I grew up straddling worlds. I was born and raised in Warwick, RI, a couple miles from Providence. My mom was also born in Warwick, RI, but my dad was born about 3700 miles away in Lima, Peru.
My dad, Hugo Evaristo Díaz Mendizábal, was the second oldest of nine children. He would tell a story about one day when they had no money to buy food and his mom went to the butcher. She placed a stack of butcher paper on the scale and demanded that she was owed that much meat over the years of buying from the butcher’s store—and it worked. This story is indicative of the strong Mendizábal women, and also of the reasons that my father immigrated to the U.S. in 1960. As the second oldest, he and his older brother were the first two children to immigrate to the United States after his dad, a surveyor, immigrated and then promised them jobs with him. At fifteen years old, after completing his cartography certification at the Instituto Geográphica Nacional and speaking little English, he arrived in California—to a broken promise and no job.
My mom came from a working-class, New England Protestant family. My grandfather worked his way up to a foreman in a machine shop, and my grandmother was a homemaker. They built the house they lived in—living in the basement until the first floor was complete and so forth. They both survived the Depression, which forever left an impression on their lives. My grandfather enrolled in the Civilian Conservation Corps, a federal work program initiated by Roosevelt. They had an urban homesteader garden before it was trendy and when it was necessary. My grandmother could make dinner out of any scraps and passed her knowledge of pie making and preserve making to me.
My dad’s employment prospects brought him eventually to the east coast. It was in Rhode Island in 1966 when he met my mom, on an invitation from his Filipino coworker to dinner at his wife’s house. My mom, Becky Ober, was the wife’s younger sister. In 1967, my mom graduated high school, married my dad, and was pregnant with their first child.
I think I was aware of how unlikely my parents’ (and my aunt’s) marriage was. I was raised in my mother’s church, but my dad went to a Spanish-speaking Catholic church in Providence. But naively, I never linked these to race or ethnicity. It wasn’t until years later, as I was watching Guess Who’s Coming to Dinner? with Sidney Poitier when I understood the world in 1967. It wasn’t until 1967 that the Supreme Court overturned the “miscegenation laws’’ prohibiting interracial marriage, as unconstitutional.
My parents raised my older sister, Alisa, in Rhode Island for only a short time before moving to southern California, to where the rest of my father’s family had now immigrated. It was in California where my older brother, Devon, was born. My dad was able to find work during the day, live in UCLA family housing, and attend night school in the evening, working on his degree in computer science. By this time, he realized that maps were going digital or perhaps more broadly foresaw the future of computing—nearly all of his siblings pursued degrees in math and computer science after coming to the U.S.
Living in Los Angeles in the late 1960s as a Latinx family was a very different experience than what I was raised with by the time my parents had me. When Alisa was enrolled in school, due to her dark complexion, she was automatically placed in a Spanish-speaking classroom. In this age of assimilation, she had been raised as English-speaking only, leaving her crying when she got home from her first day of school. My dad recalls that he would have to carry a copy of his class schedule in his pocket because on his way to night-class he would be routinely pulled over by cops who wouldn’t believe he was on his way to class. They lived in California only a few years before returning east.
I was raised in a different America—one nearly 15 years later, on the other side of the United States from my Latinx familia. One where my dad finally finished his computer science degree after 18 years of night-school and transferring colleges. One where my mom also went back to college to transform from a 1980s secretary to a school-based speech-language pathologist. One where I was raised in an English-speaking home but took Spanish-classes to be more connected to my Latinx roots. One where I proudly brought my dad’s Peruvian trinkets to class for show and tell. One where this Latinx family had now achieved something akin to the American Dream (as long as you don’t count the years of school debt, the clash of family backgrounds, and the lack of wealth-building). One where many of my Peruvian aunts and uncles had been successfully educated and employed in the burgeoning computer science industry.
