Crossing the Threshold: Bringing Biological Variation to the Foreground

Batzli, Janet; Knight, Jennifer K.; Hartley, Laurel; Maskiewicz, April Cordero; Desy, Elizabeth A.

doi:10.1187/cbe.15-10-0221

Cited by 26 publications

(26 citation statements)

References 38 publications

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“…The outcome of mutations is random with respect to their selective value in a given environment, that is, the environment does not cause the specific mutations needed. While the presence of variation has been the focus of previous research, and is even argued to be a threshold concept by some (Ross et al, 2010;Batzli et al, 2016), we propose that the underlying difficulty lies not in understanding the presence of variation (which can be readily observed in many populations) but rather in understanding the underlying processes causing and changing the variation (e.g., random mutations and probabilistic selection). Thus, we propose that the real change in conception of natural selection occurs when learners grasp that novel variation arises due to random factors and not in response to an organism's need.…”

Section: Randomness and Probabilitymentioning

confidence: 89%

Conceptual Characterization of Threshold Concepts in Student Explanations of Evolution by Natural Selection and Effects of Item Context

Göransson

Orraryd

Fiedler

et al. 2020

LSE

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Evolutionary theory explains a wide range of biological phenomena. Proper understanding of evolutionary mechanisms such as natural selection is therefore an essential goal for biology education. Unfortunately, natural selection has time and again proven difficult to teach and learn, and students’ resulting understanding is often characterized by misconceptions. Previous research has often focused on the importance of certain key concepts such as variation, differential survival, and change in population. However, so-called threshold concepts (randomness, probability, spatial scale, and temporal scales) have also been suggested to be important for understanding of natural selection, but there is currently limited knowledge about how students use these concepts. We sought to address this lack of knowledge by collecting responses to three different natural selection items from 247 university students from Sweden and Germany. Content analysis (deductive and inductive coding) and subsequent statistical analysis of their responses showed that they overall use some spatial scale indicators, such as individuals and populations, but less often randomness or probability in their explanations. However, frequencies of use of threshold concepts were affected by the item context (e.g., the biological taxa and trait gain or loss). The results suggest that the impact of threshold concepts, especially randomness and probability, on natural selection understanding should be further explored.

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Section: Randomness and Probabilitymentioning

confidence: 89%

Conceptual Characterization of Threshold Concepts in Student Explanations of Evolution by Natural Selection and Effects of Item Context

Göransson

Orraryd

Fiedler

et al. 2020

LSE

View full text Add to dashboard Cite

show abstract

“…Ross et al (2010) have also proposed several biological concepts that they distinguish from being only biological concepts because they concern more fundamental and general aspects of natural science. Since the variation in populations depends on random mutations in the genes, another threshold concept might be randomness (Bazil et al 2016). However, we have chosen to treat genetic variation in connection with the origin of variation, which in turn is a random process.…”

Section: Threshold Concepts For Understanding the Principles And Key mentioning

confidence: 99%

Biological Principles and Threshold Concepts for Understanding Natural Selection

2017

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Modern evolutionary theory is both a central theory and an integrative framework of the life sciences. This is reflected in the common references to evolution in modern science education curricula and contexts. In fact, evolution is a core idea that is supposed to support biology learning by facilitating the organization of relevant knowledge. In addition, evolution can function as a pivotal link between concepts and highlight similarities in the complexity of biological concepts. However, empirical studies in many countries have for decades identified deficiencies in students' scientific understanding of evolution mainly focusing on natural selection. Clearly, there are major obstacles to learning natural selection, and we argue that to overcome them, it is essential to address explicitly the general abstract concepts that underlie the biological processes, e.g., randomness or probability. Hence, we propose a twodimensional framework for analyzing and structuring teaching of natural selection. The first-purely biological-dimension embraces the three main principles variation, heredity, and selection structured in nine key concepts that form the core idea of natural selection. The second dimension encompasses four so-called thresholds, i.e., general abstract and/or nonperceptual concepts: randomness, probability, spatial scales, and temporal scales. We claim that both of these dimensions must be continuously considered, in tandem, when teaching evolution in order to allow development of a meaningful understanding of the process. Further, we suggest that making the thresholds tangible with the aid of appropriate kinds of visualizations will facilitate grasping of the threshold concepts, and thus, help learners to overcome the difficulties in understanding the central theory of life. Sci & Educ (2017) 26:953-973 https://doi

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“…Experts can implicitly recognize the importance and contribution of variation to topics in biology and the implications for the design of experiments and data analysis. However, students have difficulty integrating the abstract concept of variation into their mental model of biology [ 1 ].…”

Section: Introductionmentioning

confidence: 99%

Development of the Biological Variation In Experimental Design And Analysis (BioVEDA) assessment

et al. 2020

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Variation is an important concept that underlies experimental design and data analysis. Incomplete understanding of variation can preclude students from designing experiments that adequately manage organismal and experimental variation, and from accurately conducting and interpreting statistical analyses of data. Because of the lack of assessment instruments that measure students’ ideas about variation in the context of biological investigations, we developed the Biological Variation in Experimental Design and Analysis (BioVEDA) assessment. Psychometric analyses indicate that BioVEDA assessment scores are reliable/precise. We provide evidence that the BioVEDA instrument can be used to evaluate students’ understanding of biological variation in the context of experimental design and analysis relative to other students and to their prior scores.

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Crossing the Threshold: Bringing Biological Variation to the Foreground

Abstract: This essay summarizes the authors’ study of, conversations about, and thought processes on threshold concepts. Using biological variation as an example, the authors demonstrate the utility of threshold concepts for curriculum development and research on student learning.

Cited by 26 publications

References 38 publications

Conceptual Characterization of Threshold Concepts in Student Explanations of Evolution by Natural Selection and Effects of Item Context

Conceptual Characterization of Threshold Concepts in Student Explanations of Evolution by Natural Selection and Effects of Item Context

Biological Principles and Threshold Concepts for Understanding Natural Selection

Development of the Biological Variation In Experimental Design And Analysis (BioVEDA) assessment

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