Prevalence and Persistence of Misconceptions in Tree Thinking

Abstract

Darwin described evolution as “descent with modification.” Descent, however, is not an explicit focus of most evolution instruction and often leaves deeply held misconceptions to dominate student understanding of common ancestry and species relatedness. Evolutionary trees are ways of visually depicting descent by illustrating the relationships between species and groups of species. The ability to properly interpret and use evolutionary trees has become known as “tree thinking.” We used a 20-question assessment to measure misconceptions in tree thinking and compare the proportion of students who hold these misconceptions in an introductory biology course with students in two higher-level courses including a senior level biology course. We found that misconceptions related to reading the graphic (reading the tips and node counting) were variably influenced across time with reading the tips decreasing and node counting increasing in prevalence. On the other hand, misconceptions related to the fundamental underpinnings of evolutionary theory (ladder thinking and similarity equals relatedness) proved resistant to change during a typical undergraduate study of biology. A possible new misconception relating to the length of the branches in an evolutionary tree is described. Understanding the prevalence and persistence of misconceptions informs educators as to which misconceptions should be targeted in their courses.

Understanding the tree of life: an overview of tree-reading skill frameworks

“…As tree-thinking is seen as an increasingly important part of biological literacy (Baum and Smith 2013;Thanukos 2009) it is important to note that students at all educational levels struggle in engaging with evolutionary trees (Catley et al 2012;Gregory 2008;Kummer et al 2016;Omland et al 2008). Different authors have called for the implementation of tree-thinking in school curricula in order to improve students' knowledge of macroevolution (e.g., Baum et al 2005;Catley 2006;Meir et al 2007;Sandvik 2008).…”

“…Relying on a single trait or a small number of characteristics is not seen as suitable to get a reliable estimate on the relative relationship of species (Gendron 2000). Different studies have shown that students struggle with understanding evolutionary trees and display a great variety of widespread learners' misconceptions (Baum et al 2005;Gregory 2008;Kummer et al 2016;Meir et al 2007;Omland et al 2008;Thanukos 2009).…”

Teleological pitfalls in reading evolutionary trees and ways to avoid them

“…By purposefully overcoming challenges, species become more complex and are therefore "more (highly) developed" than other species. Therefore, the notion of seeing the taxonomic system as an increasing order of complexity could be a consequence of teleological thinking as proposed by Kummer et al (2016). In the course of this work, we will lay out this idea in more detail.…”

“…Despite the relevance of tree-thinking, numerous studies show that students struggle with these kinds of representations and that working with evolutionary trees is an issue at all educational levels (Baum et al 2005;Blacquiere and Hoese 2016;Bokor et al 2014;Kummer et al 2016;Meir et al 2007). This can be explained, as numerous known factors can affect the difficulty of reading evolutionary trees.…”

“…As evolutionary trees are the most direct representation of macro-evolutionary processes and are used as hypotheses concerning the relative relatedness of species, they are an indispensable tool in the learning and communication about evolution (Baum et al 2005;Meisel 2010;Nehm and Kampourakis 2014). The concepts of reading and interpreting evolutionary trees are poorly understood by students of biology, similar to how they find it difficult to understand evolution (Baum et al 2005;Gregory 2008;Kummer et al 2016;Omland et al 2008).…”