In an article I co-authored with my mathematician cousin, Marizza Bailey, called “Revealing Luz’’, I wrote about my journey both towards and away from mathematics.  “Revealing Luz’’ was about my great aunt, Tía Luz, who my dad knew growing up in Peru. She was a math teacher and inspired many school children and family members. The greatest gift she gave me was that my dad grew up knowing that the women in his family had the potential to be incredible mathematicians and educators. As I balanced this line of being Latinx-identified, but separated from most of them on the opposite coast, most of my connection to my mathematical and computational successes as well as my Latinx heritage was through my dad. My dad often spent our time together working on math workbooks while my younger sister, Naomi, was in dance class. My older siblings would show me math flashcards as a baby, however, one could argue an even earlier influence—I am a part of mi tía and she is a part of me, and math is a part of both of us. This is a concept Rochelle Gutiérrez brings back to us from Mayan philosophy called In Lak’ech in which we see ourselves in others.  The version Dr. Gutiérrez introduces in “Living Mathematx” is more an acknowledgement of a broader community interconnectedness and perhaps less literal than what I mean. No matter the reason, my identity as a mathematician is thoroughly wrapped up in my identity as a Peruvian-American.
My dad, ever the influence on my mathematical opportunities, chose a town to move to when he relocated to Boston that had an excellent math program. I captained a math team at a public school with a multi-year winning record in Massachusetts and New England. I was also part of the American Regions Mathematics League Massachusetts A team that won in 1998. I would guess others considered me very successful in mathematics, but I always thought of myself as a modest performer among the best. I clearly loved calculating, but had no interest in studying proof-based mathematics in college. All of my siblings solved this by pursuing degrees in civil engineering, but I wanted to go save the oceans and the rainforest. I did not understand what math could offer me other than a job teaching (which I have to say I loved doing, as by this point I had been tutoring math for years. But I did not love this as much as saving the planet!). My rebellious choice as a headstrong teenager was to reject math, and also reject the thought of applying to any college without a zoology program. My second rebellion was to reject the idea of an Ivy League education—in part because I was turned off by the pomp and circumstance, but also because I did not understand that the price tag was just a suggestion. I was worried about the cost and didn’t want my dad to spend the money. At that time, I didn’t realize places like MIT have substantial money for financial aid.
I found my way back to math because I found my way into a community of mathematicians. In retrospect, I had always been looking for my community. Throughout all of my schooling, I felt I never quite fit in and had longed to be in college. When the University of Maine offered me a full scholarship, I found that community and underwent something akin to a metamorphosis. I became involved with various “diversity’’ groups and found the Latinx and Spanish clubs welcoming of my white face and school-learned Spanish. I credit UMaine, under Dr. Angel Laredo’s leadership as Dean of Students, with the intentional development and support of these communities—from its new inclusivity programming to its student leadership programs. I will always remember at our first Latinx festival and dance at UMaine, Dean Laredo gave an opening talk and said that it was las ganas (the desire), that drove us to be the best. I also found community in the mathematics department, in the math club, and in my small math classes—unlike my large biology lectures. Within these communities, I found my voice as a leader, and then I found my way back to mathematics. For many, finding math is the difficult part, but for me, it was finding my way back to math since it was a part of me from the beginning, or as we said in “Revealing Luz,” finding something that was “always-already-there.”
During the summers in college, I worked for a temp agency in Boston. I was placed at MIT in Cambridge and for two summers, worked in the basement of Building 11 as a copy assistant. I had wonderful and funny coworkers and enjoyed it immensely. We were responsible for all of the copying and computer rental time for the math department, and I found myself longingly flipping through past Putnam exams and math course textbooks. There is an odd sort of message looking back on this now—that the Latina in Building 11 was only good enough to make the photocopies. My dad, perhaps seeing this longing and realizing that I was leaning to switch to mathematics, called the MIT admissions office and made an interview appointment for transfer. What my dad did not see was the ragged students copying their thesis who hadn’t showered in many days, the campus reports of suicide, and the fact that I felt more at home among the copy staff than the faculty. I also felt more at home among my newly found University of Maine community and family, and I did not want to leave them. Ultimately worried about how I was going to afford tuition and in the midst of developing a community at UMaine, I declined MIT’s offer to transfer.
