Folk Taxonomies and Biological Classification

Are we romanticizing traditional knowledge? A plea for more experimental studies in ethnobiology

In answer to the debate question "Is ethnobiology romanticizing traditional practices, posing an urgent need for more experimental studies evaluating local knowledge systems?" I suggest to follow-up on field study results adopting an inclusive research agenda, and challenge descriptive data, theories, and hypotheses by means of experiments. Traditional and local knowledge are generally associated with positive societal values by ethnobiologists and, increasingly also by stakeholders. They are seen as a way for improving local livelihoods, biocultural diversity conservation and for promoting sustainable development. Therefore, it is argued that such knowledge needs to be documented, protected, conserved in situ, and investigated by hypothesis testing. Here I argue that a critical mindset is needed when assessing any kind of knowledge, whether it is modern, local, indigenous, or traditional.

Cropping synonymy: varietal standardization in the United States, 1900-1970

This article examines crop varietal standardization in the United States. Numerous committees formed in the early twentieth century to address the problem of nomenclatural rules in the horticultural and agricultural industries. Making shared reference to a varietal name proved a difficult proposition for seed-borne crops because plant conformity tended to change in the hands of different breeders. Moreover, scientific and commercial opinions diverged on the value of deviations within crop varieties. I review the function of descriptive difference in the seed trade and in the framework of evolutionary theory before examining the institutional history of varietal standardization. Pimento peppers are used to represent how vegetables were treated differently than cereals. Lack of stability within a popular pimento variety caused problems for food packers in middle Georgia, which public breeders addressed by releasing new peppers. To conclude, the article questions the role of taxonomy in intellectual property, as breeding history and yield became defining attributes for making varietal distinctions.

UNA REFLEXIÓN SOBRE LA DIVERSIDAD CULTURAL Y EL CONOCIMIENTO DEL MEDIO AMBIENTE

Desde la tradición de la antropología lingüística se retoman las ideas de la diversidad cultural y el principio de la relatividad lingüística. Además de destacar a los autores centrales que aportaron para el estudio del lenguaje y su relación con la cultura y el pensamiento, se retoman los enfoques que surgieron a mediados del siglo pasado como la antropología cognitiva, la etnociencia y la etnografía del habla. Desde una reflexión teórica y metodológica se plantea la importancia de retomar la perspectiva complejo-transdiciplinaria que integre el análisis de la diversidad cultural, la diversidad lingüística y la biodiversidad. Tomar en cuenta la interacción del hombre con el medio ambiente que resulta fundamental para comprender de la memoria colectiva y los saberes comunitarios.

A study of the plant folk nomenclature of the Yi people in Xiaoliangshan, Yunnan Province, China, and the implications for protecting biodiversity

BACKGROUND

Folk plant nomenclature is a part of knowledge of indigenous people often used to distinguish plant species. This study aimed to document the folk botanical nomenclature of the Yi people in Xiaoliangshan, Yunnan Province, which has not been systematically investigated to date. The results of this study will assist in conserving biodiversity and the language of the Yi people and will promote the transmission of ethnobotanical knowledge.

METHODS

An ethnobotanical survey of plants used by the Yi people in Xiaoliangshan, Yunnan Province, was conducted from September 2019 to August 2021. Semi-structured interviews and key informant interviews were conducted to collect and document ethnobotanical information, which was then used to analyse the folk botanical nomenclature of the Yi people. In addition, the folk names of plants used by the Xiaoliangshan Yi community were compared with those of the Yi people living in the Daliangshan, where the environment is considerably different.

RESULTS

In this study, 266 informants were interviewed, and the names of 228 indigenous plants were extracted from 3088 use reports. The nomenclature used by the local Yi people is based on plant characteristics, plant habitat, plant use, and the local culture. By comparing the folk plant names of the Yi people in Xiaoliangshan with those of the Yi people in Daliangshan, we found that the plant names of the two places have some similarities and also with their own unique characters. The important folk plant names of the Yi people in Xiaoliangshan usually have a monosyllable non-binomial structure or have and "divine attributes" in their names.

