Is being familiar with biodiversity related to reasoning about ecology?

Abstract

Many science educators believe that student recognition of biodiversity is an important precursor to discovering patterns and understanding processes that define and shape ecological systems. We investigated (1) the total number, taxonomic categories, specificity, and diversity of backyard organisms that middle (MS) and high school (HS) students and teachers named, (2) how the number, specificity, and diversity of organisms that students and teachers named related to their overall performance on an ecology learning progression assessment, and (3) the types of information students used to sort and group organisms. Our sample population included 264 MS students, 374 HS students, and 108 teachers in five U.S. states (California, Colorado, Maryland, Michigan, and New York). We found that students were more likely to name vertebrates than plants or microorganisms, while teachers were more likely to name vertebrate and plants than microorganisms. Teachers named a higher total number (richness) and diversity of organisms and named more organisms in specific (e.g., bull snake) than general taxonomic categories (e.g., snake) than did students. Individual performance on the ecology learning progression assessment was positively correlated to the total number (richness), diversity, and specificity of organisms that students and teachers could name. The types of information students invoked to group organisms together varied by question context. Most students invoked information related to form/outward traits, habitat, function (e.g., decomposer), and taxa (e.g., fungi, plant, animal). Notably, some students invoked ideas about evolutionary relationships among organisms. This work corroborates previous findings about student familiarity with biodiversity and provides preliminary evidence that familiarity with local biodiversity is linked to reasoning about ecology.

Introduction

Biodiversity is a multifaceted term that is commonly used to describe the variety of life in the natural world (Western ). Ecologists reason about biodiversity at many scales, from gene to species to community to ecosystem. Further, ecologists are concerned with the causes and consequences of biodiversity. The composition of plants, animals, and microbes within an area affects ecosystem structure and function and, therefore, the ecosystem services (e.g., disease resistance, pollination, and production) upon which humans depend (Isbell et al. ). As scientists and educators, we note the importance of understanding biodiversity in the context of these ecological processes, especially around global issues of climate change, pollution, and sustainability. Additionally, accelerating environmental degradation and species loss has prompted biologists to emphasize the importance of encouraging learning experiences related to biodiversity (Dor‐Haim et al. , Kilinc et al. ). Developing the ability to recognize and name organisms is foundational to understanding complex mechanisms that occur in nature.

We created a grade 6–12 learning progression for community ecology using iterative cycles of assessment and analysis (described in Methods). We developed assessment items about community ecology (i.e., biotic interactions, biotic–abiotic interactions, dispersal) to produce and refine our learning progression. Our assessments also included items related to student recognition of biodiversity and related to how students group organisms. This paper explores these additional items (Fig. ). We investigated (1) the total number, taxonomic categories, specificity, and diversity of backyard organisms that students and teachers could name, (2) how the number, specificity, and diversity of organisms named by individual students and teachers related to his or her level on the learning progression, and (3) the types of information students used to group organisms. Our findings extend existing published research on student familiarity with and reasoning about biodiversity, and given our large and diverse sample, provide a snapshot of how some U.S. students think about this topic. Our work can be used to understand current shortfalls in biodiversity education and offer insights into improving student reasoning about biodiversity and ecological systems.

Research about recalling and naming biodiversity

Research conducted abroad and with younger students has shown that lived experiences, children's literature, textbooks, television entertainment, and educational nature films are all potential influences on student knowledge of biodiversity (Balmford et al. , Huxham et al. , Link‐Pérez et al. , Dove ). The following literature about middle (MS) and high school (HS) student naming of biodiversity reveals patterns and gaps in student knowledge. For example, students of all levels were more likely to notice and be interested in animals when compared to plants and microorganisms because animals were seen as more charismatic, which has been termed “plant blindness” (Randler ). Students were more likely to name endemic, exotic, pet, and domestic/farmed animals (Patrick et al. ) and were more able to identify mammals and birds than other organismal groups (Yen et al. ). Additionally, students and instructors scored poorly on tests requiring them to identify native organisms (Bebbington , Palmberg et al. ), and this skill appears to be declining in recent years (Francis , Braun et al. , Palmberg et al. ).

