Wallace in the Amazon: A Case for Teaching Taxonomy & Scientific Practices

Teaching the nature of science while also teaching biological content has always been challenging (McComas, 2015). However, the task has renewed importance with the emphasis on scientific practices and crosscutting concepts in the new Next Generation Science Standards (NGSS) in the US (NGSS Lead States, 2013) and with similar goals in reform documents internationally (Brasil, 2000; Brasil, 2013; São Paulo, 2008; Hodson, 2008; OECD, 2023). Here, we present one such lesson on phylogenetic classification. It contextualizes active learning (inquiry) on taxonomy in a concrete historical context, fostering an understanding of how science works in an authentic case.

Our case follows the work of Alfred Russel Wallace (1823–1913), famous among biologists for discovering, in parallel with Charles Darwin (1809–1882), the concept of evolution by natural selection. This case, however, focuses on the young Wallace, who voyaged to the Amazon in the late 1840s to collect natural history specimens. Wallace observed the fauna, flora, geology, climate, and native culture. He recounted his experiences in A Narrative of Travels on the Amazon and Rio Negro (Wallace, 1889) in the same literary tradition as Darwin’s well-known Voyage of the Beagle. Wallace also took particular interest in the palm trees and their role in local cultures. He summarized his observations in Palm Trees of the Amazon and Their Uses (Wallace, 1853). Wallace’s scientific practices in documenting the various species and classifying them form the framework of our case, described fully below.

Several educational contexts support the consideration of historical cases for teaching the nature of science, scientific practices, and crosscutting concepts about science as a human and cultural endeavor (Allchin, 2024a). First, substantial evidence from educational research and psychological learning theory supports using case studies—or concrete, complex, contextualized examples—as vehicles for learning. By situating the concepts in real-world examples, case studies help students appreciate the relevance of the knowledge and thus help them build lasting cognitive links to concepts they already know (Prestes & Caldeira, 2009). Case study learning is now widely familiar in law, medicine, nursing, and other professional settings and is becoming more frequent in science education (Allchin, 2013a; Camill, 2006; Dinan, 2005; Fawcett & Fawcett, 2011; Herreid, 2007). Second, narratives (or stories), by using a human and social context, foster student motivation and, later, retention of content knowledge (Herreid, 2007; Stinner, McMillan, Metz, Jilek, & Klassen, 2003; Yadav & Beckerman, 2009). Engagement and practice with problem-solving in cases can also enhance critical thinking skills (Dori, Tal, & Tsaushu, 2003; Herreid, Schiller & Herreid 2012; Stake, 1983).

Our approach used history as a guide (Allchin, 2024b). Historical narratives can vividly convey “science-in-the-making” or glimpses of authentic scientific practices. They also help render science’s human, social, cultural, economic, and other contexts in ways not possible in exclusively student-based inquiry. Most importantly, perhaps, historical episodes can form a structure for organizing student inquiry (Allchin, 2012, 2014; Hagen, Allchin & Singer, 1996; Norris, Guilbert, Smith, Hakimelahi, & Phillips, 2005; Rudge & Howe, 2009). History thus provides a valuable method for integrating scientific content and scientific practices (via inquiry), along with reflection on the cultural and human dimensions of the nature of science (nicely exemplified in this journal by cases by Howe, 2007, 2009, and others in this special issue).

Adopting this perspective, we present a teaching and learning sequence (Méheut & Psillos, 2004) that uses the historical case of Wallace and palm trees to teach about taxonomy and phylogeny, as well as aspects of data analysis and communicating of scientific ideas (through informative and accurate visualizations).

Wallace journeyed to the Amazon region in 1848, well before going to Malaysia, where he developed the idea of natural selection (Fichman, 2004). Inspired by contemporary travel narratives of the period, such as those written by Darwin and Alexander von Humboldt (1769–1859), Wallace decided to study the diversity of organisms in the tropics. However, the 1847 book of William Henry Edwards (1822–1909) led him to choose Pará and Amazon rather than another part of the tropics. Edward’s narrative provided decisive reasons for his choice, such as the vegetation’s grandeur, the people’s kindness and hospitality, and the low cost of living and traveling. Edward Doubleday (1811–1849), an entomologist at the British Museum, assured Wallace that the journey could be successfully financed by selling rare and new species because “all that northern Brazil was very little known.” Wallace was convinced this was the place “to go to if there was any chance of paying our expenses by the sale of our duplicate collections” (Wallace, 1905, p. 264).