CONCLUSIONS

The Yi people in Xiaoliangshan have a rich and diverse knowledge of plant naming determined by cultural, and environmental factors. The botanical nomenclature of the Yi people has distinct rules and characteristics, and the plant naming directly includes important plants that they believe to be used and protected, which is of great significance to the protection of biodiversity.

Conceptual issues in hominin taxonomy: Homo heidelbergensis and an ethnobiological reframing of species

Efforts to name and classify Middle Pleistocene Homo, often referred to as "Homo heidelbergensis" are hampered by confusing patterns of morphology but also by conflicting paleoanthropological ideologies that are embedded in approaches to hominin taxonomy, nomenclature, and the species concept. We deconstruct these issues to show how the field's search for a "real" species relies on strict adherence to pre-Darwinian essentialist naming rules in a post-typological world. We then examine Middle Pleistocene Homo through the framework of ethnobiology, which examines on how Indigenous societies perceive, classify, and name biological organisms. This research reminds us that across human societies, taxonomies function to (1) identify and classify organisms based on consensus pattern recognition and (2) construct a stable nomenclature for effective storage, retrieval and communication of information. Naming Middle Pleistocene Homo as a "real" species cannot be verified with the current data; and separating regional groups into distinct evolutionary lineages creates taxa that are not defined by readily perceptible or universally salient differences. Based on ethnobiological studies of this kind of patterning, referring to these hominins above the level of the species according to their generic category with modifiers (e.g., "European Middle Pleistocene Homo") is consistent with observed human capabilities for cognitive differentiation, is both necessary and sufficient given the current data, and will allow for the most clear communication across ideologies going forward.

Relationship of taxonomic error to frequency of observation

Biological nomenclature is the entry point to a wealth of information related to or associated with living entities. When applied accurately and consistently, communication between and among researchers and investigators is enhanced, leading to advancements in understanding and progress in research programs. Based on freshwater benthic macroinvertebrate taxonomic identifications, inter-laboratory comparisons of >900 samples taken from rivers, streams, and lakes across the U.S., including the Great Lakes, provided data on taxon-specific error rates. Using the error rates in combination with frequency of observation (FREQ; as a surrogate for rarity), six uncertainty/frequency classes (UFC) are proposed for approximately 1,000 taxa. The UFC, error rates, FREQ each are potentially useful for additional analyses related to interpreting biological assessment results and/or stressor response relationships, as weighting factors for various aspects of ecological condition or biodiversity analyses and helping set direction for taxonomic research and refining identification tools.

Microscopic Authentication of Commercial Herbal Products in the Globalized Market: Potential and Limitations

Herbal products are marketed and used around the globe for their claimed or expected health benefits, but their increasing demand has resulted in a proportionally increase of their accidental contamination or intentional adulteration, as already confirmed with DNA-based methods. Microscopy is a traditional pharmacopoeial method used for plant identification and we systematically searched for peer-reviewed publications to document its potential and limitations to authenticate herbal medicines and food supplements commercially available on the global market. The overall authenticity of 508 microscopically authenticated herbal products, sold in 13 countries, was 59%, while the rest of 41% were found to be adulterated. This problem was extending over all continents. At the national level, there were conspicuous differences, even between neighboring countries. These microscopically authenticated commercial herbal products confirm that different magnifying instruments can be used to authenticate crude or processed herbal products traded in the global marketplace. The reviewed publications report the successful use of different magnifying instruments, single or in combinations with a second one, with or without a chemical or DNA-based technique. Microscopy is therefore a rapid and cost-efficient method, and can cope with mixtures and impurities. However, it has limited applicability for highly processed samples. Microscopic authentication of commercial herbal products will therefore contribute to raise public awareness for the extent of adulteration and the need to safeguard consumer safety against the challenges of globalization.