At the beginning of my third year, a few changes began to solidify my new path. I was invited to join a research group and graduate topology course by a professor, Dr. Bob Franzosa. I started dating my best friend, Scott Eaton, and by my senior year, we married. The math department hired a mathematical biologist, Dr. Sharon Crook, who combined both my interests into a single discipline. Finally, the department introduced an interdisciplinary master’s in mathematics. Dr. Crook offered me the opportunity to stay as a graduate research assistant in computational neuroscience, which conveniently solved my new two-body problem. It also gave me the opportunity to move in with my grandparents to help as they aged, despite the long commute. Sadly, in the first semester of my master’s program, my grandfather passed away, but we were grateful to be there for my grandmother.
While at UMaine, I continued to take biology courses and became particularly interested in a specific area of mathematical biology called evolutionary theory. At the time, my cousin Marizza was a PhD student in Galois theory. This gave me some confidence to pursue a PhD in order to stay in Maine as a full-time faculty member. This was a difficult leap because, in order to get a PhD in mathematics, I would have to leave Maine. Fortunately, my husband and I were accepted into all of our graduate programs, with generous assistantships and fellowships. We picked the University of Tennessee because it was relatively close, affordable, and offered the same level of interdisciplinarity I currently enjoyed while training in a rather unique area of study.
Balancing family, identity, and a PhD in math was not an easy road. As I once described it, it continued to be like the TV show Ninja Warrior—trying to navigate both the planned obstacles while dodging all the surprise ones. I had no idea really about how I was supposed to study for my first prelim at the end of the summer. Even though I excelled in class, I felt like I barely passed the prelim. The final exam for my second prelim class was held on the “Day without Immigrants.”  I was distracted the whole time thinking about how I felt I could not boycott my exam that day in solidarity. What gave me joy in these hard times was my work mentoring graduate students. I had begun calling for a teaching assistant support program after completing my exams. My proposal to the department was approved, and the next fall I began co-directing the math department’s first TA teaching development and mentoring program.
Two weeks before my orals to advance to candidacy and eight and a half months pregnant, my car was hit broadside by a tractor-trailer. I had to be induced and had my son, Gabriel, on July 25th. Then the childcare facility I had reserved space in closed without notice, and I could only find care two days a week. When my son was two and a half weeks old, I was back at the university teaching the TA development class. I called my parents to come help until daycare could start and a fellow graduate student, Erin Bodine, would watch Gabriel while I was in class. When he was not quite two months old, I passed my oral exams, wading through the fog of sleepless nights as a new mom. I was nursing him when I turned down the opportunity to attend an evening awards banquet—where, I later found out, I had been awarded the University’s Chancellor Award for graduate teaching.
Nearly five years into my PhD, my husband received a job offer for an instructor position back in Maine. By this time my parents had divorced, remarried, and retired to Maine, and my husband’s family also lived in Maine. Much to the surprise of my advisor, I decided to take a leave from my PhD ABD (all but dissertation) to be closer to family support. We moved back in with my grandmother, who by then was no longer grieving, but needed more assistance at home. I nearly quit my entire PhD as I realized I was pregnant with my daughter, Yudani. It had always been good enough to stay here with my family and teach at a local college. However, part of this dream scattered when I realized that the adjunct pay I was earning and my husband’s instructor position were not going to be enough to make ends meet. I also felt a sense of regret at the thought of never finishing the last chapter of my dissertation. So, with some babysitting provided by my retired parents, I finished as much as I could on my dissertation independently before my daughter was born, and went on the job market for a full-time position. As a math biologist in the 2000s, I was lucky to have many interviews in Maine, and I accepted an Assistant Professor position at a small environmental college, Unity College—teaching math to save the environment. It was that position, contingent on finishing my PhD before my first contract review—and the encouragement of my peers—that gave me the last push I needed to finish off the final chapter, which in retrospect was my most independent and intellectually creative work.
