The current decline in scientific competitiveness hasn't been reached overnight, and won't be turned around overnight. With that in mind, it's worth considering which way the trend is going. The level of science education received by high school students is a signal that points towards a continued decrease in our competitiveness.

HOW THE STUDY WAS DONE

Between March 5 and May 1, 2007, 939 teachers participated in the study, either by mail or by completing an identical questionnaire online. Our overall response rate of 48% yielded a sample that may be generalized to the population of all public school teachers who taught a high school–level biology course in the 2006–2007 academic year, with all percentage estimates reported in this essay's tables and figures having a margin of error of no more than 3.2% at the 95% confidence level. Detailed discussion of the methods of the survey and assessments of non-response can be found in Text S1. Our results confirm wide variance in classroom instruction and indicate a clear need to focus not only on state and federal policy decisions, but on the everyday instruction in American classrooms.

EXPLAINING DIFFERENCES IN TEACHERS' EMPHASIS

Those teachers who stressed evolution by making it the unifying theme of their course spent more time on it. Overall, only 23% strongly agreed that evolution served as the unifying theme for their biology or life sciences courses; these teachers devoted 18.5 hours to evolution, 50% more class time than other teachers. When we asked whether an excellent biology course could exist without mentioning Darwin or evolutionary theory at all, 13% of teachers agreed or strongly agreed that such a course could exist.

Figure 2. High School Biology Teachers' Personal Beliefs Concerning Human Origins, Compared with a Representative Sample of the General Public, Spring 2007

Notably, we find that teachers' personal beliefs are linked to classroom instruction. The teachers who chose the “young earth” creationist position devoted 35% fewer class hours to evolution (9.6 hours) than all other teachers (14.7 hours).

TEACHER QUALIFICATIONS

The No Child Left Behind Act requires that all teachers of core subjects be “highly qualified.” Definitions of “highly qualified” vary by state, but most include demonstrated competence in the teacher's teaching assignment. Our data suggest that high school teachers who completed the largest number of college-level credits in biology and life science classes and whose coursework included at least one class in evolutionary biology devote substantially more class time to evolution than teachers with fewer credit hours. The best prepared teachers devote 60% more time to evolution than the least prepared.

	Had no class on evolution	Completed a course devoted to evolution
Up to 24 credits	10.2	11.9
25-40 credits	11.6	16.2
over 40 credits	12.6	16.2

Table S6. Hours devoted to human evolution and general evolution (combined), by
number of college-level biology credits and course devoted to evolution (N=909)

CONCLUSION

Our study suggests that requiring all teachers to complete a course in evolutionary biology would have a substantial impact on the emphasis on evolution and its centrality in high school biology courses. In the long run, the impact of such a change could have a more far reaching effect than the victories in courts and in state governments.

Knowing where we came from is essential to knowing where we're going to go in the future. While certainly more students now are being taught the current scientific consensus on where we came from than were taught this in past decades, the gap between what they need to know to remain competitive and what we're teaching them is growing ever wider. The increase in this knowledge gap points towards further decline in competitiveness.