Resolution of Respect: Conrad Alan Istock (1936–2023)

Abstract

Conrad Istock was an important contributor to the emerging field of evolutionary ecology starting in the 1960s. His best-known work in this area blended theory and field and laboratory studies of pitcher-plant mosquitoes. Conrad died March 8, 2023, in Ithaca, New York, USA.

Conrad Alan Istock was born August 31, 1936, and grew up in Grosse Pointe Park, Michigan, USA, along with one sister and two brothers. During childhood, Conrad was shy, but he sang in the church choir along with his mother, took up playing the violin, which became a lifelong passion, and was an enthusiastic Boy Scout, eventually becoming an Eagle Scout. He loved the outdoors and his troop's camping trips further stimulated his lifelong fascination with nature.

Conrad matriculated at Wayne University (now Wayne State University) in Detroit in the fall of 1954. His circuitous path through college makes his career as a biologist seem far from inevitable. He first enrolled in the College of Engineering. In the winter of 1956, he transferred to the pre-education curriculum in the College of Liberal Arts and then in the winter of 1957 to the College of Education as a “science” major. He intended to be a high school teacher. It was not until the spring of 1956, his fourth semester in college, that he took “General Biology,” which was his first course in biology. He took one biology course in each of the following four semesters. As he entered his last year of college in the fall of 1958, only five of the forty-three courses he had taken were in biology. His last year was different, as six of his nine courses were biology. We describe below what sparked this change. In his last semester, he transferred back to the College of Liberal Arts and became a biology major. He graduated in June 1959 with a B.A.

Conrad's undergraduate years must have been especially stimulating for two reasons. The first is that the Biology Department at Wayne served students having a great diversity of educational goals. This is reflected in the courses it offered, which included Bacteriology, Comparative Anatomy, Endocrinology, Histology, Immunology, Invertebrate Zoology, and Ornithology, as well as courses such as Antiseptics and Disinfectants, Microbiology for Contract Nurses, Industrial Microbiology, and Scientific Aspects of Disease Control for students entering healthcare and public-health professions. The second reason is that the number of matriculated students increased from 11,293 in 1945–1946 to 26,556 in 1955–1956 (Hanawalt 1968:360) and the operating budget increased from 4.3 million dollars in 1945–1946 to 16.5 million dollars in 1955–1956 (Hanawalt 1968:370). Both increases must have contributed to a sense at Wayne of growth and of optimism about the future, which we believe inspired Conrad. Despite setbacks and disappointments (see below), this optimism never left him.

Inside the classroom, Conrad received a broad education in biology. Several late 1950s, biology faculty were active researchers, including William Duellman (Mendelson 2022) and especially Charles Creaser, who taught ichthyology at Wayne and at the University of Michigan Biological Station (UMBS) and who likely influenced Conrad to pursue graduate studies in biology at his alma mater, University of Michigan. Creaser published ecological, endocrinological, and natural historical studies mostly in ichthyology (e.g., Creaser 1929, 1930, Creaser and Gorbman 1939) and was the first to describe the potential of zebrafish to be a model organism for studies of vertebrate development (Creaser 1934, Varga 2016). Creaser was an “inspiring teacher” (Gorbman 1965); we suspect Conrad shared this opinion, as he had direct experience with Creaser as a teacher and he chose Creaser as his advisor when he became a biology major in 1959.

Outside the classroom, Conrad must have received a broad education in the human experience. Many of his fellow students were children of factory workers as Detroit was then the center of the United States automobile industry, and likely, many were the first of their family to attend college. During and after World War II, the auto manufacturing plants and subsidiary plants supplying them attracted hundreds of thousands of workers from a wide variety of ethnic backgrounds, including many Black Americans who sought a better life then unavailable to them in the American South (Sugrue 2005:19–31). In the 1950s, “Detroit the Dynamic” was still near its industrial zenith as the “arsenal of democracy” that arose from the enormous World War II demand for industrial goods (Sugrue 2005). The city was a center for progressive politics and labor activism, which in part was manifested by substantial involvement in local and state politics by the American Federation of Labor and Congress of Industrial Organizations and especially the United Autoworkers Union (UAW; Greenstone 1977:chapter 4). In 1949, the UAW had ~217,000 members in Detroit alone (Molyneux 2023). The labor movement, left-wing politics, and the civil rights movement were “in the air” at Wayne and in Detroit. We believe this exposure deeply impressed Conrad and led to his substantial commitment to liberal politics and social justice described later.