From Folk Taxonomy to Species Confirmation of Acorus (Acoraceae): Evidences Based on Phylogenetic and Metabolomic Analyses

Plants in Acorus have been used as herbal medicine by various linguistic groups for thousands of years. Arguments of taxonomy of Acorus among scientists resulted in confusions and misuses of Acorus plants. The present study used different methods to investigate the classification of the genus, based on folk taxonomy. The relationships among Acorus species were revealed through phylogenetic analyses by constructing the Maximum Likelihood and Bayesian phylogenetic analyses based on sequences of two chloroplast regions (trnL-trnF and rbcL). All samples named with two so-called synonyms, Acorus macrospadiceus (Yamam.) F. N. Wei and Y. K. Li and Acorus tatarinowii Schott collected from different habitats, were clustered into separate groups, which revealed that they represented two independent species. Multivariate statistical analysis of metabolites from different Acorus populations were carried out based on UPLC-QTOF-MS data. Three independent analysis, principal component analysis, heat-map analysis, and hierarchical cluster analysis, showed that A. macrospadiceus and A. tatarinowii are different from two recognized species in the genus, A. calamus L. and A. gramineus Aiton. The results of phylogenetics and chemotaxonomy, together with morphological and ecological evidences, were consistent with traditional knowledge of local people related to Acorus taxa, which proved the significance of parataxonomy. Multiple evidences including morphological, ecological, folk taxonomic, phylogenetic, and chemical taxonomic results suggested that there are four species in the genus Acorus.

Plants utilized as medicines by residents of Quilombo da Fazenda, Núcleo Picinguaba, Ubatuba, São Paulo, Brazil: A participatory survey

ETHNOPHARMACOLOGICAL RELEVANCE

Participatory research can help to broaden the understanding of medical systems and beliefs of traditional communities. An ethnopharmacological survey in collaboration with local people focused on plants used in quilombos located in Southeast Region in Brazil identified cultural factors that influence plant and recipe choice.

AIM OF THE STUDY

To investigate the factors related to the therapeutic efficiency of medicinal plants from the perspective of Quilombo da Fazenda residents.

MATERIALS AND METHODS

University researchers collaborated with community residents for both aims and methods of the study. The local partners were trained in the gathering of ethnopharmacological data and then selected and interviewed the residents considered experts on the use of medicinal plants. Data on the use of each species were supported by voucher specimens collected by the local partners and university researchers. Participant observations and field diaries by the university researchers supplemented the data.

RESULTS

Eight interviewees mentioned 92 medicinal species with 60 therapeutic uses, applied in 208 recipes or remedies. Asteraceae (13 species), Lamiaceae (5) and Urticaceae (5) contributed most medicinal plant species. Of the 12 etic categories of use, the circulatory system category had the highest number of plants mentioned. Decoction was the most commonly used preparation method (66.8%), and most remedies were administered orally (76.4%). Eighty-six recipes included more than one plant species and/or the addition of other components, such as sugar, salt or animal products. Several cultural factors influence medicinal plant use. Popular beliefs on the quality of blood or the humoral properties of plants and illnesses, characteristics of the plants and other factors determine which plant is used and why.

CONCLUSIONS

The participatory method identified a large number of factors that influence medicinal plant use: the patient's blood type; the condition of the plant and the disease (hot-cold system); the route of administration and dosage; the preventive uses of the plants; and the influence of other factors, such as the sun, the moon and dew. The participatory approach is useful for gaining insight on the decision processes of medicinal plant use in traditional societies, and also for those communities wanting to document their knowledge with or without the participation of the academy.

