Once world-famous, biologist Edwin Grant Conklin revealed the mysteries of cells and fought to defend evolution
Edwin Grant Conklin, circa 1946
Edwin Grant Conklin, circa 1946
George Karger/Time & Life Pictures/Getty Images

It’s more important to know the Rock of Ages than the age of rocks!” thundered William Jennings Bryan to a crowd of 6,000 at the Hippodrome in New York in 1922. Three years before the Scopes “monkey” trial, Woodrow Wilson’s former secretary of state already was preaching against evolution and demanding, at a minimum, equal time for creationism in America’s classrooms. The staunch Presbyterian fulminated against college instructors who dared defy the Bible: “When a professor of science swells up and pushes the minister off the sidewalk ... he ought to be taught a lesson in comparative importance.”  

Bryan meant one professor in particular: Princeton’s Edwin Grant Conklin. Which was worse, Conklin had asked in pro-Darwin lectures across the country, “mud or monkey” — to trace humankind to the dust of Genesis, or to a simian? Now Bryan roared his reply: “I prefer mud. Everything I eat comes from the mud. The flower grows from the mud. I know all about mud. What has the monkey ever done for Professor Conklin, that should cause so much affection for it?”  

One hundred years have passed since Woodrow Wilson 1879 first hired the plucky Conklin to teach at Princeton, praising him as “one of the most distinguished biologists in America.” He would dominate the study of biology here for decades, as the first full-time head of the department (serving for 25 years) and as an inspiring teacher to thousands of undergraduates. Named for Gen. Ulysses S. Grant and born (as he loved to say) just days after President Lincoln delivered the Gettysburg Address, Conklin grew up on a farm in Ohio, son of a horse-and-buggy doctor and farmer who invented a new kind of beehive. In high school, the shy, gangly kid was too nearsighted for sports and was called “Hayseed” because he lived far outside of town. His love of nature blossomed at Ohio Wesleyan University, where his Yale-educated professor of natural history sent him searching for fossil shells of river mussels. Partway through college, he took time off to earn $35 a month teaching in a one-room school — serving as janitor, too. “It was one of the most valuable experiences of my whole life,” he recalled, “for it taught me self-reliance and confidence.”  

Conklin entered cutting-edge Johns Hopkins University in 1888 to study for his Ph.D. under biologist William K. Brooks. Biology then was electric with new ideas: the recent discovery of cellular meiosis and mitosis, the identification of mitochondria. Fellow students included Ross G. Harrison, Thomas H. Morgan, and Edmund B. Wilson, all of whom would become stars in their field. “It was as if I had entered a new world,” Conklin remembered, “with new outlooks on nature, new respect for exact science.” Choosing an area of research, he picked embryology and cell division, which seemed to lie at the center of the mystery of life. In particular, he wanted to understand cleavage patterns as cells split in the developing embryo. It had just been discovered that cells in developing frog embryos were not identical, but instead were preprogrammed to grow into certain body parts. Conklin wanted to see if this was true for other animals and to show exactly how the process works.

Marine eggs would make a good subject, he thought: abundant, transparent, easily manipulated in the lab. In the summer of 1890, he waded into the harbor near the U. S. Fish Commission at Woods Hole, Mass., and pried some slipper limpets (the orgiastic mating habits of which are suggested by the racy name Crepidula fornicata) from the shells of horseshoe crabs. Using a microscope and his prodigious memory, he traced the fate of every cell from conception to the fully formed larva, giving them names as they repeatedly divided (A, 1A, 1A1, 1A11, 1A111) and drawing a map of where they ended up. “Brooks thought this was totally absurd — counting cells — who gave a damn?” says Malcolm S. Steinberg, an emeritus professor of biology at Princeton, who once heard the elderly Conklin lecture at Woods Hole. But by counting those cells, Brooks’ bright pupil made an extraordinary breakthrough. “He showed the power of looking at things,” says Princeton molecular biologist Eric F. Wieschaus. “By following and tracking all the individual cells, he showed that cells divided in an orderly way that predicted what they were going to be. Intellectually, that was his fundamental idea, that you watch what cells do.” When the Conklins had a daughter, a friend teasingly suggested they name her Crepidula. Mrs. Conklin preferred Mary.  

