis annually, but it wasn’t granted until her sixth year in the department.

McCollum had been studying nutrition and was using “purified foods” — foods made with known amounts of protein, carbohydrates, and fat — to find optimum amounts of each component for a healthy diet. But it quickly became clear to him from experiments with cows that diet wasn’t as simple as just protein, carbs, and fats. Cases of blindness and stunted growth in cows meant something important was missing from the purified foods. After convincing other faculty members of the value of using rats as models, McCollum turned to the rodents for his research. Compared to cows, rats reproduced more quickly and ate much less. The rat experiments also supported the idea that purified diets were not enough. But what was missing?

The answer to that question could only come from time-consuming experiments. Luckily, Davis was looking for this kind of an opportunity, and McCollum brought her on board to feed the rats and take detailed notes of what she observed.

In 1912, Davis and McCollum found that milk-fed rats grew while rats fed olive oil or lard became sick and stunted. Milkfat clearly gave the rats some kind of health benefit. Next, the researchers extracted fat-soluble compounds from milk and added them to the olive oil and lard. As expected, the rats consuming the fortified oil and lard turned out as healthy as the milk-fed rodents.

Davis and McCollum’s findings were published in 1913, when listing a woman as co-author on a scientific paper was unusual — an indication of her critical contributions. They went on to call their compounds fat-soluble A. The name set their compounds apart from a different substance, described by another research team, that Davis and McCollum named water-soluble B. These sets of compounds were later renamed vitamins A and B.

To find nutrients in dairy-sourced fat was a feather in the cap for America’s Dairyland, but Davis and McCollum felt the same nutrients must also be found in other foods. After all, most animals don’t drink milk beyond infancy, but they continue to grow. The team went on to identify leafy greens as a source of the vitamins as well.

This body of work led to the discovery of other vitamins, the foods that contain them, and their role in human health and nutrition. For example, vitamin C was identified as the compound that could prevent scurvy, and vitamin B was found to be a complex of several different vitamins.

“Not only did Davis receive the acknowledgment from Dr. McCollum as being integral to the vitamin discoveries, she has also been given credit for founding the nutrition laboratories at UW–Madison,” says nutritional sciences professor Sherry Tanumihardjo. “These laboratories are still going strong in the Departments of Nutritional Sciences and Biochemistry.”

Davis also branched out internationally. A passport application from 1915 shows her seeking to travel to the University of Toronto for work and provides an interesting window into society in the early 1900s. Davis states her occupation as research assistant and describes many of her physical attributes, as required by the form, such as “Forehead: medium” and “Nose: straight.” She also struck through several lines at the beginning of the form where the applicant, assumed to be a man, is asked to include the names of his wife and children.

In 1940, after time spent at Rutgers University to develop a lab for its school of pharmacy, Davis retired and moved back to her hometown of Racine. In retirement, she was extremely active in civic affairs, and, in 1958, the Racine Women’s Civic Council recognized her for her contributions. Davis died in 1967, three days after turning 80, but her legacy lives on today, not only in every vitamin bottle but also in modern nutrition studies seeking a better understanding of health and wellness.

Elizabeth McCoy and Penicillin for the People

At some point in our lives, many of us have been prescribed penicillin. Perhaps it fought off a childhood ear infection or treated a bout of pneumonia. The drug likely saved us from health complications, and it did so without breaking the bank — thanks to Elizabeth McCoy BS’25, MS’26, PhD’29. Her work in bacteriology led to the first common — and cheap — strain of penicillin.

Elizabeth McCoy in the bacteriology lab in 1953. Original photos: University of Wisconsin–Madison Archives, Helena Lopes, Crulina 98 [CC BY-SA (]

McCoy was born in 1903 in Madison, Wisconsin. Her family owned a farm in the nearby Town of Fitchburg, recognized as the first farm in Dane County to grow tobacco. Her mother, Esther, was a nurse and passed her flair for science on to her daughter. McCoy’s love of learning drove her to finish an accelerated secondary education program. Then an early encounter with a pony steered her toward the study of bacteriology.

When McCoy was a child, a family friend and bacteriologist at UW–Madison, William Dodge Frost, drove a horse-drawn cart to visit the McCoy family. Upon trying to pet the animal, McCoy was bitten, and her arm became swollen and painful. The family physician, while scraping the wound and applying iodine, explained the details of bacterial infection to her, and her mother went on to teach her about bacteria in health and in the home.

These experiences led McCoy to study bacteriology at UW. In her senior year, she met bacteriologist (and future university president) E. B. Fred, who hired her as a research associate. McCoy took graduate courses before finishing her undergraduate degree in 1925 and went on to earn both a master’s and doctorate under Fred’s mentorship in 1926 and 1929, respectively. She joined the faculty after completing her Ph.D., and, in 1943, she became the second woman at UW, outside of home economics and nursing, to become a full professor.

