Hoekstra was born to a family of Dutch ancestry. Hoekstra's first name "Hopi" is derived from a Dutch term of endearment. Hoekstra attended a high school near Palo Alto, California. She chose to attend college at the University of California, Berkeley, where she initially intended to study political science. She chose the university because she wanted to play volleyball, which she did for two years. She has stated that at one point she wanted to become the U.S. ambassador to the Netherlands, but she was drawn into biology by a class on biomechanics taught by Robert J. Full. She went on to work in Full's lab, studying cockroachlocomotion.
Career
Hoekstra received her B.A. in Integrative Biology from the University of California, Berkeley. Before her graduate studies, she researched grizzly bears for a year in Yellowstone National Park. She obtained her Ph.D. in Zoology as a Howard Hughes Predoctoral Fellow at the University of Washington. For her postdoctoral work, she studied the genetic basis of adaptive melanism in pocket mice at the University of Arizona. In 2003, she became an assistant professor at the University of California, San Diego. In 2007, she moved to Harvard University, where she received tenure in 2010. She is a member of the advisory board for Current Biology.
Research
Hoekstra is best known for studying the genetic mechanisms that influence the evolution of highly complex natural behaviors. In 2013, Hoekstra published an article in the journal Nature on the genetics of burrowing behavior in two sister species of Peromyscus mice; the oldfield mouse, which builds elaborate burrows complete with an escape tunnel, and the deer mouse, which builds a simple and shallow nest. Using a combination of behavioral assays and classical genetic strategies, Hoekstra and her students identified four regions of DNA which control the length of the tunnels dug by the mice. Students in her lab have also studied the connections between digging behavior and the neurobiology of reward. She has also studied the evolution of the color of mice coats and its significance for adaptation. In 2013, her team published an article in the journal Science, describing how coat color in mice was controlled by nine separate mutations within a single gene, named "agouti." Speaking about this discovery, Hoekstra said, "The question has always been whether evolution is dominated by these big leaps or smaller steps. When we first implicated the agouti gene, we could have stopped there and concluded that evolution takes these big steps as only one major gene was involved, but that would have been wrong. When we looked more closely, within this gene, we found that even within this single locus, there are, in fact, many small steps." Her work supports the hypothesis that evolution can occur through incremental changes.