The Sixth Extinction Major Figures

Elizabeth Kolbert

Elizabeth Kolbert (1961–) is the author of The Sixth Extinction: An Unnatural History and an award-winning environmental reporter. In the book, Kolbert travels the globe interviewing experts and visiting conservation and research centers in her quest to identify the signs that point to the upcoming Sixth Extinction. Kolbert’s text reveals humans as the primary antagonists in this event.

Charles Darwin

Charles Darwin (1809–82) was a British naturalist who proposed the theory of natural selection in On the Origin of Species (1859), a book that shaped people’s understanding of evolution. Darwin’s ideas influence Kolbert’s understanding of extinction.

Jean-Baptiste Lamarck

Jean-Baptiste Lamarck (1744–1829) was a French biologist who published works outlining an early theory of evolution. Though he was largely ridiculed in his time, his theories garnered the interest of later scientists, including Cuvier and Darwin.

Georges Cuvier

Georges Cuvier (1769–1832), a French zoologist, is regarded as the father of paleontology (the study of past geological periods using fossils). Cuvier proposed the first theory of extinction using fossils from the American mastodon. He also believed in catastrophism, the idea that catastrophic events caused species to die out suddenly. However, Cuvier rejected the role of evolution in the formation of new species.

Charles Lyell

Charles Lyell (1797–1875) was a Scottish geologist who championed uniformitarianism, the idea that Earth’s landscapes change slowly over time.

Alfred Newton

Alfred Newton (1829–1907) was a British zoologist who determined that the great auk (a flightless seabird) was extinct. He dedicated his career thereafter to protecting birds and other forms of wildlife.

Walter Alvarez

Walter Alvarez (1940–) is an American geologist who, in the 1970s, discovered a worldwide layer of clay containing high iridium levels, which he proposed to be evidence of an asteroid or comet hitting Earth about 65.5 million years ago. Further, Alvarez theorized that the asteroid’s dust created catastrophic temperature changes, which killed the dinosaurs.

Luis Alvarez

Luis Alvarez (1911–88), father of Walter Alvarez, was an American physicist. He helped his son pursue the theory that an asteroid hitting Earth had killed off the dinosaurs. Luis also helped Walter publish his scientific paper on the topic in the 1980s.

Thomas Kuhn

Thomas Kuhn (1922–96) was an American philosopher and historian of science who developed the idea of paradigm shifts. Kuhn argued that scientific inquiry is linked to an overarching worldview, or paradigm, made of shared frameworks, basic assumptions and modes of inquiry. Eventually, the paradigm reaches a point where the paradigm’s flaws become unsurmountable, resulting in an intellectual revolution, or a paradigm shift. The shift creates new ways to do science.

Jan Zalasiewicz

Jan Zalasiewicz is a British geologist who, with his colleagues, formally proposed that Earth is currently in the Anthropocene Epoch, a geological interval marked by human influence substantially altering the Earth. The Anthropocene begins in the 1950s.

Paul Crutzen

Paul Crutzen (1933–) is a Dutch chemist who received the Nobel Prize in chemistry in 1995 for demonstrating nitrogen oxide’s effects on the atmosphere. He brought attention to the idea of the Anthropocene Epoch.

Svante Pääbo

Svante Pääbo (1955–) is a Swedish geneticist and the director of the Max Planck Institute for Evolutionary Anthropology. He is a founder of paleogenetics, the study of ancient DNA.

Paul Ehrlich

Paul Ehrlich (1932—) is an American biologist and ecologist. He is well-known for his writings on the dangers of overpopulation. Ehrlich spent most of his career as a professor at Stanford University, retiring in 2016. Kolbert quotes him in The Sixth Extinction.

David Raup

David Raup (1933–2015) was an American paleontologist who applied statistics and mathematical models to his studies in evolutionary biology and paleontology. He theorized that mass-extinction events happen at regular 26-million-year intervals.