Moving home meant my family had more support, and it turned out to be fortuitous timing. My dad was diagnosed with a muscle degeneration disease. My mom was in a severe motorcycle accident just a few weeks before my final dissertation defense and nearly died. She was air-lifted to the hospital I lived only a few miles from, and I was there to support her and her husband as the decision was made to amputate her leg. I went to a conference only a week later, having organized sessions. I have a vivid memory of my advisor asking me if I was ready for my defense, and trying to tell him about my mom while crying on the escalator. My house in those times was a host for all of my family who came to visit my mom in the hospital. In the end, I passed all those exams and all the trials and defenses. It would be years later that I would find out I was the first Latina to graduate with a mathematics PhD from the University of Tennessee. It was an accomplishment of both grit and luck, but not particularly graceful.
Sometimes I feel conflict about the decisions I made on my path. I frequently rejected “superior’’ choices of institutional name to stay closer to my values in both family and mathematics. However, I do not think I sacrificed any education—maybe connections and access, now that I see the view from Bates, the elite small private college where I currently teach. Perhaps if I did not center family, I would not have faced the roadblocks of being a mother in academia or burdened a significant care-taking role for my parents and grandparents when they needed me. But I know also that if I had made different choices, I would not have been the same person, embraced by my communities, and given the opportunity to lead. I cannot imagine who I would have become had I not made my decisions based on the values that I held dear. I have found this true also for the students I have taught along the way, which have always held the same hidden potential, no matter where they have attended school. My advice for those on the path of self-discovery is to be true to yourself. My advice for everyone else is to look beyond the labels of worthiness that mathematicians use to judge others.
Interdisciplinarity Means Working Together
Although I describe my upbringing as fundamentally different than my siblings, I was also largely naive and shielded. I still had struggles navigating the differences between my mother’s and father’s side. We interacted a lot with the Latinx community through my father’s church, as my father would often help with translation needs. I have a vivid memory of having a newly arrived refugee come to the house with his daughter. I played with the daughter, while my dad helped the father. Later I asked him about the father because I had heard him crying with my dad. His wife had been shot at the border. Years later, in my suburban English class, I would write about this experience. My teacher scoffed that I most certainly had to be exaggerating. These many differences between worlds also played a huge role in my parents’ divorce. My dad could never shake the feeling that he was always trying to prove he was more than the Latino boy that got my teenage mother pregnant.
There were many worlds my family upbringing straddled—Catholic and Protestant, conservative and liberal, white and Brown, English and Spanish. I only added to these diverse experiences when I moved between mathematics and biology and became a northerner in Tennessee. In addition, I had to navigate these multiple worlds as a mother, as an underrepresented minority in STEM, as a woman, and as a queer individual. These many intersections, worlds, and bridges, created a confluence of experiences by which I became a leader as a boundary spanner. I was used to translating experiences between worlds. I understood the values and axioms that made these worlds operate, and I was consistently looking for common ground between frameworks and ways of seeing the worlds. I was used to thinking about language as reflecting culture and history. Other researchers in Chicana studies and education call this Nepantla—the space between these spaces which allows us to think differently and open new spaces of being.  Therefore, interdisciplinary research for me is an outlet by which I can use the sum of my knowledge and experience, but also I have found my type of boundary spanning is needed to move research and education forward.
Now I am almost used to moving between disciplines and moving between or embracing multiple identities. This perspective has been particularly important as I have started to work in building an interdisciplinary and inclusive STEM education. How do we talk to biology students about mathematical concepts? What does math feel like to others when it is spoken without first understanding their own cultures and conceptualizations of mathematics? It turns out that biology students already know a lot about math and modeling, they just understand it differently—the engineering examples of calculus speak a different language than what biology students understand. Community co-evolution has also become an important and reoccurring theme. My research in evolutionary theory led me to study plant-pollinator networks—species that work together to build diverse and resilient communities. That final chapter of my dissertation that was almost never written because I left Tennessee ABD was about how mutualistic communities co-evolve together, the structure of those networks, and why they are both diverse and resilient.  I want the STEM disciplines to build a diverse, resilient community together.
Networks for Change
Re-conceptualizing my research strengths as synthesizing frameworks and as about cultivating diverse, resilient, co-evolving community networks has given a coherency to my research program that others’ used to label “too-broad’’ or “scattered.’’ In retrospect, I always naturally gravitated to forming community support networks in my early leadership days at UMaine and with the TA support program at UT even when that work seemed separate from my research.