Conrad's education at Wayne was complemented in the summer of 1958 by his enrollment at UMBS where he took the Ornithology course taught by Harrison Tordoff (Gill 2009) and the Ichthyology course taught by Creaser. Both courses exposed Conrad to a forward-thinking researcher having a deep knowledge of natural history. We suspect this experience sparked his decision to become a biology major and eventually to become a biologist whose career embodied the combination of strengths he was exposed to by these two teachers.

In the fall of 1959, Conrad entered the PhD program in the Zoology Department at the University of Michigan. Faculty members in the department and in the Botany Department included Francis Evans, Nelson Hairston, Larry Slobodkin, Fred Smith, Theodore Hubbell, Frederick Sparrow, and others who were influential researchers in the 1960s and thereafter, especially in community and evolutionary ecology (Evans 2003, Wilbur and Gill 2008, Colwell and Futuyma 2011, Paine 2013). Conrad's educational focus was now biology (save for one physics course and two Russian courses). He received an A- or higher in 18 of the 22 biology courses he took. He honed his lifelong non-hierarchical engagement in scientific debate in a weekly ecology seminar presided over by Hairston, Slobodkin, and Smith. Recent articles as well as presentations of research by graduate students were discussed. A fellow graduate student, Bruce Levin, recalls that Conrad was an inspiration to him because he always got to the core of a contentious issue in a way that improved the debate (Levin 2023).

Conrad's PhD thesis project was a study of the “Distribution, Coexistence and Competition of three whirligig beetle species of the genus Dineutes (Gyrinidate, Coleoptera).” His committee consisted of Slobodkin (chair), Hairston, Hubbell, and Sparrow. Conrad described the distributions of three species (D. assimilis, D. horni, and D. nigrior) from the bottom to the top of Michigan and hypothesized that they were governed by competition for food. The results of laboratory experiments in which species were reared together under food-limited conditions supported this hypothesis. This study was one of a few at the time that combined field and laboratory studies in an investigation of the causal basis of the structure of an ecological community. The resulting publication (Istock 1966) was Conrad's first. He later described the competitive displacement of one species of whirligig beetle by another in one generation (Istock 1967a).

In 1960, Conrad met Nancy Smith (1935–2020) when both were enrolled in a Plant Ecology course at UMBS and they married in 1961. They and their daughters (Alice Istock Stone, 1964–2017, and Anne Istock Keys, 1966–) were at “Bug Camp” many summers, with Conrad either teaching courses such as evolutionary ecology, conducting research, or both. Conrad's last summer at UMBS was in 1987. This long association has been honored by an Istock Family Scholarship Fund, which gives financial aid to students attending UMBS (https://giving.umich.edu/um/w/istock-family-scholarship-731433).

After a one-year position at the University of Illinois, in 1965 Conrad joined the Department of Biology at the University of Rochester, New York. It is in Rochester that Conrad's professional life developed in two very different ways.

The first way was typical for any assistant professor. Conrad established a research career. His initial work was the description of the community dynamics of two corixid bug species (Istock 1973). He later showed that the changes in numbers of the two species agreed well with Volterra's logistic model of interspecific competition (Istock 1977).

