Philosophy of Biology

The Cultural Evolution Society was established in 2015 to “catalyze a theoretical synthesis” in the scientific study of human culture. As a field of research, cultural evolution took shape in the 1970s and 1980s around the aim of incorporating culture into biology’s modern evolutionary synthesis. Cultural evolution grew around the turn of the twenty-first century at the interface of population genetics and cognitive psychology. This article locates the origins of research on cultural evolution in projects of postwar scientific antiracism and (...) U.S.-based debates about race and intelligence in the 1960s. Charting the development of prominent approaches to studying cultural evolution, I show how population geneticists and cognitive psychologists worked to redefine culture in statistical, populational, and geographic terms to politically neutralize the study of human difference. I situate the forms of genetic and cognitive culturalism that emerged as a result in a longer history of twentieth-century scientific antiracism. (shrink)

Big History expands the scope of historiography to study all the past, from the Big Bang to the present. Big History is decidedly non-anthropocentric, recognising that humans appeared only very recently from a much deeper past. The Bloomsbury Handbook of Big History brings together an international cast of leading and emerging scholars from a range of disciplines to provide the first comprehensive and balanced exploration of this new and increasingly significant field. -/- The handbook considers the ways in which Big (...) History broadens the scope of evidence historians use. It reveals how Big History allows for the use of information signals from the past, such as material remains, languages, ancient DNA, and fossils, using recently discovered techniques such as carbon-dating, the extraction of ancient DNA, and the analysis of background radiation from the origin of the universe. -/- Understanding Big History requires an examination of the ontology and epistemology of the past and its scientific inference and representation; chapters on the ontology of the past, historical information, historiographic experiments and predictions, the origin and the end of history, historical counterfactuals, contingency, necessity, and determination and under-determination of the past are included to facilitate this understanding. The handbook also provides a sustained analysis of the theoretical assumptions associated with synthetic historical science: the syntheses of genetics, linguistics, and archaeology to infer human prehistory, quantum physics and cosmology to infer the origin of the universe, and environmental science and biology to infer the history of life; as well as the distinct historical sciences and their methods: cosmology, evolutionary biology, geology, archaeology, historical linguistics, and human historiography. -/- This ground-breaking volume is vital reading for all historians, philosophers and historical scientists interested in becoming more scientifically self-conscious when adopting philosophical, theoretical, and methodological approaches to the past. (shrink)

The dominant paradigm in biomedicine focuses on genetically‐specified components of cells and their biochemical dynamics, emphasizing bottom‐up emergence of complexity. Here, I explore the biomedical implications of a complementary emerging field: diverse intelligence. Using tools from behavioral science and multiscale neuroscience, we can study development, regenerative repair, and cancer suppression as behaviors of a collective intelligence of cells navigating the spaces of possible morphologies and transcriptional and physiological states. A focus on the competencies of living material—from molecular to organismal scales—reveals (...) a new landscape for interventions. Such top‐down approaches take advantage of the memories and homeodynamic goal‐seeking behavior of cells and tissues, offering the same massive advantages in biomedicine and bioengineering that reprogrammable hardware has provided information technologies. The bioelectric networks that bind individual cells toward large‐scale anatomical goals are an especially tractable interface to organ‐level plasticity, and tools to modulate them already exist. This suggests a research program to understand and tame the software of life for therapeutic gain by understanding the many examples of basal cognition that operate throughout living bodies. (shrink)

Living systems are complex systems made of components that tend to degrade, but nonetheless they maintain themselves far from equilibrium. This requires living systems to extract energy and materials from the environment and use them to build and repair their parts. They do so by regulating their activities on the basis of their internal and external conditions in ways that allow them to keep living. The philosophical and theoretical approach discussed in this book aims to explain these features of biological (...) systems by appealing to their organization. One of its distinctive features is that it addresses classical and more recent issues in philosophy of biology, from origins and definitions of life to biological teleology and functions, from an original perspective mainly focused on the living system, its physiology and behavior, rather than evolution. The book discusses and revises the conceptual foundations of this approach and presents an updated version of it. (shrink)