In the beginning, Wallace was accompanied in the Amazon by Henry Walter Bates (1825–1892), another English naturalist and friend who became chiefly known later for his studies on the coloration patterns of butterflies. These studies gave rise to a concept later called “Batesian mimicry” (Bates, 1863). Wallace and Bates met in Leicester, England, around 1845. At the time, Wallace taught drawing and arithmetic at a local school. With Bates, Wallace extended his avid interest in plants to include insects and became a professional specimen collector. While collecting beetles and butterflies, he learned the specialized techniques for fixing, preserving, and storing them.

Other factors besides the inspiration from literature contributed to the two young friends’ decision to travel to a tropical region such as the Amazon. With no job security but an interest in studying animal and plant diversity, they glimpsed the possibility of subsidizing the trip by selling exotic specimens collected in that region. Both were already familiar with the practice of collecting specimens in England.

For the first two years, between 1848 and 1850, Wallace and Bates worked together, collecting different species of organisms in the lower Amazon and Tocantins Rivers region. Through a London agent, Samuel Stevens, the two “enterprising and deserving young men” sent two parcels of insects from different orders, “containing about 7,000 specimens in very fine condition, and a vast number of novelties, besides other very rare species” (Wallace, 1849, p. 74). After receiving the parcels, Stevens announced them in the Annals and Magazine of Natural History.

In early 1850, the two naturalists decided to work separately to expand the collection of species from different regions. Bates explored the Rio Solimões while Wallace chose to follow the Rio Negro, the largest tributary of the Amazon River (Brooks, 1984; Marchant, & Wallace, 1916). In the four years he spent in the region, Wallace observed, described, designed, and collected specimens of different types of animals and plants. He also investigated the morphology, distribution, and habits of a wide variety of species, among them palm trees, butterflies, beetles, monkeys, and different types of birds and fishes. Through his studies, Wallace emerged as an expert observer, collector, and researcher (Carmo, 2011).

Wallace returned to England in July 1852. Due to problems with customs, all the material he collected alone on the Negro River remained accumulated in the port of Belém. He loaded them on the ship with him, but once at sea, the boat caught fire and burned completely. Wallace and the crew escaped alive, but he lost two years’ worth of valuable collections. He had time only to carry his diary and some drawings of fish and palm trees to the lifeboat (Fichman, 2004; Marchant, & Wallace, 1916; Wallace, 1905. Fish drawings were only recently published in a remarkable edition by the Brazilian biologist Wallace, 2002). Thus, only the two shipments of specimens collected with Bates, sent in July 1848 and July 1849, arrived in England.

In the months after his return to England, Wallace devoted himself to publishing his Amazonian studies. To achieve this, he had letters from Amazon sent to his family and friends, a diary saved from the ship’s fire, and thorough memories of his experience. Six articles were published by the Zoological Society of London, the Entomological Society of London, and the Royal Geographical Society. Wallace discussed the habits, geographical distribution, and morphological characteristics of butterflies, fishes, and monkeys along the banks of Amazonian rivers. He also published two further books in 1853. One contained a description of his journey, A Narrative of Travels on the Amazon and Rio Negro, with an account of the native tribes, and observations on the climate, geology, and natural history of the Amazon valley (a second edition appeared in 1889). Today, because of this publication, we know about the Amazon during this period, from its physical geography and geology to the habits of the Indigenous tribes that Wallace encountered (Camerine, 1996).

Wallace’s travel narrative also provides accurate information about his native collaborators, who assisted in his studies and collections. As with many other foreign naturalists who visited Brazil in the nineteenth century, Wallace relied significantly on contributions from local cultures in developing “his” scientific knowledge of the Amazon. Wallace also used “networks formed by interaction with the communities living in the areas visited.” The locals facilitated the fieldwork for foreign scholars and even made it possible (Moreira, 2002, p 41; Martins, 2011).