As a researcher, McCoy pursued a number of interests. She became an expert on lake ecosystems and the bacteria living in them. She spent several summers at the Trout Lake Station in northern Wisconsin and later directed the bacteriology lab there. This field of research continues today at the university on the shores of Lake Mendota, often called the most studied lake in the United States. “I feel humbled and fortunate to be following in her footsteps in the Department of Bacteriology, studying the diverse microbes living in Lake Mendota and other Wisconsin lakes,” says Trina McMahon, a professor of bacteriology and civil and environmental engineering who specializes in aquatic microbial ecology.

McCoy also studied a bacterium capable of producing butyl alcohol. In 1946, she secured a patent on the process used to ferment molasses into the alcohol, and she later traveled to Puerto Rico to help establish a fermentation plant there.

One of McCoy’s most important findings came a few years earlier, during World War II. When penicillin was discovered in 1928, it was expensive and difficult to procure. During the war, the U.S. government made an effort to find new strains and mutants of the mold that produces penicillin and improve the ways in which the mold was grown. Researchers found a promising strain called NRRL-1951 on a moldy cantaloupe in Illinois, and they produced mutants by hitting the strain with X-rays. The mutants were sent to UW for screening, where they ended up under McCoy’s microscope

Following extensive study, McCoy singled out X-1612 as the best mutant for penicillin production. From that mutant, UW botanists created more mutations and eventually isolated Q-176, the most useful strain to come out of the program. That finding, along with improved growing methods, doubled the production of penicillin and lowered costs. The strains produced were given to industry so that as much penicillin as possible could be produced during the war. By the end of the war, the price of the antibiotic was less than 1% of its prewar cost.

In addition to penicillin, McCoy found another antibiotic on her lab bench when she discovered oligomycin in the 1950s. She and a graduate student isolated the compound from a fungus as part of a program to discover new antibiotics. They found that it could kill plant pathogens without hurting other useful bacteria. McCoy went on to collaborate with several colleagues across campus to determine whether oligomycin could be used to treat plant diseases, and the Pfizer company launched its own development program.

The commercial promises of oligomycin never came to fruition, though, as McCoy found that it moved poorly through plants and was harmful to seedlings. The antibiotic is still extensively used in research, however. Oligomycin can block the activity of an enzyme in cells and can be used to study how cells convert energy into fuel for chemical reactions.

“Elizabeth McCoy was a towering figure in microbiology for more than half of the 20th century,” says Jo Handelsman PhD’84, professor of plant pathology and director of the Wisconsin Institute for Discovery. “The sweeping landscape of her work — from lakes to antibiotic discovery to plant disease — is a testament to her formidable intellect and passion for all things microbiology.”

Fred fully supported and praised McCoy and her work throughout her career. McCoy said she never felt discriminated against by her colleagues. Despite the support she received from others at the university, it remains troubling that McCoy is not as well known as some of the other CALS giants who have become household names.

McCoy retired from the university in 1973 but remained an active researcher, focusing on using bacteria to treat sewage. She passed away just five years after retirement and left her family farm to the Wisconsin Alumni Research Foundation, long-lasting proof of her dedication to the university and scientific pursuits.

Esther Lederberg and the Creation of Model Organisms

If you’ve taken a college genetics course, there’s a good chance you’ve learned about bacteriophage lambda. The bacterial virus is used extensively in genetic research and has made possible a wide variety of research in bacteriophages — one of the most abundant biological entities on earth. All that knowledge and work is based on a discovery by Esther Lederberg PhD’50, a scientist who realized a multitude of breakthroughs in the world of molecular genetics.

Born Esther Zimmer in 1922 into a poor family in New York City, she worked hard in school and had a strong appetite for learning. After her grandfather tried unsuccessfully to teach Hebrew to her male cousins, Esther asked if he would teach her instead. After being granted the required permission from the male cousins, her grandfather began her lessons. Esther showed an aptitude for languages, putting her in good standing at Hunter College, which she attended on scholarship after graduating from high school at age 16. While she first intended to study French or literature, she soon decided to pursue biochemistry instead. Esther ignored instructors who told her that science was too difficult for women and that it was a field where women couldn’t succeed.

After completing her undergraduate degree in 1942, she went on to study genetics at Stanford University, where she pursued a master’s degree. She had been awarded a fellowship for her studies, but she found it wasn’t enough to live on. She worked as a teaching assistant or would earn free housing by doing her landlady’s laundry. At times, money was so tight that she would even eat the frog legs used for dissections in the lab.

Esther Lederberg in the 1950s. Photo: Esther M. Zimmer Lederberg Memorial Website.