Product authenticity versus globalisation-The Tulsi case

Using the Indian medicinal plant Tulsi (Holy Basil) as a case study, we have tested to what extent the discrepancy between vernacular and scientific nomenclature can be resolved, whether the presumed chemical diversity underlying the medicinal use of Tulsi has a genetic component, and whether it is possible to detect this genetic component using genetic barcoding markers. Based on four plastidic markers, we can define several haplotypes within Ocimum that are consistent across these markers. Haplotype II is congruent with O. tenuiflorum, while haplotype I extends over several members of the genus and cannot be resolved into genetically separate subclades. The vernacular subdivision of Tulsi into three types (Rama, Krishna, Vana) can only be partially linked with genetic differences-whereby Rama and Krishna Tulsi can be assigned to O. tenuiflorum, while Vana Tulsi belongs to haplotype I. This genetic difference is mirrored by differences in the profiles of secondary compounds. While developmental state and light quality modulate the amplitude to which the chemical profile is expressed, the profile itself seems to be linked with genetic differences. We finally develop an authentication assay that makes use of a characteristic single nucleotide polymorphism in one of the barcoding markers, establishing a differential restriction pattern that can be used to discriminate Vana Tulsi.

Plantas medicinales usadas en algunas veredas de municipios del altiplano del Oriente antioqueño, Colombia

Con el objetivo de conocer y determinar la importancia relativa de las plantas usadas como medicinales, se realizó un estudio etnobotánico en las comunidades campesinas de algunas veredas de seis municipios del Altiplano del Oriente antioqueño: El Carmen de Viboral, El Retiro, Guarne, La Ceja, Marinilla y Rionegro, región correspondiente a la zona de vida denominada bosque húmedo montano bajo (bh-MB). Se recopiló información sobre plantas medicinales silvestres o espontáneas y plantas medicinales cultivadas, introducidas casi desde la época de la conquista o la colonia y que son de uso muy arraigado entre las comunidades de la zona de estudio. Con la información suministrada por 17 informantes de las diferentes veredas, se registraron 254 especies de plantas usadas como medicinales en el altiplano del Oriente antioqueño, agrupadas en 193 géneros correspondientes a 79 familias. La mitad de las especies mencionadas en este estudio (127) son silvestres o no cultivadas y se encuentran principalmente en áreas de vegetación secundaria como bordes de camino, potreros, matorrales, rastrojos y bordes de corrientes acuáticas, entre otros hábitats. Las otras 127 especies usadas como medicinales en la región del estudio, son cultivadas como alimenticias, ornamentales, esotéricas, maderables, medicinales, generalmente en huertas familiares y huertas especializadas para cultivos de plantas medicinales para la venta. El trabajo es un aporte al conocimiento de la flora medicinal de Colombia y al rescate del conocimiento tradicional sobre el uso de las plantas medicinales.

Schooling, Local Knowledge and Working Memory: A Study among Three Contemporary Hunter-Gatherer Societies

Researchers have analysed whether school and local knowledge complement or substitute each other, but have paid less attention to whether those two learning models use different cognitive strategies. In this study, we use data collected among three contemporary hunter-gatherer societies with relatively low levels of exposure to schooling yet with high levels of local ecological knowledge to test the association between i) schooling and ii) local ecological knowledge and verbal working memory. Participants include 94 people (24 Baka, 25 Punan, and 45 Tsimane’) from whom we collected information on 1) schooling and school related skills (i.e., literacy and numeracy), 2) local knowledge and skills related to hunting and medicinal plants, and 3) working memory. To assess working memory, we applied a multi-trial free recall using words relevant to each cultural setting. People with and without schooling have similar levels of accurate and inaccurate recall, although they differ in their strategies to organize recall: people with schooling have higher results for serial clustering, suggesting better learning with repetition, whereas people without schooling have higher results for semantic clustering, suggesting they organize recall around semantically meaningful categories. Individual levels of local ecological knowledge are not related to accurate recall or organization recall, arguably due to overall high levels of local ecological knowledge. While schooling seems to favour some organization strategies this might come at the expense of some other organization strategies.

