I reminded my friend that, because intelligent design argues for supernatural causes of natural phenomena, teaching it would undermine rational inquiry, together with students’ ability to eventually make the kind of scientific breakthroughs we are enjoying today. I pointed out the U.S. National Institutes of Health’s Human Microbiome Project as an example, which is revealing how human health suffers when the health of the millions of microorganisms with which we’ve coevolved suffers. My friend’s simplistic interpretation of evolution as “survival of the fittest” left him ignorant even of the possibility of projects like this, which are based on evolutionary considerations of symbiosis. Evidently, educators—and certainly evolutionary specialists themselves—must broadcast a more nuanced story of evolutionary theory. Otherwise, future scientists and projects that inform better approaches to human health and global ecology will be sabotaged before they even emerge.
Science education has failed to overcome entrenched cultural ideals rooted not only in religion, but also in political philosophy. For those like my engineer friend trying to comprehend how magnificent structures of life emerge by means of “survival of the fittest,” skepticism is understandable. Popular appreciation for life’s complexity has far outpaced the popular interpretation of the evolutionary source of that complexity, which has remained stuck in 1864, when Herbert Spencer coined the phrase “survival of the fittest.”
When it comes to the story of evolutionary science, people know the name Charles Darwin, but most do not know the names Ivan Wallin or Lynn Margulis—two more recent, groundbreaking evolutionary theorists. Over the past several decades, these and other researchers have revealed that organisms’ cooperation and interdependence contribute more to evolution than competition. Symbiogenesis—the emergence of a new species through the evolutionary interdependence of two or more species—is at least as important in the history of life as survival of the fittest. Such insight has failed to gain traction in American minds—including those of American scientists—because of cultural history traceable back through the popularization of Adam Smith’s individualist philosophy. (...)
According to Margulis, the evolving relationships between microscopic organisms and other micro- and macroscopic organisms are the essence of the history of life. Despite scientists’ mid-century focus on eukaryotic life (organisms with larger cells featuring a bounded nucleus and organelles), the most prolific type of organism on Earth, bacteria, is prokaryotic (an organism without a bounded nucleus). Virtually all eukaryotic forms of life have adapted symbiotic associations with prokaryotic bacteria. Margulis was among the first Western scientists to attempt to popularize this fact. She spent virtually her entire career laboring to bring this mostly microscopic form of evolution to the macroscopic focus of her readers.
Margulis’s research in microbiology equipped her to verify and expand on Wallin’s symbiosis-centered theory. In 1966 she attempted to publish a summary of her perspectives on the evolution of complex life forms in “The Origin of Mitosing Eukaryotic Cells,” only to be rejected by more than a dozen scientific journals. When her article was finally published by the Journal of Theoretical Biology, criticism ensued. Nonetheless, the further Margulis pushed her symbiotic evolutionary theory, the more convinced she became that the emergence of eukaryotic cells a billion and a half years ago—a major evolutionary transition in the history of life—was the result of symbiogenesis.
In Margulis’s view, out of prokaryotic–prokaryotic symbiosis emerged eukaryotes. Out of prokaryotic–eukaryotic symbiosis emerged more competitive eukaryotes. And out of eukaryotic–eukaryotic symbiosis emerged multicellular life. The classic image of evolution, the tree of life, almost always exclusively shows diverging branches; however, a banyan tree, with diverging and converging branches is best. To this day, many scientists and most laypeople remain ignorant of this way of imagining evolution, which profoundly constricts how they imagine themselves.
by Bradford Harris, American Scientist | Read more:
Image: Endosymbiosis: Homage to Lynn Margulis, by Shoshanah Dubineer