Conrad then began his study of the evolutionary ecology of the pitcher-plant mosquito, Wyeomyia smithii. Conrad and collaborators first described how interactions between resource levels and intraspecific competition for resources affect development time and tendency to enter larval diapause in natural and laboratory populations (Istock et al. 1975, 1976a, b, Moeur and Istock 1980). They beautifully demonstrated how natural selection favors reduced larval diapause tendency during spring and summer, and then, favors increased diapause tendency later in the year because diapause allows the population to overwinter. The net consequence of these countervailing influences is the maintenance of heritable variation for a fitness trait. These studies and their theoretical interpretation were reviewed in Istock (1978, 1981, 1982, 1985). Further laboratory studies examined genetic effects on life history characteristics in crosses between mosquitoes from populations from northern temperate and subtropical climates (Istock 1982). In addition, Moeur and Istock (1982) described extensive chromosomal inversion polymorphism in a population and Istock and Weisburg (1987) described among-population polymorphism at two electrophoretic loci and suggested that the pattern of variation at each locus was governed by natural selection. Scheiner and Istock (1991) also conducted an artificial selection experiment to investigate how that the phenotypic correlation between development time and diapause tendency constrains the direction and magnitude of life history evolution in this species.

Conrad conducted other empirical work as well. He and collaborators analyzed the structure of forest moss communities (Coleman and Istock 1980), developed a statistical tool to compare communities in mosaic landscapes and to detect patterns of change across an entire landscape (Istock and Scheiner 1987, Scheiner and Istock 1987), and analyzed changes in vascular plant communities in the hemlock–white pine–northern hardwood transition zone in Northern lower Michigan (Scheiner and Istock 1994). He and collaborators also theoretically explored ecological dynamics (Streifer and Istock 1973) and the interactions between ecological and evolutionary processes (Istock 1967b, 1970a, Tuljapurkar and Istock 1993).

This must have been a bitter defeat. However, Conrad remained true to his progressive ideals, as we discuss later.

The dual nature of Conrad's professional life during the late 1960s to mid-1970s was remarkable and is even more so when viewed retrospectively. He received tenure as an associate professor in September 1968, and his research was funded by the National Science Foundation starting in 1967 and for many years thereafter. Yet, in his first 10 years at the University of Rochester (1965–1974), nine of his 16 publications concerned environmental and political issues unrelated to his research, such as the Vietnam War (Istock 1967c, 1971a), the environmental crisis (Istock 1969, 1971b, c, d, e), and environmental policy and practices (Istock 1974, Istock et al. 1974).

In 1970, Conrad chaired the Black Studies Committee, which recommended that the university establish a “Center for Afro-American Studies” (Anonymous 1970a), and he also moderated a debate between William Buckley and Bill Kunstler on the “American Judicial System.” The Rochester newspaper described Buckley's position as “Repair It” and Kunstler's position as “Scrap It” and judged the event a “sometimes comic debate” (Anonymous 1970b). The article noted that the audience applauded Conrad's remark as moderator that “neither man seems to have suggested any workable change in the American judicial system.”

Conrad ended his speech with “My last question: what are you doing here, anyway?” The response of the students is unknown. The Rochester newspaper's article on the speech was entitled “Diplomas A Joke, says UR Prof” (Anonymous 1970c).

Conrad also engaged with the Rochester community. He contributed to a panel discussion of “overpopulation” at a meeting of Zero Population Growth (Anonymous 1970d), he opposed the building of an oil tank farm at the Port of Rochester and presciently noted that “It is impossible to continue expanding our consumption of foreign oil without causing greater economic and social turmoil in the world” (Anonymous 1973), and he co-led a “lesson” in world hunger at a local high school, which involved a “26-hour fast to experience hunger first-hand” followed by a “meal-game” in which students each received a “first-, second-, or third-world meal” to break the fast. A reporter noted that “It wasn't clear what [the students] learned from the experience” (Gallagher 1975).