Continuity and change in medicinal plant use: the example of monasteries on Cyprus and historical iatrosophia texts

ETHNOPHARMACOLOGICAL RELEVANCE

How medicinal plant knowledge changes over time is a question of central importance in modern ethnopharmacological research. However, only few studies are available which undertook a comprehensive exploration of the evolution of plant use in human cultures.

AIMS

In order to understand this dynamic process, we conduct a systematic diachronic investigation to explore continuity and change in two knowledge systems which are closely related but separated in time-historical iatrosophia texts and today's Greek Orthodox monasteries on Cyprus.

MATERIALS AND METHODS

An ethnobotanical study was conducted in 21 of the island's monasteries involving various types of interview as well as a written questionnaire survey. Data about medicinal plant use collected in the monasteries was analysed and quantitatively compared to historical iatrosophia texts using data from our pre-existing dataset.

RESULTS

We found a core group of plant taxa for which a high consensus exists among the monasteries regarding their medicinal usefulness. Various means and routes of knowledge transmission appear to be involved in the development of this knowledge. The systematic comparison between the monasteries and the iatrosophia shows similarities and differences on various levels. While the plants used by the nuns and monks have by the majority a relationship to the iatrosophia and show a remarkable historical consistency in terms of their use for defined groups of ailments, the importance of many of these plants and the use of herbal medicines in general have changed.

CONCLUSIONS

This is one of the first studies from the Mediterranean region which is based on a systematic ethnopharmacological analysis involving comprehensive datasets of historical and modern ethnographic data. The example illustrates continuity and change in 'traditional' knowledge as well as the adoption of new knowledge and provides the opportunity to look beyond the dichotomy between traditional and modern concepts of plant usage. Overall, the study suggests that a systematic diachronic approach can facilitate a better understanding of the complex and dynamic processes involved in the development of medicinal plant knowledge.

Cultural change and loss of ethnoecological knowledge among the Isthmus Zapotecs of Mexico

BACKGROUND

Global changes that affect local societies may cause the loss of ecological knowledge. The process of cultural change in Zapotec communities of the Oaxacan Isthmus intensified during the first years of the 20th century due to industrial and agro-industrial modernization projects and an increase in the level of formal schooling. Based on the case of the Oaxacan Isthmus, this study assesses the relationship between cultural change and the loss of traditional ecological knowledge (TEK).

METHODS

Three hundred male heads of family were interviewed from three municipalities in the Isthmus of Tehuantepec, Oaxaca, Mexico selected to span a wide range of cultural change. Each participant was shown herbarium specimens and photographs of a sample of 30 species drawn from a pool of 94 representing local plant diversity. Visual recognition of each species, knowledge of plant form, generic name, specific name, and local uses were scored. The sum of the five scores provided an index of global knowledge which we used as a proxy for TEK. Analysis of variance revealed differences between groups of economic activities. We collected socio-demographic data from the interviewees such as age, level of schooling, and competency in the local language. With these data we ran a principal component analysis and took the first axis as an index of cultural change, and correlated it with the scores obtained each respondent.

RESULTS

We found statistically significant differences between groups of people with different economic activities, as well as a highly significant negative relationship between the Index of cultural change and ecological knowledge at all levels, with regression coefficients between 81.2% and 88.3%, indicating that cultural change is affecting traditional botanical knowledge.

CONCLUSIONS

Our results shown that cultural change, as indicated by occupational activity, level of formal schooling, and competence in the indigenous language, is negatively associated with the loss of Zapotec ethnobotanical knowledge. Heads of family engaged in secondary economic activities and services were less culturally competent, especially regarding the knowledge of generic and specific names as well as plant uses.

Wild plant folk nomenclature of the Mongol herdsmen in the Arhorchin National Nature Reserve, Inner Mongolia, PR China

BACKGROUND

Folk names of plants are the root of traditional plant biodiversity knowledge. In pace with social change and economic development, Mongolian knowledge concerning plant diversity is gradually vanishing. Collection and analysis of Mongolian folk names of plants is extremely important. During 2008 to 2012, the authors have been to the Arhorchin National Nature Reserve area 5 times. Fieldwork was done in 13 villages, with 56 local Mongol herdsmen being interviewed. This report documents plant folk names, analyzes the relationship between folk names and scientific names, looks at the structure and special characteristics of folk names, plant use information, and comparative analysis were also improved.