One possible reason students may not do well with identifying organisms is the trend to deemphasize coursework on natural history (Middendorf and Pohlad ). In the past several decades, we have seen decreases in the number of organismal biology courses offered at schools (Futuyma , Greene , Grant ). Instead, students learn ecology without the outdoor experiences that build connections to the organisms and places that are most familiar to them, contributing to a disconnect with nature that prevents establishing pro‐environmental attitudes (Kals et al. , Celis‐Diez et al. , Soga and Gaston ). Middendorf and Pohlad () assert that unless we can name species, we cannot understand or appreciate biodiversity. The complex problems and processes that we study are grounded in knowing the types of species that exist (Middendorf and Pohlad ).

Relating reasoning about ecological systems to recognizing organisms

We posit that students must first be able to recognize local biodiversity (i.e., name and group living organisms) before they can begin to reason about ecological systems and communities. This mimics the development of the field of ecology and its inception in the naturalist studies of scientists such as Darwin, Linneas, and Humbolt who explored and categorized the diversity of life across the planet (Farber , Hector and Hooper ). To our knowledge, no formal research has related familiarity with biodiversity to reasoning about ecology, though there have been assertions (Randler , Songer et al. , Scott et al. ). We have created a learning progression for community ecology (Appendix S1) to test those assertions. Thus, we are able to relate data we gathered about student familiarity with biodiversity to their proficiency on a learning progression assessment for community ecology to test those assertions.

Research about grouping of organisms based on relatedness, form, and function

One of the goals of biology education is to help students unify core concepts and ideas, such as relating organismal diversity to evolutionary processes (McGlynn ). Beyond naming, it is important that students understand mechanisms that allow for diversity, such as speciation and extinction, as a means of organizing and making sense of diversity on earth (Gibson and Hoefnagels ). Our current understanding of organismal diversity has evolved significantly since the conception of the two‐kingdom system and the subsequent five‐kingdom system introduced by Whittaker (). There is a growing body of literature that examines how students conceptualize relationships among different organisms. For example, when asked to group organisms together, students of all ages use superficial features, such as morphology, habitat, and movement as criteria for relatedness (Braund , , Kattmann , Burgoon and Duran , Cinici , Wyner and Doherty ). These habits remained even in college‐aged students (Trowbridge and Mintzes ). Many student responses to questions about relatedness were devoid of genetic evidence unless purposefully prompted by the instructor to think about evolution (Cooper et al. ). One study also showed that teachers had similar conceptions as their students about phylogeny and classification, which may be a potential reason why student understanding does not improve with additional years of schooling (Kılıç ).

Science educators hypothesized that students struggle with grouping organisms and discussing relatedness because of a lack of taxonomic literacy. For example, when students think of animals, they think primarily of vertebrate mammals (Trowbridge and Mintzes , Braund , Patrick and Tunnicliffe ). Students also have narrow definitions for vertebrate (i.e., having a full head and limbs) and invertebrate (i.e., flat, no limbs, and more amorphous), and as such, they commonly misclassify organisms such as snakes and fish (Braund , Burgoon and Duran , Cinici ). Additionally, their affinity to focus on morphology and locomotion results in a difficulty of discriminating animal groups, such as fish, birds, mammals, amphibians, and reptiles (Burgoon and Duran ). For example, Braund () and Burgoon and Duran () had students and teachers classify penguins, which are birds, and noted that many of the students and teachers placed them as mammals (because they do not fly) or fish (because of their ability to swim). Deconstructing how students think about biodiversity—their conceptions, misconceptions, or incomplete knowledge—is vital to helping our students have a more sophisticated understanding of biodiversity and its importance.

This paper addresses several research questions:

1. What types of and how many backyard organisms do MS and HS students and teachers name?
2. Does ability to name organisms relate to student and teacher performance on an ecology learning progression assessment?
3. What types of information do MS and HS students use to group organisms?

