Lauren Schroeder has loved dinosaurs since age 3 and bones since she was 10. In her second year of university, she started studying the early evolution of the Homo genus and it turned into her Ph.D. Many fossils have taken her breath away, she says, but a 2-million-year-old Homo habilis skull holds such a special place in her heart that it’s tattooed on her forearm.
As a paleoanthropologist at the University of Toronto, Schroeder works to untangle the various processes by which humans have evolved. One such process, natural selection, is adaptive: Changes in an organism’s features make it more suited to its environment. But some changes are not selected for, or even totally random. Despite the existence of “nonadaptive” processes, paleoanthropology has often attributed evolutionary changes in hominids to adaptation alone.
While a Ph.D. student at the University of Cape Town in South Africa, Schroeder questioned the emphasis on natural selection to explain changes seen in the fossil record. “It was very clear that something was missing,” she says. Not much research had considered the role played by nonadaptive processes, such as genetic drift and gene flow. “That was really the big moment for me … these are important questions that haven’t really been asked. I should try to answer them.”
Since then, her research has suggested that nonadaptive processes play a much bigger role in evolution than previously realized.
2023-07-11 07:00:00
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