METHODS

Ethnobotanical interviewing methods of free-listing and open-ended questionnaires were used. Ethnobotanical interview and voucher specimen collection were carried out in two ways as local plant specimens were collected beforehand and then used in interviews, and local Mongol herdsmen were invited to the field and interviewed while collecting voucher specimens. Mongolian oral language was used as the working language and findings were originally recorded in Mongolian written language. Scientific names of plants are defined through collection and identification of voucher specimens by the methods of plant taxonomy.

RESULTS

A total of 146 folk names of local plants are recorded. Plant folk names corresponded with 111 species, 1 subspecies, 7 varieties, 1 form, which belong to 42 families and 88 genera. The correspondence between plant folk names and scientific names may be classified as one to one correspondence, two or three to one correspondence, and one to multitude correspondence. The structure of folk names were classified as primary names, secondary names and borrowed names. There were 12 folk names that contain animal names and they have correspondence with 15 species. There are nine folk names that contain usage information and they have correspondence with 10 species in which five species and one variety of plant are still used by the local people. The results of comparative analysis on the Mongol herdsmen in the Arhorchin National Nature Reserve and the Mongolians in the Ejina desert area shows that there are some similarities, as well as many differences whether in language or in the structure.

CONCLUSION

In the corresponding rate between plant folk names and scientific names yielded a computational correspondence of 82.19%, which can be considered as a high level of consistency between scientific knowledge and traditional knowledge in botanical nomenclature. Primary names have most cultural significance in the plant folk names. Special characteristic of plant folk names were focused on the physical characteristics of animals which were closely related to their traditional animal husbandry and environment. Plant folk names are not only a code to distinguish between different plant species, but also a kind of culture rich in a deep knowledge concerning nature. The results of comparative analysis shows that Mongolian culture in terms of plant nomenclature have characteristics of diversity between the different regions and different tribes.

A taxonomist's view on genomic authentication

A brief history of taxonomy, for the most part plant oriented, is provided, which demonstrates the use of morphology early on, through the stages when different technologies became available at different times until the present use of genomic tools. Genomic authentication facilitates with greater precision than ever before the identification of an organism or part thereof. In this chapter I made an attempt to stress that, in general, but more so for genomic authentication, the use of the variation inherent in taxa down to the lowest level of the hierarchy of classification needs to be used to achieve a high degree of correct authentication.

Inter-observer agreement on subjects' race and race-informative characteristics

Health and socioeconomic disparities tend to be experienced along racial and ethnic lines, but investigators are not sure how individuals are assigned to groups, or how consistent this process is. To address these issues, 1,919 orthodontic patient records were examined by at least two observers who estimated each individual's race and the characteristics that influenced each estimate. Agreement regarding race is high for African and European Americans, but not as high for Asian, Hispanic, and Native Americans. The indicator observers most often agreed upon as important in estimating group membership is name, especially for Asian and Hispanic Americans. The observers, who were almost all European American, most often agreed that skin color is an important indicator of race only when they also agreed the subject was European American. This suggests that in a diverse community, light skin color is associated with a particular group, while a range of darker shades can be associated with members of any other group. This research supports comparable studies showing that race estimations in medical records are likely reliable for African and European Americans, but are less so for other groups. Further, these results show that skin color is not consistently the primary indicator of an individual's race, but that other characteristics such as facial features add significant information.