Methods

Sample population

We explored U.S. MS and HS student and teacher knowledge of biodiversity through several assessment items. We administered written assessments to MS students (grades 5–8, n = 264), HS students (grades 9–12, n = 374), and teachers (n = 108) in five states (California, Colorado, Michigan, Maryland, and New York). Teachers who administered the assessments were all affiliated with a National Science Foundation Long‐Term Ecological Research (LTER) site. In most instances, assessments were administered online using classroom computers. There was no time limit for taking the assessment other than limits set by how long the teacher allotted students, usually a single class period. The written assessments were administered in 2011–2012 after the students participated in a two week long teaching unit about the biodiversity of a stream food web (full teaching unit can be requested from the authors and found at http://www.pathwaysproject.kbs.msu.edu/?page_id=53).

Question and analysis for naming question

To explore student and teacher naming of biodiversity, we asked individuals to name organisms that they see in their backyard/neighborhood (Fig. ). Using 10% of the total responses, we generated 35 categories (Appendix S2) based on the taxonomic group (e.g., plant, mammal, bird) and specificity (e.g., bird vs. American Robin) of the organism. Categories were mutually exclusive, meaning that organisms cannot be placed into more than one category. The responses were coded using NVivo 10 (NVivo ). Responses were auto‐coded by NVivo's text analysis function using our predetermined list of words, and rarer responses were coded manually. After the completion of coding, a matrix was created in NVivo to see the number of organisms listed under a category for each individual (student or teacher). From this, we calculated richness (total number of organisms) and specificity (number of specific organisms named when compared to general organisms) of the organisms named by each individual (Table ).

Example of coding scheme used in one exemplar student response

Naming list	Placed into categories	Richness	Specificity	Simpson's diversity
Killdeer, Rabbit, Finch, Robin, Fox, Prairie dog, Mosquito, Grasshopper, Cricket, Ant, Funnel Spider, Cottonwood, Plum, Cherry, Peach, Rye grass, Elephant grass, Maple, Kentucky blue grass	Birds (Specific)—Killdeer, Finch, Robin Mammals (Specific, Wild)—Rabbit, Fox, Prairie Dog Invertebrates (Non‐specific)—Mosquito, Grasshopper, Cricket, Ant Invertebrates (Specific)—Funnel Spider Trees (Specific)—Cottonwood, Plum, Cherry, Peach, Maple Grass (Specific)—Rye, Elephant, Kentucky Blue	19	15 Specific 4 General	5.23 (treating each category as an organismal unit)

To capture the variation and distribution of the types of organisms that students and teachers identified, we calculated an inverse Simpson's diversity index for the collection of organisms named by students and teachers. Simpson's diversity is a popular index in the field of ecology (Simpson ). Inverse Simpson's diversity index allowed for an easier interpretation; if all categories had the same number of individuals, the diversity would equal the number of categories (Möckel et al. ). To calculate the diversity score, we treated each category as the organismal unit (Table ).

To explore the richness, diversity, and specificity in organisms named by grade band (MS, HS, teacher), we used a Kruskal–Wallis one‐way ANOVA and pairwise Wilcoxon rank sum post hoc tests to determine whether there were differences between different grade bands in general and when conducting pairwise comparisons. We chose the Kruskal–Wallis and Wilcoxon tests because our data were not normally distributed.

