Students’ views of biological evolution: looking at the literature

There is little doubt that biological evolution, or ‘evolution’ for brevity, has fascinated humans since the development of our ideas about science. Testament to this is the large number of studies that investigate the gulf between the scientific understanding and the general public’s views about evolution (e.g. see Glaze & Goldston, 2015). In 1973, Dobzhansky famously argued that the process of biological evolution is fundamental to a complete understanding of biology. He argued that it provides a framework to understand past and future events in the living world and unifies the study of life on Earth.

Teaching evolution in schools

Evolution has, for over 100 years, been assigned the status of a scientific theory, that is, an idea with a convincing body of evidence, accumulated over time, which gives it support (Palmquist & Finley, 1997). That is not to say that the processes of evolution are fully understood, but there is no doubt within the scientific community that the theory provides the best explanation for how life becomes adapted to its environment.

There are, therefore, very good reasons why evolution should be taught in schools, and why we should be interested in how and what students think about it. With a greater emphasis on ideas about how science is carried out permeating curricula across the world, there is a strong case to say that scientifically literate citizens should understand and accept the theory of evolution as a well-supported aspect of science.

This is evermore important because, despite the efforts of international learned societies (e.g. The Inter Academy Panel, 2006) and others, there is inconsistency in the teaching of evolution in schools around the world (Alters and Nelson, 2002) with some countries and states banning its teaching altogether (Moore, 2002).

Reviewing the literature

The topic of evolution is large, even within the boundary of a focus on teaching and learning in schools. This literature review is therefore selective which, while this means it is limited in some ways, I hope provides teachers and teacher educators with a useful understanding of current thinking about what is known about schools students’ views about evolution and what this means for our wider understanding of Science in the curriculum.

This review draws on literature from a range of sources, the bulk of which are academic papers and books. However, to capture a more complete understanding of the current thinking, the review also includes information from websites, materials designed for teaching and publications for children. The review is focused on secondary school students’ thinking about evolution but does also include information about children in primary schools and undergraduate study. The review is divided into three sections addressing the following themes:

• Students’ ideas about the status of ‘scientific theories’
• Students’ ideas about biological evolution
• Implications for teaching and learning.

Students’ ideas about the status of ‘scientific theories’

There is a large body of research to show that students’ beliefs and ideas about science and their views of themselves as science learners are inconsistent with the goals of science (e.g. Driver, Leach, Millar & Scott, 1996). In particular, students often view science as a static, fact-laden discipline with scientists (often white males) working in isolation. In reality, the nature of science is such that it is a highly collaborative and dynamic discipline where ideas are constantly tested and refined.

Beyond students’ caricature of science, are the ideas they hold about ‘scientific theories’. More than merely an ‘idea’, the theory of evolution meets the criteria of a scientific theory because there is a wealth of evidence to support it, coming from, amongst other sources: palaeontolotgy, embryology, molecular biology, comparative anatomy and genomics. A theory, in the everyday sense of the word, does not match the scientific definition and can mean ‘merely an idea’. This causes conflict for students because: 1. They may not be aware that the term has multiple meanings in different situations and 2. They may not be aware of the evidence to support the theory or understand its complexity.

Catley, Leher and Reiser (2005, p.16) describe the difficulties in understanding the evidence supporting the theory of evolution stating that to understand it, one needs be to able to relate ‘the complex relations among micro processes of natural selection and random genetic variation, macro processes of geologic events and speciation, and their interactions – considering organisms and species as participants in ecologies distributed over space and time’ together in a coherent way. It goes without saying that this is a challenge.

The problem of understanding evolution is compounded through the ways that human brains think about ideas about origins. There is growing evidence from psychological studies that humans, and especially children, have a brain architecture which favours the development of what, Russell and McGuigan (2015) call ‘folk biology’. This manifests itself in different ways but includes essentialist views of living things (i.e. all individuals of a species are identical) (Coley & Muratore, 2012; Gelman & Rhodes, 2012) and a teleological view of how change occurs (that is, there is purpose in evolution – the idea of ‘design’). This second point is well reported in children (and some adults) with the view that living things change because they need to or want to being revealed through a range of research (e.g. Kelleman, 1999).

Students’ ideas about biological evolution and natural selection

Much of the research into students’ thinking about evolution has come from the US. This is unsurprising because of the historical lack of acceptance of biological evolution within the US population. However, many of the findings of this research show similar patterns across the world. Drawing on the work of Borgerding, Deniz  and Anderson (2017), four key aspects affecting how students view evolution emerge from the literature, namely: acceptance and understanding of evolution, understanding of the nature of science (NOS), thinking around the nature of knowledge (epistemology), and the relationship between science and worldviews.

Understanding and acceptance of evolution

In general, students’ understanding about evolution is poor, with most having a limited understanding, much of which is focused solely on knowledge for public examination (Nehm & Schonfeld, 2007). Most students in both the US and Europe can state that species change through time and become extinct, with most also explaining that the Earth is billions of years old (Moore, et al., 2006).