The origins of taxonomy

There are approximately 10 million kinds of olganisms in the world, of which we have described some 15 percent. The rapid growth of the human population will cause most of the remainder to disappear from the earth before they are seen by a taxonomist. These facts suggest a more rigorous application of priorities in systematic biology as well as a careful review of the principles upon which our taxonomic system is based. Folk taxonomies all over the world are shallow hierarchically and comprise a strictly limited number of generic taxa ranging from about 250 to 800 forms applied to plants and a similar number applied to animals. These numbers are consistent, regardless of the richness of the environment in which the particular people live. Very few specific and varietal taxa are recognized in folk taxonomic systems. Until the invention of movable type in the mid-l5th century, written taxonomies were simply records of the folk taxonomies of particular regions. Subsequently, with the possibility for the wide distribution of books, it began to seem worth while to attempt to describe and name all species of plants and animals in the world. By the year 1700, 698 genera of plants were recognized; and by the year 1778, some 1350 genera, including tens of thousands of species. In 1789 de Jussieu interpolated the family as a higher level taxonomic category in an attempt to reduce the number of important units in the system to a memorable number. The family is still the focal point in systems of angiosperm classification at present, several hundred families being recognized. Problems with the taxonomic system stem largely from the fact that it is not designed as an information retrieval device. In folk taxonomies, names are given to organisms and these are used to communicate about the organisms with others who already know the culturally significant properties of the organisms being discussed. In dealing with the vast numbers of organisms that exist, we tend to overemphasize the process of classification and the decisions it involves at the expense of the information about the organisms that we are supposedly accumulating. Frequent changes in names exacerbate the difficulties of the system and render it still less useful for information retrieval. With modern electronic data processing equipment, it has become possible to record information about organisms, to retain this information in a data bank, and to utilize it for various purposes, including the construction of various taxonomic systems. The invention of high-speed electronic data processing equipment is seen as analogous to but more important than the invention of movable type in the history of systematic biology. By using such equipment to its full potentialities, we should be able to achieve a qualitative improvement in our perception of the living world.

Taxa, life, and thinking

He who understands baboon

would do more toward metaphysics than Locke.

Charles Darwin, August 16, 1838

I shall answer the commentaries by proceeding from strictly philosophical matters to biology, to psychology, and then to politics and the social sciences.

Categories, life, and thinking

Classifying is a fundamental operation in the acquisition of knowledge. Taxonomic theory can help students of cognition, evolutionary psychology, ethology, anatomy, and sociobiology to avoid serious mistakes, both practical and theoretical. More positively, it helps in generating hypotheses useful to a wide range of disciplines. Composite wholes, such as species and societies, are “individuals” in the logical sense, and should not be treated as if they were classes. A group of analogous features is a natural kind, but a group of homologous features is not. Imposing hypotheses justified only on the basis of nominalist, realist, phenomenalist, or conceptualist metaphysics upon the neurophysiology of organisms or upon the causes of behavior exemplifies the “psychologist's fallacy” of William James. Levels should be distinguished from their members and from classes of levels, and the ontological status of entities ranked at levels should be made clear. It is important not to confuse such categories as substance and process with one another. Several genetical terms, such as “gene” and chromosome,” are even more equivocal than has been realized. Discussions about units of selection, behavior, and thinking suffer from the ambiguity of a “unit of” an entity. An important source of misunderstanding about natural selection is the habit of treating it as an “agent”: in an important sense, natural selection does not “act” at all.

Language is not just for talking: redundant labels facilitate learning of novel categories

In addition to having communicative functions, verbal labels may play a role in shaping concepts. Two experiments assessed whether the presence of labels affected category formation. Subjects learned to categorize "aliens" as those to be approached or those to be avoided. After accuracy feedback on each response was provided, a nonsense label was either presented or not. Providing nonsense category labels facilitated category learning even though the labels were redundant and all subjects had equivalent experience with supervised categorization of the stimuli. A follow-up study investigated differences between learning verbal and nonverbal associations and showed that learning a nonverbal association did not facilitate categorization. The findings show that labels make category distinctions more concrete and bear directly on the language-and-thought debate.