Relating learning progression to richness, diversity, and specificity

This study of student naming of biodiversity was part of a larger project to create a grade 6–12 learning progression for community ecology (L. M. Hartley et al., unpublished manuscript). This learning progression included written and interview assessments, a framework describing the progression of student thinking from grades 6 through 12, and an associated teaching unit (see http://www.pathwaysproject.kbs.msu.edu/?page_id=53 for assessments and teaching unit; see Appendix S1 for synopsis of the framework). Assessments asked students to describe ecological community structure, function, and/or change over time. Assessment items were focused singly or integratively on three phenomena viewed by ecologists as key drivers of community assembly: biotic interactions, abiotic resources and conditions, and dispersal of organisms within and among communities. This progression was developed over five iterative cycles (approximately every academic year) of assessment development, analysis, and framework revision. Using assessments from the 2011–2012 academic year, we scored student and teacher answers to individual item units and used item response theory to assign a learning progression proficiency score, namely expected a posteriori ability estimate score (hereby referred to as EAP). The naming and grouping items analyzed here were not included in the calculation of the proficiency score but were administered at the same time as the questions used to calculate proficiency, which is a continuous measure.

After calculating richness, specificity, and diversity scores, we used linear regression to determine whether richness, specificity, and/or diversity were correlated to EAP. We recognized that there were other likely variables that would predict EAP, such as how the instructor implemented the unit or students’ personal interest. However, we did not have quantifiable data related to other candidate variables. We standardized all variables using z‐transformations. We created several hypothesized models and chose the best model, represented by the lowest Akaike information criterion (AIC) value. We did not include the grouping items into the hypothesized models because students’ groupings were context dependent, and teachers did not complete the grouping items.

Questions and analysis methods for grouping items

To understand how students grouped organisms and the criteria that they used in their answers, we asked three questions (Fig. ). Two of our questions gave students a related group of three organisms and asked them, from a choice of two different organisms, to identify the one that they would add to the group. They were then asked why they made their decision and asked about how they would define “closely related.” Our third item presented students with three predetermined groups. From these groups, students were asked to explain why they believe the organisms were grouped in that manner (Fig. ).

We examined a sample of 50 student responses to ascertain what criteria students used to explain organism relatedness. We sorted the coded responses into five categories based on the most common criteria students invoked: form or outward traits (e.g., all have fins), habitat (e.g., all live in water), function/process (e.g., all photosynthesize), taxonomy (e.g., these organisms are vertebrates), and/or evolutionary relationships (e.g., they share a more recent common ancestor; Table ). We differentiated taxonomy from evolution because students may be able to recognize traditional taxonomic groups (i.e., vertebrates, invertebrates, mammals, amphibians) without mentioning that all these organisms share common ancestry and diverged from ancient lineages. Though we had expected students to reason using physical traits due to the use of “traits” in the assessment, we noted a sizeable number of students referred to taxonomy and evolution, hence our inclusion of these categories. Responses could have more than one categorical type or none. Approximately 10% of the responses were coded by two researchers to ensure reliability. The teacher version of the assessment did not include grouping items, so we did not relate grouping ability of the teachers to their EAP score from the learning progression.

Descriptions and sample student responses for grouping items

Coding category	Description	Sample responses
Form	Student mentions that organisms are related because of similarity in looks	“One has feathers and the other is hard.” “It's green from the chloroplasts”
Habitat	Students mention that organisms are related because they live in similar areas	“They both live in water.” “Because they both live off the soil in the ground”
Process/Function	Students mention that organisms are related because they perform similar functions and can do similar actions	“It swims and breaths under water.” “Because fungi are decomposers not producers”
Phylogenetic group	Students mention that organisms are related because they come from similar groupings	“They both come from the same ‘family’, group.” “Because they are all in the plantae or plant kingdom”
Evolutionary relationship	Students mention that organisms are related because they have similar distant relatives or genetic material	“Come from common ancestry.” “That they have similar DNA makeup”

We were interested in identifying trends in the criteria students used to group organisms (i.e., If they used habitat in their response, what other types of criteria were they likely to use?). As such, we performed hierarchical cluster analysis, which used bootstrap analysis to identify significant clusters (Suzuki and Shimodaira ). We generated dendrograms for each question to look at how response types grouped.