The local communities were composed of Portuguese Colonials and their African slaves, as well as members of different Indigenous tribes and “caboclos” (children of white and Indians). Contact with them was essential for logistical support and infrastructure and providing food, housing, transportation, and other material resources. They also worked as guides, carriers, rowers, interpreters, and assistants, contacting Indigenous groups and teaching their languages. From the point of view of exchange of knowledge, it is essential to emphasize that local communities provided their traditional knowledge on various practices, such as hunting, fishing, and crops; conservation of collected materials; protection against harmful insects; animals and plants as food sources; species identity and geographical distribution of different plants and animals and so on. Thus, the native knowledge of these residents, with their long forest experience, was reorganized and incorporated into European scientific knowledge (Moreira, 2002, p. 42).

Wallace’s interest in palm trees also led him to write a small book, Palm Trees of the Amazon and Their Uses, which included the drawings saved from the fire and other information he remembered. The book brings together original drawings of forty-eight species of palms found along the Rio Negro and the Amazon River between the years 1848 and 1852. In addition to botanical details and the geographical distribution of different species of palms, Wallace also described the many uses of their leaves, fruits, seeds, stems, and roots by local Indigenous and settler populations (Wallace, 1853).

For students in Brazil, where this case was developed, the occurrence of palms in urban gardens and natural landscapes is familiar. Students in southern states in the US can also readily appreciate Wallace’s work, although applied to different palm species. In other regions, one can easily highlight the analogous role of local tree species and their historical uses by native cultures, such as wood for building; bark from birches; edible acorns and nuts from oaks, walnuts, chestnuts, buckeyes, and pines; fruits; fuel; medicines; and so forth.

It is worth remembering that, on this occasion, Wallace’s goal was to know the variety of species in the region by documenting observations and collecting specimens, the usual scientific procedures to the present day (Prestes et al., 2000). Only later, when he became interested in explaining the origin of biological diversity in Malaysia, did he develop the idea of evolution by natural selection (see Friedman, 2010, for another historical inquiry activity).

From the 1980s onward, a community of researchers dedicated to the interface between the History of Science and science teaching emerged. Empirical research carried out in Brazil in 2012 showed that, although there was already such a large community in the country, few studies focused on investigating classroom practices, especially in Biology (Teixeira, 2008).

Considering the emotional dimension of motivation is integral to effective learning (Palmer, 2005; Meyer & Turner, 2006; Pintrich & Schunk, 1996; Ryan & Deci, 2000), we carried out research on whether introducing episodes of the History of Biology—according to a contextual approach, avoiding legendary anecdotes, pseudo-history, and historiographical distortions that usually circulate in textbooks—could contribute to motivating students in learning biology content.

The research involved building, validating, iterating, and evaluating a Teaching and Learning Sequence (TLS). Following Martine Méheut and Dimitris Psillos (2004), the TLS was used as a research tool and innovative teaching proposal to manage problems related to specific learning topics. The guiding biological theme of the TLS is phylogeny. This scientific conceptual content was organized through the historical framework of Wallace’s case, using his original descriptions and drawings of thirteen of the forty-eight palm tree species he studied. The TLS aims to address four different learning objectives so that students can acquire scientific and historical knowledge, develop research skills, and understand how science works (Allchin, 2024b).

The TLS targeted grade 11 students, ages 16–17, and was designed for eight successive class periods of 50 minutes each. It was applied at a public school in the city of São Paulo in 2013, involving sixty students. All the required teaching materials (lecture notes, images, student handouts, and guides) are available online at https://shipseducation.net/modules/biol/palms.htm. The high school teacher conducted classes, and the researcher observed the participants along all TLS, recording (audio and video) all classes and making personal notes.

On the first day, students are introduced to Wallace and his voyage through an illustrated lecture (as described above). Students also map his travels (Figure 1).

On the second day, students take a field trip on campus to observe palm trees, as Wallace did, draw them, and label the key parts of the plant (Figure 2).

The next day, they compare their own work with Wallace’s and modern descriptions and consider, for example, the relative roles of diagrams and photos (Figure 3).

On Day 4, students build simple taxonomic models of the palms based on their informal impressions of similarities and differences. The following day, they used dichotomous trees to identify and classify the palms based on contemporary classifications. Day 6 is a more conventional lecture on evolution and the principles of phylogeny. This leads to 2 days in which the students construct a phylogenetic matrix on a computer spreadsheet and then use the results to construct a phylogeny (Figure 4), which they compare with their earlier classifications based on more traditional methods. The unit ends with a short historical reflection on following Wallace’s footsteps and an explicit review and commentary on scientific practices.

