Primary Grade Children’s Capacity to Understand Microevolution: The Power of Leveraging Their Fruitful Intuitions and Engagement in Scientific Practices

Abstract

We investigated second and third graders’ capacity to understand microevolution, given a learning progression leveraging intuitions to build more adequate explanations, problematizing core ideas within scientific practices, and in-depth study of a single domain (botany or animal behavior). The intervention was implemented in both researcher-taught summer school and regular school-year classrooms in two consecutive years, allowing refinement of instruction mid-course, as well as comparison of learning outcomes. A case study examined how the pedagogy functioned within a strategically selected segment of curriculum enactment. Analysis of pre- and post-instruction interviews, using mean scaled estimates and maximum learning progression levels, revealed significant conceptual advancements for all cohorts across both sites and years. After Year I, a majority of children in researcher-taught and regular classrooms could predict and explain the impact of traits’ differential survival advantage on next-generation shifts in relative frequency given particular environmental change. After Year II, the majority in each cohort formed normative predictions and explanations of population changes across multiple generations. This pattern reflects a basic understanding of microevolution, providing evidence of the capacity of primary grade children to understand abstract ideas and, more generally, to benefit from much more conceptually and epistemically ambitious curriculum than current science standards recommend.

Notes

¹ “Intentionally left blank” is in the NRC document, indicating the absence of a natural selection standard to achieve by the end of second grade.

² A separate article (Metz, Wilson, & Cardace, in preparation) and conference paper (Cardace, Metz, & Wilson, 2019) focus on the extensive qualitative and quantitative analyses entailed in the development of the learning progression model.

³ We excluded from the analysis of several children who missed the post-interview due to either having moved or extended absence during the interview period.

⁴ Given the number of items at the highest level of the learning progression, the instrument potentially underestimates children’s growth at the upper end of the model.

⁵ We framed the initial botany thought experiment on the basis of Cody and Overton’s (1996) study of rapid evolution of aster seed structure on islands off of the coast of British Columbia.

⁶ All student names are pseudonyms.

⁷ In addition to being a part of the top-end of the model, we did not drop the Fit dimension from this article, as issues of fit were always a key aspect of our conception of important ideas involved in students’ coming to understand microevolution, the design, and functioning of the curriculum, and the teachers’ ongoing assessment of student understanding.

⁸ We do not attribute these marginal differences in performance between incoming second and third graders’ pre-instruction scores to learning about natural selection that comes simply with age, but rather factors of maturation that could potentially impact their performance during the interview (e.g., possibly an increased capacity to stay focused on the task or capacity or to take emergent ideas as objects of thought).

⁹ In addition to lions and field crickets, other animals children could consider included poison dart frogs, siamang gibbons, meerkats, and elephants. In each case, a project-prepared text helped the children develop the domain expertise to take up the research poster prompts.

¹⁰ For some children, teachers just helped with spelling or correction of spelling. Other children needed help in recording their ideas.:

¹¹ In Year II, the Regular School Year second grade participants were all new to the project, as no first graders participated. Regular School Year third grade classes included both students new to the project and “returners” who had participated as second graders, studying the other curriculum module. Both summer school classes combined second and third graders.

¹² There was a considerable gap for all returners between their post-instruction interview at the end of the first cycle and pre-instruction interview before the second, albeit larger for the Summer School cohort. Since the Regular School Year teachers implemented their first module in the spring and their second module in the fall of the next academic year, there was approximately a 3.5-month gap between the first cycle post-instruction interview and second cycle pre-instruction interview. There was a 10-month gap between post-instruction interviews in the first year of the Summer School and pre-instruction interviews for the second year.

¹³ Obviously, we would not expect a large number of students to test at the very top of the scale.

Additional information

Funding

This work was supported by the National Science Foundation [0814821].