Results

Naming biodiversity

In the “name as many organisms in your backyard” question, teachers named more organisms when compared to MS and HS students (Fig. ). Middle school and HS students named more vertebrate and invertebrate organisms than plants and microbes. Middle school and HS students did not significantly differ from one another in the number of invertebrates, plants, and microbes they named, but HS students on average named more vertebrate species (5.53 ± 0.28) than MS students (4.60 ± 0.31, P = 0.03). Teachers named significantly more plants (7.69 ± 0.67, P < 0.001), when compared to MS and HS students. Teachers also named a higher number of vertebrates (7.37 ± 0.82) than MS students (P = 0.001). Middle school (1.20 ± 0.11) and HS (1.23 ± 0.07) students named more microbes than teachers (0.83 ± 0.10, P = 0.006).

We noted similar trends when comparing diversity and specificity at different grade bands (Fig. ). While MS and HS students named a similar diversity of organisms in their backyards, teachers named a greater diversity (6.65 ± 0.21, P < 0.001). Additionally, teachers named more specific organisms (e.g., “Blue Jay” as opposed to “bird,” “Cicada” as opposed to “bug,” “Cottonmouth” as opposed to “snake”) when compared to MS and HS students (P < 0.001; Fig. ).

Naming as it relates to learning progression

Our regression analyses indicated that, in the best model, grade band, species richness, specificity, and species diversity correlated with EAP (Table ). High school students (P < 0.001) performed 0.252 logits higher and teachers (P < 0.001) performed 0.716 logits higher on LP proficiency when compared to MS students. Individuals whose richness scores were one unit higher had EAP that was higher by 0.203 logits (P < 0.001). Individuals whose diversity scores were one unit higher had an EAP that was higher by 0.123 logits (P < 0.001), and individuals whose specificity scores were one unit higher had an EAP that was higher by 0.069 logits (P = 0.030).

List of candidate models for regression analyses and ∆AIC values

Model	ΔAIC
EAP ~ Grade Band + Diversity + Specificity +Richness	0
EAP ~ Grade Band + Diversity + Richness	2.700
EAP ~ Grade Band + Specificity + Richness	11.438
EAP ~ Grade Band + Richness	13.772
EAP ~ Grade Band + Diversity + Specificity	31.428
EAP ~ Grade Band + Diversity	45.630
EAP ~ Grade Band + Specificity	67.017

Note

AIC, Akaike information criterion.

Grouping items

In our first two grouping items, we asked students to decide, of two organisms, which would best fit a predetermined group. In our third grouping question, we had three predetermined groups and asked students why these organisms were grouped in that manner. Responses were variable depending on the question, indicating that context mattered to student reasoning in this instance. Therefore, we separately present results for each grouping question.

Crayfish/bird item

When students were prompted to choose whether a bird or crayfish belonged to a predetermined group, MS and HS students were likely to defend their answer using form and habitat. Students who invoked morphology in their responses commonly cited the presence of a tail (MS—32.18%, HS—31.65%), gills (MS—14.94%, HS—12.23%), or a general statement about body structure (MS—10.34%, HS—12.23%). More than 80% of the students that used habitat as criteria stated that they grouped organisms by whether they lived in water. High school students were more likely to invoke an evolutionary relationship (these organisms have a similar common ancestor) as criteria for their grouping (MS—3.97%, HS—17.96%).

Our hierarchical cluster analysis showed that students who utilized process/function, taxonomy, and evolution formed a significant cluster, with taxonomy and evolution being more related (Fig. ). Students whose responses discuss taxonomy (e.g., birds are vertebrates like the predetermined group) were likely to also include evolution (e.g., birds share a more recent common ancestor with the predetermined group) in their criteria and, to a lesser extent, process/function. Responses of students who use form were likely to include habitat.

Lily pad/mushroom item

When students were prompted to choose whether a lily pad or mushroom belonged to an aforementioned group, MS and HS students were most likely to use form and taxonomy as rationale. Students who invoked form relied on the lily pad's green color (MS—56.25%, HS—62.65%) as their criteria for grouping (Table ). Many students differentiated between plants and fungi and subsequently used that as criteria, though more students mentioned that a lily pad was a plant (MS—63.64%, HS—56.76%) rather than saying that the mushroom was a fungus (MS—31.06%, HS—37.30%).