However, students recall this information in a ‘surface way’ lacking deep and proper understanding. As Borgerding, Deniz  and Anderson (2017) document: many students hold Lamarkian views of evolution, seeing evolution as being purpose driven and happening within the lifetime of individuals. Others struggle to comprehend geological time periods, while a large proportion of students do not properly understand the origin of new traits or the role of variation in evolution. In addition, as stated above, students have been shown to have misconceptions surrounding the nature and strength of evidence for evolution and what this means in terms of the status of evolution as a ‘scientific theory’.

Additionally, evidence exists that students’ views are very resistant to change, especially change through schooling. This can be explained in a number of ways. There is emerging evidence that much of the teaching of evolution in schools is often done poorly, and especially in its relation to learning about the NOS. There are a number of reasons to explain this, including curriculum time pressures, pressure from external agencies and how the ideas of evolution are conceptualized in curricula (Goldstone & Kyzer, 2009). On top of this, in some countries, and especially the US (although there is growing pressure in parts of Europe), there is the additional issue of attempts by external (and sometimes internal) agencies to encourage a broader exploration of explanations about the diversityThe recognition of individual differences in terms of race, ethnicity, gender, sexual orientation, socio-economic status, physical ability, religious beliefs and other differences of life to include intelligent design and creationist views (Berkman & Plutzer, 2011; Bowman, 2008).

This has been shown to be particularly powerful for students in secondary school, where exposure to alternative explanations (within the Science classroom) can severely hinder a proper understanding of evolution (Kim & Nehm, 2011; Moore, Brooks & Cotner, 2011). There is also evidence showing that the approaches taken by teachers to support student learning about evolution are often ineffective. The drivers for these problems come from teachers feeling ill prepared from their teacher training experiences (Veal & Kubasko, 2003) and a lack of confidence which can lead to teachers quickly covering curriculum material without allowing time for more indepth analysis (Verhey, 2005). In addition, there are problems brought about through teachers not wanting to engage with the topic because they feel it may hurt the feelings of their students (Goldston & Kyzer, 2009).

The evidence on the link between understanding about, and acceptance of evolution is mixed. Some studies reveal no relationship (Sinatra, Southernland, McConaughy & Demaster, 2003), some show weak relationships (Deniz, Donnelly & Yilmaz, 2008) and others indicate stronger relationships (Rice & Kaya, 2012). What does seem clear is that the more instruction and teaching students receive about evolution, the greater their understanding of the processes of evolution (e.g. natural selection and genetics) and, in some cases, their acceptance of the theory. For example, undergraduates studying biology courses are more likely to accept evolution than those following other programmes (Nadelson & Sinatra, 2009; Smith, 2010).

Studies continue to show that changing beliefs and worldviews about topics like evolution is hard, with students’ alternative explanations and ideas being resistant to change (Yasri & Mancy , 2014). While it is perhaps not surprising that greater instruction leads to greater understanding, there is clearly the need for a re-evaluation of how and when evolution is taught in schools. In the UK, we should be encouraged by the arrival of the need to teach evolutionary theory in primary school (Harlen & Qualter, 2014) but this is only the beginning. It may well be time to argue for a more integrated approach to teaching evolution with the ideas embedded in the curriculum, rather than seen as an additional ‘topic’.

Understanding of the nature of science (NOS)

There is a clear relationship between students’ understanding and acceptance of evolution and the clarity of their thinking about the NOS (Akyol, Tekkaya, Sungur & Traynor, 2012). A key driver of this is that students who are able to think logically and make connections between disparate ideas, are more likely to understand the complexities of evolutionary theory (Sinatra, et al., 2003). Sinatra et al. argue that an ‘open minded’ thinking disposition is important to nurture in students if one of the aims of science education is to develop critical thinkers. The benefits of such ‘cognitive flexibility’ have been identified by many authors (e.g. Athanasiou & Papdopoulou, 2012; Deniz & Donnelly, 2011) suggesting that this approach is something worth nurturing in school.

Thinking around the nature of knowledge (epistemology)

Epistemology is concerned with the ‘origin, nature, limits, methods, and justification of human knowledge’ (Hoffer, 2002, p.4). For some time, researchers have recognised that understanding students’ epistemological beliefs would shed light on how they think, access new information and ideas and learn (Hewson, 1985). For example, Abd-El-Khalick and Akerson (2004) have shown that students who hold a dualistic view of knowledge (i.e. ideas are either ‘right or wrong’) have difficulties in accepting the NOS and, hence, theories in science. Perry (1970) was the first to begin describing the different levels of epistemological sophistication that students hold, with most students holding fairly unsophisticated views. This hinders their cognitive development preventing students from being able to deeply understand scientific ideas and concepts, with many students having ‘surface’ ideas (Akerson & Buzzelli, 2007). This has been shown to cause difficulties with students’ acceptance and understanding of evolution (e.g. Deniz & Donnelly, 2011).