The following summer, Conklin met up with Edmund B. Wilson at Woods Hole. Since receiving his Ph.D., Wilson had taught at Bryn Mawr College alongside Woodrow Wilson before being lured to Columbia by Dean Henry Fairfield Osborn 1877. As it turned out, Edmund Wilson was working on similar problems involving cell lineage, using a different species. Wilson and Conklin flipped through their notebooks, comparing their discoveries of cleavage patterns in mollusks and worms and finding them identical — as Wilson supposedly exclaimed, “By Jove, straight as a string!” The two friends were forging the modern science of developmental biology. Along with Johns Hopkins lab-mates Morgan and Harrison, they went on to found the Journal of Experimental Zoology; Wilson developed the chromosome theory of heredity, and Morgan made eternally famous that little fruit fly, Drosophila melanogaster.  

Conklin next turned his attention to the sea squirt (Styela), more closely related to humans than Crepidula is. Peering through a microscope, he made the greatest discovery of his life: Every gray Styela egg contains an orange-yellow crescent of pigment granules that divides into equal parts when the first cleavage occurs. This yellow-tinted region is preprogrammed for a specific future fate, he saw — it eventually becomes tail muscles in the larva. Conklin fed Styela eggs into a whirling centrifuge similar to the ones his father had used to extract honey from beehives on their Ohio farm. By redistributing the various regions of the egg, he could make eyes form inside the body and spinal cords grow externally — proof again that cells, even as they first begin to multiply from the egg, are destined to develop into specific parts.  

Professor emeritus John Bonner in his office in Guyot Hall with Conklin’s microscope.
Professor emeritus John Bonner in his office in Guyot Hall with Conklin’s microscope.
Frank Wojciechowski

“Five hours’ sleep are enough for him,” Time said. “In the evenings he reads voraciously — classics, new books, magazines, newspapers — and goes to bed after midnight. He smokes pipes, cigars, cigarettes, occasionally takes a drink. Sometimes he gives up smoking for the sake of his health, which is excellent, but his family soon persuades him to start again for the sake of his temper, which is excellent when he has something to smoke. On the radio he listens to practically nothing except comedian Eddie Cantor.”  

When Conklin showed undergraduates images of microscopic plants and animals, the professor himself studied them with “open-mouthed awe,” the magazine reported. “He really started biology at Princeton,” says John T. Bonner, a professor emeritus of biology, who got to know Conklin after World War II. Bonner had just joined the faculty and enjoyed visiting with the legendary scientist at his home at 139 Broadmead. Boisterously talkative, Conklin told Bonner how he came to Princeton from the University of Pennsylvania in 1908. Upon receiving Woodrow Wilson’s invitation, he at first was reluctant — Philadelphia was the scientific center of the nation, and little Princeton a backwater. Wilson’s dynamism finally convinced him, however, along with the promise of the best biological laboratory in the country, Guyot Hall, then being planned. “I shall come without hesitation,” he wrote to Wilson, “with full confidence of the situation at Princeton, and with high hopes for the future.”

The school was soon riven by that famous quarrel, however — Wilson versus Dean Andrew West 1874. Conklin, who had never forgotten being ridiculed as “Hayseed,” sided with the egalitarian president. When Wilson finally quit, Conklin despaired. “The prospect for the immediate future of Prince-ton seems to me very dark,” he wrote him. “Now it seems to me that we face disaster. ... I came to Princeton largely because of my admiration for you and your ideals, and if these are lost I shall feel that the spirit has gone out of the place.”  

But he was pleasantly surprised by Wilson’s successor, John Grier Hibben 1882, who defended Conklin’s book The Direction of Human Evolution (1921) when prominent Presbyterians demanded that the heretic author be fired. Hibben said Conklin was merely teaching what former president James McCosh had advocated 50 years earlier — that evolution is real, but it need not obviate religion. Conklin had become fascinated by evolution thanks to his interest in embryology: the development of the cell, the development of the species. In college he heard a professor excoriate the ungodly Origin of Species, which he “couldn’t touch with a 10-foot pole.” Conklin promptly had walked over to the library and checked the book out. At Johns Hopkins, his mentor Brooks inculcated a reverence for Darwin. In accepting his first job, at Ohio Wesleyan, Conklin served notice that he could not teach biology without teaching evolution.