Our hierarchical cluster analysis showed that students who utilized form and taxonomy formed a cluster, suggesting that students who use form (e.g., the lily pad is green) as a rationale are significantly likely to also include taxonomic evidence (e.g., lily pads and the aforementioned group are plants; Fig. ). Students who used habitat as criteria were more likely to include evolution in their response and, to a lesser extent, process/function.

Three groups item

When students were asked to explain the rationale for why organisms were grouped in three predetermined groups, they were most likely to discuss process/function and taxonomy in their responses. Students who focused on process/function were likely to name functional groups (these organisms were consumers [MS—16.38%, HS—16.80%], producers [MS—25.00%, HS—22.00%], decomposers [MS—26.72%, HS—28.00%], etc.). Students who utilized taxonomy recognized different groupings (these were plants [MS—34.69%, HS—31.08%], fungi [MS—23.13%, HS—25.58%], animals [MS—18.37%, HS—19.66%], etc.). Interestingly, among both MS and HS student populations, there was a small number that utilized statements such as “Group ‘X’ are living” or “Group ‘X’ are organisms” (MS—9.52%, HS—8.20%), implying that not all the pictures were of living things or could be defined as an organism.

Our hierarchical cluster analysis showed that form, habitat, and evolution formed a significant cluster, with habitat and evolution being more closely related (Fig. ). Furthermore, students whose rationale included process/function were likely to include taxonomic criteria.

Discussion

How does this work relate to previous work on naming biodiversity?

Our results expand on students’ knowledge from the United States and corroborated some of the previous work on naming organisms, which included a majority of work abroad. Students listed vertebrates and invertebrates more often as compared to plants, and this distinction did not differ between MS and HS. Plant blindness has been documented in U.S. and European studies (Wandersee and Schussler , Patrick and Tunnicliffe ). The lack of plant knowledge is alarming because plants provide ecosystem services through provisions (e.g., food, fuel, medicine) and habitat regulation (e.g., water purification, preventing soil erosion; Costanza et al. ). Given that about a quarter of all plant species are endangered (IUCN ), and because high plant diversity is linked to proper ecosystem functioning, a changing plant species composition can significantly affect services (Isbell et al. ). As such, it is important to address plant blindness and educate students on the role, significance, and value of plants.

We were surprised and excited by the number of students who recognized the existence of microbial life in their backyard and that students named more microbial life than the teachers. It is important to note that these students had recently completed a unit on stream ecology that included looking at microscopic life that lives in streams. Microorganisms play an essential role in ecosystem processes, such as decomposition and nitrogen fixation, but are overlooked by many students when naming biodiversity in an area due to their size (Byrne ). Microbiology is inherently difficult due to the size of organisms and because the laboratory and computational techniques utilized can be conceptually overwhelming to students (Stewart et al. , Homburger et al. ). Additionally, many students view microorganisms negatively, noting that they are “germs” that cause diseases (Homburger et al. ) or simply ignore them because they are “hidden” (Sander et al. ). To engage students further with microbial diversity, some have emphasized medical microbiology and how we can use cell cultures to facilitate treatment for conditions in lieu of antibiotics (Jasti et al. ). Others suggest exposing students to the diversity and variation of structures that are possible for microbes through plush figures (Webb ).

When looking at specificity in naming, we found students more likely to use general terms (e.g., fish, bird, bug) when describing organisms rather than specific names (e.g., Blue Jay, trout, millipede). We expected this result because many students do not understand the value in naming organisms, and few curricula focus on local natural history (Bebbington , Soga and Gaston ). Previous literature has shown that beyond the ages of 8–9, the addition of new organism names to a child's vocabulary begins to wane (Balmford et al. ), a pattern that could stem from curriculum design that discourages informal and outdoor learning experiences (Braun et al. , Waite , Maynard et al. ). Naming organisms is considered a foundational aspect of learning about biodiversity; it is important to infuse this into the coursework and encourage students to learn organism names and organismal roles in the local ecosystem through experience (Randler , Soga and Gaston , Wyner and Doherty ).