Conrad's more direct involvement in political and social issues diminished in the later 1970s. He was a close friend of some of his colleagues, especially the behavioral ecologist Jerram Brown (Anonymous 2016) and the geneticists Ernst Caspari (Eicher 1987) and Uzi Nur (Normark and Ross 2010). His research on Wyeomyia continued (see earlier). After the arrival in 1975 of graduate student Julia Bell Graham, his research included studies of the interaction between natural selection, recombination, and transformation in Bacillus subtilis (Graham and Istock 1978a, b, 1979, 1981). They demonstrated that strains could exchange genetic material via transformation when grown in soil microcosms. In initial experiments, a single recombinant came to dominate the populations. Further experiments with differentially marked isogenic strains showed that a recombinant strain does not always exhibit a growth advantage. The outcome of natural selection depends on environmental conditions and on the starting ratios of the parental strains.

In 1984, Conrad accepted the position of Chair of the EEB Department at the University of Arizona. He had no prior experience with an administrative task at this level. Conrad was a passionate advocate for the department and helped expand it, with 12 faculty members added between 1985 and 1991 when his chairmanship ended. These hires added evolution and genetics to the strengths of the department, alongside its strength in ecology.

Having left the Northeast, Conrad's work on pitcher-plant mosquitoes ended and he focused on bacteria. He and collaborators demonstrated that recombination was frequent within but not between clonal population structures of B. subtilis and of B. licheniformis strains from the Sonoran Desert (Istock et al. 1992, Duncan et al. 1994). Strains of B. subtilis and B. licheniformis were shown to exchange genetic material in soil culture. However, the interspecies hybrids were unable to persist, suggesting that in nature, the boundaries between these species are maintained (Duncan et al. 1989). Istock et al. (2001) described deeply separated genomic lineages of B. subtilis from Africa, Asia, and North and South America, which are globally distributed and coexist in local populations. Some of these lineages are also further subdivided within local populations. These genomic divisions were unrelated to variation in several phenotypic traits. These findings raised still unresolved fundamental questions regarding the nature of bacterial species: Should the definition be phenotypic or genomic? If genomic, are the deep sublineages species? Conrad and collaborators grappled with these questions in a detailed analysis of bacterial species concepts (Istock et al. 1996).

Conrad and collaborators also explored the interactions between lytic and temperate bacteriophage and B. subtilis, leading to the suggestion that the intertwined life histories of temperate phage and their hosts do not fit the ecological paradigms of parasite and host or of predator and prey (Pantastico-Caldas et al. 1992). A second study relevant to bioremediation concerned a conjugative plasmid carrying genes encoding enzymes for naphthalene degradation and its host, Pseudomonas putida (Duncan et al. 1995).

We see here Conrad's disappointment about what he viewed as the failure of reason and dialogue to achieve an outcome beneficial to all. This failure echoed his experiences decades previously in struggles over environmental, political, and social issues. The Mount Graham International Observatory now consists of three telescopes (https://mgio.arizona.edu/). The population of Mount Graham Red Squirrels is still “Endangered” according to the U.S. Fish and Wildlife Service; its numbers fluctuated between two and three hundred for many years after the telescopes were installed. The population dropped after a 2017 wildfire and a 2022 survey estimated that there were 156 individuals (Frederico 2022). The Mount Graham observatory controversy continues to attract attention (Helfrich 2019).

Conrad's last research publications concerned geographic diversity of genetic variation in B. subtilis (Istock et al. 2001), the description of a new species, B. sonorensis (Palmisano et al. 2001), and the origin of life (Istock 2010).

Conrad's third book is a collection of “Stories for Children of All Ages” (Istock 2016b) that embodies the same aspiration for courage and cooperation. It draws heavily on Conrad's knowledge of biology, with some stories involving real or imaginary animals, and on many parts of his personal life, such as his love for dogs (Boxers), playing the violin, and his love of family and of community.

It is sobering to realize that someone with Conrad's conception of a career as a biologist would never be hired at a research university in 2024. Grantsmanship, a publish-or-perish mentality, academic networking, and citation counts were foreign to him. Conrad had many faults and foibles. But his North Star was his passion for the pursuit of wisdom and for truth and justice. He shared this passion with each of us. We are all the better for it.

Ave Atque Vale