As a new Penn professor, he lectured on embryology and evolution at the American Philosophical Society in Philadelphia in May 1896. In those days, many scientists still clung to the old Jean-Baptiste Lamarck hypothesis of “inheritance of acquired traits”: Giraffes stretch their necks, so their babies are born with longer necks, too. Conklin, by contrast, agreed with Darwin against Lamarck. Summoning his courage, he contradicted the other distinguished speakers. “Evolution doesn’t take place between adult organisms,” he declared, but instead in the “germ cells.” And within a decade, fellow scientists at home and abroad would prove him right, with a trio of spectacular discoveries that launched modern-day genetics: Mendel, mutations, chromosomes. Conklin’s prescient speech began a 56-year relationship with the APS, which he would twice serve as president through the invitation of an admirer, prominent Philadelphia lawyer Roland S. Morris 1896.  

In time, Conklin gave a thousand pro-Darwin public lectures. During the Scopes trial, Princeton students arranged a debate between him and a seminary professor in Alexander Hall. Conklin argued from his work as an embryologist: “The animal ancestry of the race is surely no more disturbing to philosophical and religious beliefs than the germinal origin of the individual.” In other words, why should Bryan recoil at being descended from apes, when once he was a mere egg bobbing in his mother’s womb? “The whole scientific world long since was convinced of the truth of evolution, and every year which has passed since the publication of On the Origin of Species in 1859 has added to the mountain of evidence which has been piled up in its favor,” Conklin said. Eventually, the public too would believe — but that might take “centuries.” In the meantime, he got plenty of hate mail, including from one writer who warned that his soul would sizzle in hell like a globule of water on a stovetop.  

Raised religious, in his youth Conklin earned a license to serve as a Methodist lay preacher. But attacks by pastors turned him away from the church even as his study of science caused what he called “my gradual loss of faith in many orthodox beliefs.” He resolved to direct his powerful voice at students in the classroom, not parishioners in the pews. At Hopkins, Professor Brooks had declared, “The idea of the supernatural is due to a misunderstanding; nature is everything that is.” Soon Conklin, too, abandoned his belief in miracles and pointed to nondivine sources for creation, development, evolution, and progress: “Do not nature and natural law reflect many of the qualities usually ascribed to deity?”  

But, like Darwin, he doubted whether “blind chance” possibly could have produced Homo sapiens — or even one human eyeball, with its marvelous complexity. “Surely there must be other factors than those now recognized by biologists to bring about such wonderful adaptations!” Conklin suspected that the answer — a mysterious “directing cause” — would be found to lie not with God, a deus ex machina, but within Nature itself, a deus in machina. The Religion of Science, he called it: “Everything in the universe is natural in origin and character.”  

His Religion of Science did not entirely scuttle his Christianity, however. Even as he first embraced On the Origin of Species, “I recognized its devastating effect on some traditional beliefs and tried to find ways of preserving the foundations of my faith,” he said. That faith became one of interpersonal ethics, not ultimate explanations for the origins of things. And he recognized that “the pantheistic God of science may command our awe, but scarcely our love. It is difficult if not impossible to love ‘Evolution.’” Ever valuable, traditional beliefs gave “strength and courage to mortal men,” giving them help to meet “desperate needs.”  

Like many scientists, Conklin grappled with the issue of eugenics, which reached its height in the 1920s. After the U.S. Supreme Court in Buck v. Bell upheld forced sterilization of the “feeble-minded” in Virginia (“three generations of imbeciles are enough”), most states followed suit. “All modern geneticists approve” such institutional segregation and sterilization, Conklin declared. In supporting eugenics he thought he was safeguarding the future of the Anglo-Saxon race, now that technology had abolished natural selection, that invaluable means of improving a species over time. “Evolution, either temporarily or permanently, has halted,” he told a reporter, adding that ancient Greece had far more geniuses per capita than modern America: Easy modern life had watered down the gene pool. “Natural selection must be replaced by intelligent human selection.”

“Conklin’s thoughts as a social reformer are as important as his science,” says Kathy Cooke, a historian of science at Quinnipiac University who places him in the larger context of the Race Betterment Movement in the Progressive Era and notes how his attitudes gradually shifted. “Conklin was a mild eugenicist, but he came around to a position of social evolution — not physiological. He thought of eugenics not as breeding and controlling, but how to improve the environment around people so they become better representatives of the ‘American Race’ — improving living conditions, inculcating a sense of social responsibility.” Eventually he became “a rebel against hard-line eugenics,” Cooke says. Paul Burnett, another historian of science and a researcher at the American Philosophical Society, agrees: “Conklin was an important critic of eugenics. Among scientists, few took a stand against it early on. His religious beliefs may have been a part of that.”