The specific historical and scientific content of the classes are

• Wallace’s work on the palm trees of the Amazon in the context of scientific expeditions in nineteenth-century Brazil;

• observation and description of palm trees;

• use of dichotomous keys for the identification of species;

• taxonomy, addressing taxonomic criteria by comparing classification based solely on similarities and differences and classification based on evolutionary relationships; and

• principles and procedures for phylogenetic classification and the construction of phylogenetic trees from some of the palm trees studied by Wallace.

The specific research skills and aspects of how science works are: funding research, planning logistics of field expeditions, collecting and preserving specimens, collaborating with other experts, reading maps and plotting data, observing and describing distinctions, recording visual observations (drawing), comparing and assessing data, building simple models, applying existing knowledge to interpret observations, and developing background knowledge.

Table 1, “Summary of daily learning objectives,” details how the teaching proposals and their learning objectives were oriented. The historical case, along with parallel student activities, enabled the integration of scientific concepts with scientific practices and crosscutting concepts (summarized in Table 2, according to the framework of the NGSS).

To observe students’ motivation, we used the protocol developed by Hsiao-Lin Tuan and collaborators (2005). It was chosen because it was specially created to understand students’ motivation for science learning through six categories (self-efficacy, active learning strategies, science learning value, performance goal, achievement goal, and learning environment stimulation). The questionnaire was initially administered in 2004 to 1407 high school students in Taiwan. It was applied at two moments of our TLS: before the first and at the end of the eighth and final classes. The questionnaire has a limitation, already indicated by its authors (Tuan et al., 2005, p. 640), and confirmed by us that, as it is long, it is suitable only for high school, requiring adaptation if applied to initial/fundamental teaching segments.

The activity produced several positive effects. Students were very encouraged by the learning environment. About 70% of the total sixty students agreed that they felt motivated to participate in the biology class because different teaching strategies were used. Students were highly involved in almost all activities. The participation of students during classes was significant. Only in one class was it observed that there was slightly less involvement in identifying palm trees with dichotomous keys (class 5). The lack of interest seems to have been due to the difficulty of the activity that required prior basic botanic knowledge, which had not been previously taught, about the terminology of plant structures, such as bract, trunk, and infructescence, among others.

The active participation of students during classes was significant. They asked a lot about Wallace’s collection practices, comparing what he did in the nineteenth century with the legal restrictions in Brazil today on gathering organisms in the wild. The students were curious about the practical aspects of Wallace’s travel by boat and the long time it took to reach the Amazon. They discussed traveling through the rivers of the region. When informed of the number of specimens collected, for example, more than 1,300 species of insects, one student asked whether they had helpers during the trip—reflecting her perception that one cannot do science alone.

The transcription below shows how they drew comparisons about how the work of science was carried out in the nineteenth century and today. They also proved to be perceptive when it came to collecting specimens and motivated to research by themselves:

Students expressed great admiration for Wallace’s way of life and scientific achievements compared with Charles Darwin’s highly privileged economic status. Below is the interaction between the teacher and students on the social, cultural, and financial aspects of science.

The students were very impressed with the drawings created by Wallace. When carrying out the various TLS activities, they preferred to use these drawings rather than the modern photos (Figure 2).

In class 2, “Observing Like a Naturalist,” students enjoyed drawing palm trees in the school’s surrounding area. They felt like naturalist researchers and identified with Wallace. Doing an activity similar to Wallace’s increased students’ self-esteem.

This article reports a contextualized class sequence with the historical case of Wallace’s nineteenth-century journey in the Amazon and his studies of palm trees. The experience produced good ways to motivate the learning of biological and historical content, lead students to scientific practices, and discuss aspects of the nature of science. The case illustrates more generally how drawing on investigations of nature from the past can contribute to a more complete science education, as profiled in new curriculum standards.

The authors would like to thank Douglas Allchin for his collaboration in reviewing the manuscript for ABT readers and anonymous reviewers for their suggestions for improving the work.