In our study, teachers named significantly more organisms than students, especially plants. This supports the notion that teachers are more accurately portraying the organisms that live in a backyard. This could be due to the differences in their education level, experience, and training. However, the research is scarce, and some studies show no difference in teachers’ and students’ abilities to name organisms (Bebbington , Lindemann‐Matthies and Bose , Burgoon and Duran ). In addition to some of the reasons listed previously, we also hypothesize that the ability of teachers to name a more substantial number of organisms can be attributed to other factors, such as generational differences (today's students are less likely to spend time outdoors) and their locations of play during their childhood (if children are surrounded by trees, they will climb; if they are near creeks, they will swim; Piaget and Cook , Kinoshita ). Further, the teachers in our study were identified because they were affiliated with sites in the LTER. There is a selection bias for teachers who participated in professional development training at a field station, which may have positively influenced their naming abilities.

We note the novelty in how we analyzed naming and grouping biodiversity and recognize that previous studies were not able to do so. Diversity indices are commonly used by ecologists. By creating diversity indices, we were able to present data in a meaningful way that captured the variation of organisms that students and teachers named. By using hierarchical cluster analysis to describe the criteria students used in grouping organisms, we were able to describe and differentiate how student responded to the varying contexts. Note, these students had recently completed a unit on stream ecology, and thus, their participation in that unit might have impacted their perceptions about grouping organisms they may have encountered in their local streams (e.g., fish, crayfish).

The novelty of linking naming of diversity to conceptual understanding of ecology

We explored our original hypothesis that recognition of biodiversity is related to understanding more complex ecological patterns and relationships. There is very little published work in this area. One study showed that after an arthropod naming activity, MS students were better at understanding ecology terms in the context of biodiversity (Richardson and Hari ). This work contributes to the field in that we link familiarity with biodiversity to performance on an ecology learning progression. Our regression analyses showed that an individual's ability to name a diversity of organisms is correlated to EAP on the ecology learning progression assessment. This offers new insights and hypotheses on a student's conception of relationships in biodiversity. We note the exploratory nature of these models and that future work needs to be conducted to elucidate causal relationships between naming and conceptual understanding. However, we hope our work will motivate future research in terms of what, why, and how organismal diversity can be related to student understanding of ecosystem processes and structure.

Our models were made to explore potential relationships between familiarity with biodiversity and conceptual understanding of how biodiversity functions. We acknowledge, however, that the models were limited to the variables focused on what students named in their backyard/neighborhood. We believe that affective dimensions (e.g., feelings about wildlife, personal appreciation for biodiversity and nature) and sociocultural factors (e.g., time in class spent outside, norms established by the teacher) may also impact EAP. We suggest that future work includes these domains to help educators understand the factors that impact learning.

How does this work relate to previous research on describing relatedness among organisms?

Our results indicate that students used a variety of rationales to describe organismal relatedness. Generally, students used form, habitat, and function/process as rationale for choosing an organism (choosing organism A because its physical looks match those of the aforementioned group). Students are likely to focus more on physical features when they are describing organisms, especially in how they are related (Trowbridge and Mintzes , Braund , , Kattmann , Sander et al. , Cinici ). We recognize that the use of “traits” in this question set may have made students lean toward describing physical aspects of relatedness, but we want to recognize that despite this, a number of students still referred to taxonomy and evolution in their responses. Wyner and Doherty () supported the idea that taxonomy is less often invoked by students, and it is notable when they do that without prompting. However, we acknowledge and value the variety of rationales students use and adhere to the ideas of Ehrlich and Holm () when they state that relatedness can be conceptualized in many different ways (e.g., traits, taxonomy) and that all ways of knowing relatedness are valid.