Although concerned for the future of his fellow Anglo-Saxons, Conklin rejected the virulent racism that many eugenicists displayed. As a boy he admired abolitionist John Brown; out of college, he taught freed slaves at a Methodist missionary school, Rust University in Mississippi — “a most necessary and humane work,” he called it, “Negro education.” “All human beings belong to the same species,” he assured audiences, and “the resemblances of all men, whether the Australian bushmen or the philosophers of the most civilized countries, are greater than their differences.” He grew pessimistic about eugenics-by-law: It never could “lead to progressive evolution,” but could only slow the general decline. Even with it, he believed, humankind probably would never produce another Shakespeare or Darwin.  

Once the Nazis co-opted eugenics, Conklin publicly condemned their “intolerance, bigotry, and prejudices.” He wrote, “Heredity is not responsible for social behavior, racial antagonisms are not born, but these antagonisms are carefully cultivated and developed.” Ever the teacher, he thought education was the answer. In 1946, he received a frantic letter from an Austrian doctor facing criminal charges for having been a eugenicist and, by implication, pro-Nazi. Would Conklin tell the court that the two were not the same — that many reasonable people worldwide supported eugenics? Conklin answered by denouncing Nazi ideas of “racial superiority and the forcible extermination of ‘inferior races’” yet defending his brand of eugenics: Some people are “hereditarially superior to others”; in all civilized countries, “seriously defective individuals” are properly prevented from breeding by institutionalization or “legalized sterilization”; and “an equally important measure is the assistance and encouragement of persons of good heredity to leave worthy descendants, for no social service is more important than this. If you have advocated these principles, as I have no doubt you have, you deserve praise rather than blame.”

Edwin Conklin retired from Princeton at 70 in 1933. But he kept coming to his lab on the second floor of Guyot Hall, southeast corner, and in a busy retirement he would churn out an additional three books and 93 articles. Working at a huge wooden table, he paused to read poetry to his laboratory assistant. The hallways echoed to his bellowing cries for the janitor to come up from the basement: “Clarence! CLARENCE!” At Reunions in 1943, H.L. Mencken had dinner at librarian Julian Boyd’s house on Broadmead and sat by Conklin, sipping Alsatian wine and Chateau Clemens. “He is a mousy old fellow with a white mustache, and somehow suggests a retired bookkeeper, but he is actually a biologist of the first chop,” Mencken told his diary. “We were soon on very good terms.” When some hapless guest spoke admiringly of research into psychic phenomena, “at once Conklin fell upon him with vigor” — soon joined by the ferocious Mencken. “I like Conklin very much,” the author wrote.

The subjects Conklin pioneered still are vital today. How cell development is regulated and steered into various future fates goes to the heart of the stem-cell debate. “Just recently, the mechanism of his ‘yellow crescent’ has been discovered,” says University of Maryland biologist William R. Jeffery, who, as Conklin did, works on sea squirts. “It contains a messenger RNA that encodes a protein that controls muscle growth.” Princeton’s Wieschaus credits Conklin with helping to lay the foundations of his own work, for which he won a Nobel Prize in 1995. “I look at embryos and try to figure out behaviors of cells by watching,” he says. “That’s clearly one of Conklin’s major messages from 100 years ago. Something mystifies you, and you say, ‘This can’t be happening.’ But if you sit and look at it in a careful and thoughtful way, the mechanism pops out.”  

John Bonner has preserved a crackly recording made of Conklin on his deathbed in November 1952. “I’ve often wondered why I came to attention as early as I did, and why people took any notice of what I had been doing,” the dying scientist mused. “I followed individual cells through the development, followed them until many people laughed about it.” But the laughter soon gave way to applause, which continues to this day. To honor his memory, the Society for Developmental Biology recently created the Edwin Grant Conklin Medal for members engaged in “distinguished and sustained research.” And in a small gesture, Bonner has put Conklin’s brass microscope on display near the latter’s former lab in Guyot Hall. It’s a reminder, he says, of Conklin’s many achievements and Bonner’s personal fondness for a kindly old man who revolutionized biology long ago: “I haven’t forgotten him.”   

W. Barksdale Maynard ’88 is a lecturer in the School of Architecture and the Princeton Environmental Institute.