While at Stanford, Esther met Joshua Lederberg. They married in 1945 and moved to Madison, Wisconsin. At UW, Esther earned her doctoral degree under R. A. Brink, and she and Joshua formed a strong partnership in the lab. Joshua became known for his grand ideas, and Esther became an expert in all things necessary for careful experimentation. Their work resulted in a number of exciting findings that would become the basis for genetics research. In 1956, the Society of Illinois Bacteriologists presented its Pasteur Award (named for Louis Pasteur, renowned for his discovery of the process of pasteurization) to Esther and Joshua in recognition of their contribution to microbiology. Although the award recognized them both, their partnership also meant that much of Esther’s research and discoveries remained in the shadows of the continued celebration of Joshua’s work.

In 1958, Joshua won the Nobel Prize in Physiology or Medicine for discovering that bacteria can mate and exchange genes instead of always making identical copies of themselves. While Esther made related discoveries as she and Joshua worked together, recognition of her contributions to the research that garnered the Nobel Prize was kept to a short acknowledgment during her husband’s speech, in which he said he enjoyed the companionship of many colleagues, above all his wife.

Esther and Joshua, however, did take joint credit for a technique called replica plating, which allowed researchers to move hundreds of colonies of bacteria from one plate to another instead of moving one cluster at a time, as scientists had been doing. Using this new technique, they were able to show that mutations in bacteria could pop up spontaneously — for example, even when an antibiotic treatment wasn’t pushing the bacteria to change to survive.

Another finding that falls under Esther’s impressive portfolio is bacteriophage lambda. Esther was the first person to isolate the phage, a bacterial virus that can infect E. coli. Lambda phage has since been used extensively both as a model organism and as a tool in genetics research.

“Esther’s scientific legacy is enormous. Her discovery of bacteriophage lambda set the stage for so much downstream work that you could teach an entire molecular genetics course based on the research conducted using it,” says genetics professor Nicole Perna. “Many careers of faculty here at UW–Madison and around the world were launched from studies of lambda. Even today, there is cutting-edge research using lambda phage itself. Beyond that, almost everything we know about how bacteriophages work is based on studies of lambda. And lambda is just one of many of Esther’s groundbreaking discoveries.”

The Lederbergs moved back to Stanford in 1959, when Joshua was asked to lead the genetics department. Esther was offered a position as a research associate and years later transitioned to an adjunct professorship, a job without tenure. From 1976 to 1986, she directed the Plasmid Reference Center at the Stanford School of Medicine.

By 1966, Esther and Joshua were divorced, but Esther stayed on at Stanford until she retired in 1985. In 1989, she met Matthew Simon. They shared a love of music, especially the Baroque style, and the two married in 1993. Just 13 years later, Esther passed away at age 83. Since then, Simon has maintained a memorial website to “make available to the scientific community and the public some of the accomplishments of the scientist Esther M. Lederberg.”


Although support from male colleagues played a positive role in the careers of some groundbreaking women in science, for many — those mentioned here and others too numerous to list — recognition came too little or too late (and in some cases, both). The expertise and contributions of women scientists were often downplayed to administrative or assistant roles when, in fact, they completed the bulk of the bench work as well as those other duties. As women achieve greater representation on the faculty at research institutions, they are gaining a stronger grip on their place in the research community and claiming their share of the credit deserved for important scientific findings.

“I was fortunate to have strong male mentors during my Ph.D. and postdoctoral work,” says Kate VandenBosch, dean of CALS and an accomplished plant biologist. “But women faculty in my programs at that time were few, so I looked to female colleagues elsewhere as supporters. Networks beyond one’s home institution are so important, especially when the community of women scholars is small locally. Now, as a female dean, I am glad to be able to support and encourage women faculty in their careers. I look forward to seeing the numbers of women in academic leadership positions grow, just as we have seen the number of women faculty increase.”

At UW, the proportion of female faculty members rose from 16% in 1988 to 36% in 2018. Likewise, only 9% of women held the rank of professor in 1988 compared to 30% in 2018. But there is still plenty of room for growth. While female undergraduate students in the college now outnumber male students, the number of women in faculty positions remains far from equal. As more women are hired in the future and find their way into scientific communities, they stand on the shoulders of the women who came before and fought for their place in the lab, literature, science, and society.

“This is an exciting time to be in the scientific community at UW–Madison,” says Handelsman. “The increase of women on the faculty has broadened the scientific ideas and approaches and increased the vigor and dynamism of scientific dialogue. Women’s discoveries have propelled science forward and diversified everything from lab management to the style of scientific debate. And perhaps most importantly, women faculty are here to support each other and the next generation, stemming the loss of talent from our outstanding community.”

Sidebar: Groundbreaking Women Scholars of CALS

This article was posted in Basic Science, Cover Story, Features, Health and Wellness, Spring 2020 and tagged , , , , , , , , , , , , , , , , , , , , .