When I began teaching in September 2001, in a public high school in Goddard, Kansas, my new colleagues were still sighing with relief. Just two years earlier, the Kansas State Board of Education had effectively diluted the treatment of evolution in the state science standards. Fortunately, the reaction from the electorate was swift. In February 2001, the composition of the board had changed in an election, and the previous, more complete, treatment of evolution had been restored.

Unfortunately, in 2005, the composition of the board changed again, and a new set of state science standards, rewritten under the guidance of local creationists to misrepresent evolution as scientifically controversial, were adopted. Thankfully, however, the voters again expressed displeasure, and the composition of the board changed once again. In 2007, the board adopted a set of standards treating evolution in a scientifically responsible and pedagogically appropriate way.

My colleagues and I didn’t know whether to laugh or to cry. Science standards are central to science instruction, determining the content not only of curricula but also of textbooks, statewide testing, preservice teacher coursework, and inservice teacher development. So a degree of stability in the standards is crucial. But in the course of just eight years, the treatment of evolution in the Kansas standards swung repeatedly between admirable and deplorable and back again.

If the “evolution haters” hoped to inhibit the teaching of evolution in our public schools, they were disappointed. At least in my school, my colleagues and I were determined to continue teaching evolution forthrightly. Moreover, we were committed to retaining evolution not only in our classrooms but also in our shared standards, even testifying against the proposed changes to the standards at a town hall meeting organized by the state board in 2005.

Whether because of the repeated public controversies over the teaching of evolution or not, I heard the same old questions back in the classroom: Isn’t evolution just a theory? Where are the missing links? If humans descended from monkeys, why are there still monkeys? By chance, one student had two opportunities to give me grief about evolution, as a freshman in biology and as a senior in AP biology – but that story has a happy ending, as we will see.

Nevertheless, it was something of a victory when, in 2013, Kansas adopted the Next Generation Science Standards (NGSS), in which evolution figures as a disciplinary core idea of the life sciences. Of course, the decision was not welcomed by all: a local creationist organization even went so far as to file a lawsuit alleging that the decision was unconstitutional. However, my colleagues and I hoped that the result would represent a long-term improvement in the presence of evolution in the science classroom.

Evidence from a pair of national surveys suggests that our hopes were realized. In 2007, researchers at Penn State launched a national survey of public high school biology teachers aimed at ascertaining whether, what, and how they taught about evolution. In collaboration with Eric Plutzer, one of the original researchers, the National Center for Science Education conducted a replication of that survey in 2019 and found a dramatic shift in the emphasis on evolution.

In the original survey, 51% of the teachers reported emphasizing the broad scientific consensus on evolution while not endorsing creationism as a scientifically credible alternative. By 2019, that was up to 67%! This increase was matched by decreases in the numbers of teachers who emphasize both evolution and creationism (from 23% to 12%), teachers who emphasize neither (from 18% to 15%), and teachers who endorse creationism while not endorsing evolution (from 8.6% to 5.6%) (Figure 1).

Figure 1.

Reported emphases in evolution instruction among U.S. public high school biology teachers, 2007 and 2019.

Figure 1.

Reported emphases in evolution instruction among U.S. public high school biology teachers, 2007 and 2019.

It is likely that the NGSS played a substantial role in this change. In 2007, teachers in states that would later adopt the NGSS were less likely to endorse evolution and not creationism than the national average. In 2019, they were more likely to do so. Teachers in NGSS states reported having taken more preservice and inservice coursework on evolution than their colleagues elsewhere, suggesting that the increased expectations encouraged teachers to upgrade their own knowledge of evolution.

There is still much work to do. According to the new survey, more than one in six public high school biology teachers are still endorsing creationism as a scientifically credible alternative to evolution in their classrooms, and almost as many of them are failing to emphasize the broad scientific acceptance of evolution. Unfortunately, many non-NGSS states still have state science standards with inadequate expectations for evolution education.

We should all take pride in efforts to support the formulation and adoption of standards that, like the NGSS, have helped raise the bar for evolution education. I personally take pride in the fact that the student who gave me such a hard time about evolution – twice – recently wrote to me as he was completing medical school, to let me know that he came to accept evolution and appreciated me for never giving up on him. Aw, shucks!