Researchers have noted that understanding of relatedness in the context of phylogeny and evolution has been low in all student populations, and consequently, it is not surprising that few students utilize phylogeny and evolution as criteria for grouping (Trowbridge and Mintzes , , Yen et al. , Burgoon and Duran , Wyner and Doherty ). However, an understanding of phylogeny and evolution is needed to thoroughly understand biodiversity at multiple scales. As such, many educators are infusing “tree thinking” and evolution into biology curriculum and have developed modules that seek to enhance students’ understanding of these topics (Baum et al. ). Initial results from post‐secondary students indicate positive student outcomes, which can benefit future studies looking at how students think of relatedness among organisms (Smith and Cheruvelil , Smith et al. , Dees et al. ).

Recommendations for education based on these findings

The Next Generation Science Standards (NGSS; www.nextgenscience.org) were released in 2013 to improve science learning through three dimensions: science and engineering practices, crosscutting concepts, and disciplinary core ideas. Many of the ecology standards regarding biodiversity focused on recognizing relationships between plants and animals in an ecosystem (NGSS Lead States ). We suggest that at lower grade levels, teachers should focus on naming and becoming familiar with different types of organisms through experiences, as that will help facilitate more complex topics about relatedness and organismal interactions in the context of evolution and ecosystems ecology (Anderson and Doherty ).

Our recommendation regarding biodiversity stems from several factors. Previous work has shown that encouraging students to observe the natural world without direction and context can hinder a deeper understanding of ecology. In Eberbach's and Crowley's () work, they noted that recognition and naming may not be automatic to students learning about biodiversity unless the purpose and context is illuminated by teachers. Schauble's () work showed that gains were modest in open observations by children and adults when compared to a more structured observation experience. Positive learning experiences need to be structured and help students recognize why naming is an important skill and how it could potentially be used to ask more complex questions (Schauble et al. , Schauble ). During the implementation of our curriculum related to the learning progression work, we recognized that students needed to first become familiar with the organisms we were working with, before they could think about feeding relationships or trophic levels. We noticed that once students developed comfort and expertise in naming the organisms, they were then able to organize the organisms into groups that were related based on form and function and could then make connections to ecosystem structure and change.

Biodiversity is and will continue to be an important topic in biology education, especially with current issues in conservation and climate change. We see degradation of habitat, deforestation, severe weather, extirpations, and extinction events, which have gone unnoticed in the general population. To create well‐informed future citizens, we need to adequately train our students to recognize, understand, and appreciate biodiversity (Lindemann‐Matthies and Bose , Braun et al. , Dor‐Haim et al. , Arbuthnott and Devoe ). We recommend purposeful inclusion of classroom material that not only highlights biodiversity but also reiterates its importance, such as including units on classification using books and dichotomous keys. Additionally, we need to facilitate meaningful discussions on the environment, its importance, and potential ramifications of inaction; this requires a shift from advocacy to making the connection between biodiversity, ecosystem processes, and ecosystem services understandable to students and the public. An emphasis should be placed on studying plants, as many students have an inherent bias against learning more about their roles (Tunnicliffe , Wandersee and Schussler , Patrick and Tunnicliffe ). Science educators need to target students at younger ages and include more structured outdoor learning experiences to foster a positive relationship with the environment. From these interventions, we can create a generation that understands the importance of biodiversity and is more mindful about the consequences of our inaction.

Acknowledgments

We thank the teachers and students who participated in our project. We would also like to thank Elizabeth Pansing, Aaron Wagner, Allison Pierce, and Andrew McDevitt for their help with data analysis and coding. Further, we thank members of the research team including Alan Berkowitz, Charles (Andy) Anderson, Shawna McMahon, Stephanie Simmons, Mitch Burke, MaryAnn Murphy, and Brook Wilke. Lastly, we thank Dr. Diane Ebert‐May and two anonymous reviewers for their constructive feedback on earlier manuscript versions. This project was funded by the National Science Foundation Math Science Partnership Grant #0832173.