Niles Eldridge | Biography

Niles Eldredge is a paleontologist best known for a theory he developed with fellow paleontologist Stephen Jay Gould called punctuated equilibrium--an evolutionary theory that challenged Darwinian gradualism and changed the way scientists interpret the fossil record. A curator of invertebrate paleontology at the American Museum of Natural History in New York, Eldredge has used the fossil record to improve current theories of evolution, and he has applied some of these theories to better understanding the problems faced by living species. Eldredge is a staunch opponent of the so-called "scientific creationism" movement, and he remains a prolific author.

Eldredge was born in Brooklyn, New York, to Robert and Eleanor Eldredge. His father was an accountant and his mother a homemaker. As a young boy growing up in the northern suburbs of New York City, he would sometimes venture into the city and visit the American Museum of Natural History. Eldredge planned to study classics when he entered Columbia University in 1961; he intended to become a lawyer but discovered himself increasingly fascinated with academic research.

Eldredge met his future wife, Michelle J. Wycoff, at Columbia University; she introduced Eldredge to various members of the anthropology department and he began taking courses in this subject. His participation in an ethnographic study turned his attention toward evolution. In the summer of 1963, he served as a trainee with anthropologists studying in a Brazilian fishing village, and he began collecting invertebrate (having no spinal column) fossils from the surrounding reef. After taking courses in paleontology and geology the following semester, Eldredge, recalled in his book Fossils: The Evolution and Extinction of Species, "embarked on a lifetime career of trying to make some sense of the fossil record of the history of life." On June 6, 1964, he married Wycoff, with whom he would have two sons. He received his bachelor's degree in anthropology in 1965, graduating summa cum laude.

While still an undergraduate, Eldredge met Stephen Jay Gould, who was then a graduate student two years his senior. They both shared an interest in scrutinizing the fossil record of invertebrates at the species level. By the time Eldredge began graduate studies at Columbia University, his interest in invertebrate paleontology had turned to the Paleozoic era, and it was from this era that he chose the subject for his Ph.D. thesis, trilobites. Trilobites lived between 530 and 245 million years ago and they represent one of the earliest groups of arthropods--invertebrate animals with jointed limbs. Fossil evidence has been collected from all over the world which establishes that they existed in a diverse range of environments over an extremely long period of time.

After receiving his Ph.D. in geology from Columbia University in October of 1969, Eldredge assumed the post of adjunct assistant professor in Columbia's geology department, while simultaneously holding a position as an assistant curator in the American Museum of Natural History's department of invertebrate paleontology. By 1971, his work on Paleozoic invertebrates had led to a rethinking of the evolutionary process; he published his theory in the journal Evolution. Frustrated that he could find no evolutionary changes in his trilobites despite their wide distribution over time and space, Eldredge conducted a more detailed examination of his specimens. "Then I started noticing these very slight patterns of differences between the eyes in different populations," he told Andrew Spizzirri during an interview. "I looked at these in terms of where they were distributed on a map, and how they were distributed in time, and saw that there were these great periods of stability that were interrupted at varying intervals by small, but definitive change, and the change seemed to be concentrated at these short intervals." The following year, Gould contributed to Eldredge's hypothesis. Republished in the collection, Models in Paleobiology, their theory of "punctuated equilibrium" seemed to contradict certain fundamental elements of Darwinian evolution.

Darwin argued that evolution was gradual and continuous, but his concept of a gradual progression of species over time was often marred by gaps in the fossil record, although he believed these would eventually be filled by later research. In the early 1940s, the American paleontologist George Gaylord Simpson suggested that these gaps were not necessarily the result of a poor fossil record and speculated that evidence of continuous evolution might never be found. He went on to delineate the circumstances in which abrupt changes could occur, but he limited the scope of his research to the larger groups, like whales and bats, because he believed that specific species, the individual constituents of groups, were not important to this process. Eldredge and Gould redefined Simpson's theories by concentrating on species, where they were able to incorporate aspects of speciation theories that suggested that the branching off, or budding, of lineages served as the primary mechanism for abrupt change. In the theory proposed by Eldredge and Gould, change is only abrupt relative to geological time and the long history of evolution. "Most anatomical change in the fossil record," Eldredge told Neil A. Campbell in the American Biology Teacher, "seems to be concentrated in relatively brief bursts punctuating longer periods of relative stability." The theory of punctuated equilibria initially met with mixed reviews and still has its opponents, though leading evolutionary biologists tend to agree that stasis plays an integral role in the process of evolution.

In 1972, Eldredge became adjunct professor of biology at the City University of New York; in 1974, he advanced to associate positions at Columbia University and the American Museum of Natural History, where he was named curator of the department of invertebrate paleontology in 1979. As an extension of his work on species, Eldredge began to look at the hierarchical relationships of living systems, working to define the interactive nature of organisms and their environments within successively larger systems. "Large scale entities--ecosystems, species, social systems--are real entities in and of themselves composed of parts," Eldredge explained to Spizzirri. "Just like organisms are composed of parts and organisms are parts of populations, populations are parts of these larger scale systems."

In the early 1980s, Eldredge unwillingly became the subject of controversy over scientific creationism. Creationist leader Luther Sunderland co-opted the theory of punctuated equilibria and, using the ideas of stasis and gaps in the fossil record, he claimed it could disprove evolution. After conducting an interview with Eldredge under the guise of being a consultant for the New York State Board of Regents, Sunderland apparently referred to Eldredge as an advocate for the simultaneous teaching of evolution and creationism in the classroom. Embarrassed and angry, Eldredge wrote an article for the New Republic, denouncing claims of scientific creationism as bad science, if even science at all. He later expanded the article into the book The Monkey Business: A Scientist Looks at Creationism, and he has written other critical pieces against the movement.

Eldredge has continued to study events of the geologic past, with a particular interest in the connections between environmental change and speciation and extinction, as well as the role these events play within living systems. Looking at the mass extinctions of the past, Eldredge has tried to derive from them answers that might help solve modern concerns about biodiversity. Examples from the past have shown that when habitats are radically and abruptly altered and organisms are unable to find similar or suitable habitats elsewhere, they will become extinct. He believes extinction has played a critical role in the emergence of new species, particularly humans, as he told Neil A. Campbell in the American Biology Teacher: "There is nothing inevitable in the system that human beings would emerge. And that is where the importance of extinction really is--it reshuffles the deck." Eldredge also argues that evolution is not necessarily good, and asserts that our survival depends on the survival of other species in the complex global ecosystem.