As soon as the ink was dry on my PhD, I wrote my first grant, to support a network called QUBES (Quantitative Undergraduate Biology Education and Synthesis). We had a dream that we would help others find high-quality curriculum materials in math and biology by collaborating broadly with professional societies across disciplinary boundaries and by providing a robust cyberinfrastructure. [6,7] Seven years and about $4 million later, we have moved far beyond our original dreams. I have also been involved in a number of other networks, all with the goal of bringing groups together to collaborate, and more recently with an emphasis on equity and social justice.
I have also been avidly involved with institutional governance and professional societies, which I enjoy. I am not sure how I started, but I have always tried to be a reliable and hard worker and say no when I cannot deliver, and so my name seems to continue to be recommended. I have served as Chair of the Education Subgroup of the Society for Mathematical Biology. I also served on the Board of BioSIGMAA, the Special Interest Group of the Mathematical Association of America (MAA) devoted to undergraduate education in mathematical and computational biology. I am currently the Chair for the MAA’s Committee on Minority Participation in Mathematics. I have served on the Editorial Board of Letters in Mathematics and currently serve on the Editorial Boards of CourseSource and Problems, Resources, and Issues in Mathematics Undergraduate Studies. In 2020, I was awarded the Society for Mathematical Biology’s John Jungck Prize for Excellence in Education.
In all of my experiences, my biggest joys have come from raising a wonderful family and from supporting others to be successful on their own terms. I remember being told as a new person in a new institution, that the ideas I had were not going to work. Even though I have seen many ideas rise and fail, I myself have seeded improbable ideas that radically succeeded. Instead of crushing potential, my goal is to always bring out the strengths of the people I work with. The next generation of mathematicians and biologists seems to be more insightful and creative than I have been, and I actively work against the institutionalized ideas that older means wiser, that collaboration means a lack of self-sufficiency, and that niceness fixes systemic inequality. There is still work to do, but I believe we can do it together.
I conclude with some advice that I have learned through experience in my life and career. I share it with the hope that it helps readers who are exploring mathematics as a career as well as those who have already found their way to mathematics and have embraced it.
- I think math is a part of us and we are a part of math, but some of us find ourselves on a lifelong entangled path with it. Follow both your heart and your brain. My brain made me pick math over biology as a primary discipline, but my heart brought me to the work I do today.
- Find your support system at school and outside of school, and use it. Figure out what keeps your brain and your heart motivated and use that to keep you going through challenges.
- My advice for those on the path of self-discovery is to be true to yourself. My advice for everyone else is to look beyond the labels of worthiness that mathematicians use to judge others.
- Actively work against the institutionalized ideas that older means wiser, that collaboration means a lack of self-sufficiency, and that niceness fixes systemic inequality. It is easy to be lulled into assimilation, so reflect often.
- Working together, we can build diverse and resilient communities.
 Revealing Luz: Illuminating Our Identities Through Duoethnography, Eaton, Carrie Diaz and Bailey, Luz Marizza, Journal of Humanistic Mathematics, 8, 2,(2018).
 Living Mathematx: Towards a Vision for the Future, Gutiérrez, Rochelle, Philosophy of Mathematics Education Journal, 32 (2017).
 On May 1st 2006 various protests and strikes occurred around the United States to demonstrate the importance of immigration to the United States.
 Embracing Nepantla: Rethinking “knowledge’’ and its use in mathematics teaching, Gutiérrez, Rochelle, REDIMAT, 1, , (2012). and Making Faces, Making Soul/Haciendo Caras: Creative and Critical Perspectives by Feminists of Color, Aunt Lute Books, (1990).
 Diaz Eaton, C. E. (2013). Modeling the Genetic Consequences of Mutualism on Communities (PhD dissertation).
 Quantitative Undergraduate Biology Education and Synthesis (QUBES): The Power of Biology X Math X Community (qubeshub.org).
 Donovan, Sam, et al. “QUBES: a community focused on supporting teaching and learning in quantitative biology.” Letters in Biomathematics 2.1 (2015): 46–55.