The relationship between science and world views

It is well established that students’ understanding and acceptance of evolution is linked to their worldview, particularly one which is religious (Moore & Cotner, 2009). As noted above, there is clear evidence that, as students move through their education (including university), their acceptance and understanding increases but views are very resistant to change. Students in school take up various different positions about their views of the scientific explanation of the diversity of life on Earth. In some cases, they may compartmentalize their knowledge (Gould 1997; Yasri & Mancy, 2014), some see their opposing views in conflict (Hokayem & BouJaoude, 2008) and in some cases there is a reconciliation (Dagher & BouJaoude, 1997). This matters, because if a deep understanding of evolution is needed to fully engage with biological thinking, then educators need to take into account positions that students might take and develop strategies which might address these. This should lead to alignment with appropriate scientific thinking, whilst respecting students’ views.

Implications and the future

Reading this review might suggest that the picture about how students view evolution is a gloomy one. They struggle to understand the status of scientific theories, they hold misconceptions about evolution and the evidence for evolution, they do not properly understand the nature of science and can hold worldviews which make understanding and accepting evolution a challenge. Yes, these findings are depressing when taken at face value, and perhaps more worrying, do not seem to be changing. However, more concerning is the ability that students have for taking a surface approach for their learning to pass public examinations. If it is the case that to understand biology properly means having a deep understanding of evolution, then something needs to be done to address this.

The scope of this review is such that there is not space to explore teaching and learning strategies that may support the development of this deeper understanding (see Appendix for some suggestions), but what does seem clear is that teachers should not allow students to ‘choose’ for themselves what to believe but should provide them with evidence that allows them to come to conclusions that support the scientific explanations provided by evolution (Brem et al. 2003). Not only will this approach support a proper understanding of evolution but also wider ideas about the NOS. As it stands at the moment, curricular programmes across secondary school in the UK present evolution as ‘topic’ within the Biology curriculum. This is, I think, problematic.

If we are to heed Dobzhansky’s view that evolution unifies biology, then we should move to a curriculum where evolution permeates everything that is learnt, rather like the way that particulate theory underpins the Chemistry curriculum. An approach like this might pave the way to allowing students proper access to biological thinking. The move to include the study of evolution at Key Stage 2 is a welcome step in the right direction, but at the moment, there seems little desire from the QCA or examination boards to alter the status quo.

Useful resources for teaching

The following is by no means an exhaustive list of materials that are useful in supporting students’ thinking about evolution, but have been shown to be useful. Most of these suggestions come from Russell and McGuigan (2015).

Books

• Anholt L (2006) Stone Girl Bone Girl: The Story of Mary Anning of Lyme Regis. London: Frances Lincoln Children’s Books.
• Carle E (1997) The tiny seed. London: Puffin.
• Darwin C (1859) On the Origin of Species by Means of Natural Selection (1st ed.). London: John Murray.
• Dawkins R (1976) The Selfish Gene. Oxford: Oxford University Press.
• Dawkins R (2009) The Greatest Show on Earth: The Evidence for Evolution. Free Press Transworld Publishers.
• Doyle P (2008) British Fossils. Shire publications.
• Edwards K & Rosen B (2000) From the beginning. Natural History Museum, London. HMSO (1984). British Fossils. Geological Museum.
• Fortey R (1997) Life. An unauthorised biography. London: HarperCollins.
• Gould SJ (2001) The book of life. New York: Norton & Company.
• Naiman N & McKean D (2003) Wolves in the walls. London: HarperCollins.
• Osborne R & Benton M (1996) The Viking Atlas of Evolution. New York: Viking.
• Sloan C (2005) How dinosaurs took flight: The fossils, the science, what we think we know, and the mysteries yet unsolved. National Geographic Children’s Books.
• Weiner J (1995) The beak of the finch: Evolution in real time. London: Vintage.
• Zimmer C (2014) At the Water’s Edge: Fish with Fingers, Whales with Legs. New York: Atria Books.

Online Resources

Museums resources

• Earth Science Collection at the University of Bristol
• Understanding Evolution from Berkeley University
• Natural History Museum Origins, Evolution and Futures
• The Learning Zone from the Oxford University Museum of Natural History

Teaching resources

• Biozone Evolution Resources
• Teaching Evolution for Primary Children
• National Science Teachers Association Evolution Resources
• Nuffield Foundation Evolution Resources
• Nuffield Foundation Evolution Activities
• The Science Teacher Evolution Teaching Resources

Additional web-based resources

• Tree of Life from the Wellcome Trust
• OneZoom Tree of Life Explorer
• Life on Earth from Harvard University with the University of Nebraska State Museum
• The Geologic Time Scale in Historical Perspective from the University of California Museum of Paleontology
• UK Fossils Network