Alles entwickelt sich: der Kosmos mit seinen Strukturen, das Leben auf der Erde und die atemberaubend kreative Intelligenz (auch die künstliche) sowie unser Verständnis von alledem. Dieses Buch ist der menschlichen und nichtmenschlichen Natur auf der Spur. Es handelt von Grundsatzfragen der Erkenntnis- und Wissenschaftstheorie, von Präzisierungen der modernen Naturphilosophie und von vielen weiteren Facetten humanistischer Kultur. Leitidee ist die Einheit des Wissens im Lichte der Evolution. -/- Gerhard Vollmer zählt mit seinen Publikationen (die meisten im Hirzel-Verlag!) zur Erkenntnis- und (...) Wissenschaftstheorie, Naturphilosophie und Metaphysik und über ein evolutionäres, naturalistisches Weltbild zu den bedeutendsten Philosophen der letzten 50 Jahre im deutschsprachigen Raum. Viel beigetragen hat er auch zum interdisziplinären Diskurs und zur Wissenschaftskommunikation – von seinem akademischen Wirken ganz zu schweigen. -/- Autoren und Themen: -/- "Evolutionäre Erkenntnistheorie bei Schopenhauer - eine Spurensuche" - Prof. Dr. Dieter Birnbacher ist emeritierter Professor für Philosophie an der Universität Düsseldorf. Vizepräsident der Deutschen Gesellschaft für Humanes Sterben sowie der Schopenhauer-Gesellschaft, Mitglied der Leopoldina. -/- "Das Realismusproblem in der Evolutionären Erkenntinstheorie" - Florian Chefai ist Direktoriumsmitglied und wissenschaftlicher Koordinator des Hans-Albert-Instituts. Studium der Philosophie und Soziologie in Trier. Seit 2020 Referent für Presse- und Öffentlichkeitsarbeit bei der Giordano-Bruno-Stiftung. -/- "Evolution und Politik - oder: Wie man Türen öffnet" - Dr. Gerhard Engel ist Philosoph und Evolutionärer Humanist. 1988 Promotion im Fach Wissenschaftslehre bei Hans Albert, danach Lehrtätigkeit in Braunschweig, Mainz und Nordhausen. 2009 bis 2017 war er Präsident der Humanistischen Akademie Bayern. -/- "Auf der Suche nach der Objektivität" - Helmut Fink ist Theoretischer Physiker und Referent für Wissenschaft und Philosophie bei Kortizes – Institut für populärwissenschaftlichen Diskurs in Nürnberg. Seit 2013 Vorstandsmitglied der Heisenberg-Gesellschaft, seit 2017 Vorsitzender der Ludwig-Feuerbach-Gesellschaft. -/- "Materie und Emergenz - ein wirkungsvolles Duo" - Prof. Dr. Ernst Peter Fischer ist Wissenschaftshistoriker und -publizist. 1977 Promotion in Biologie bei Max Delbrück, 1987 Habilitation in Wissenschaftsgeschichte, danach Lehrtätigkeit in Konstanz und Heidelberg. -/- "Die Evolution als Ideengeber für eine Systematische Kreativität" - PD Dr. Dr. Ulrich Frey ist Philosoph und Ökologe. 2006 Promotion in Philosophie bei Gerhard Vollmer, 2016 Promotion zum Dr. rer. nat. bei Eckart Voland, 2017 Habilitation in Ökologie in Gießen. Forscher am Deutschen Zentrum für Luft- und Raumfahrt in Stuttgart. -/- "Die Dynamik der Ignoranz in den Wissenschaften" - Prof. Dr. Paul Hoyningen-Huene ist promovierter Theoretischer Physiker, pensionierter Professor für Theoretische Philosophie an der Leibniz Universität Hannover und Lehrbeauftragter für Wirtschaftsphilosophie an der Universität Zürich. Mitglied der Leopoldina. "KI: Neues Denkzeug oder Evolutionssprung?" - Prof. Dr. Hartmut Kliemt ist emeritierter Professor für Philosophie und Ökonomik an der Frankfurt School of Finance and Management und Gastprofessor für Verhaltens- und Institutionenökonomik an der Universität Gießen. -/- "Warum manche Warum-Fragen immer wieder neu beantwortet werden" - Prof. Dr. Meinard Kuhlmann ist Wissenschaftsphilosoph im Philosophischen Seminar und im Studium Generale der Universität Mainz. 2012 bis 2021 Sprecher der Arbeitsgemeinschaft Philosophie der Physik der Deutschen Physikalischen Gesellschaft. -/- "Sind die sogenannten 'Critical Studies' Kandidaten für Pseudowissenschaften?" - Dr. Martin Mahner ist Biologe und Wissenschaftstheoretiker. Von 1999 bis 2024 leitete er das Zentrum für Wissenschaft und kritisches Denken der Gesellschaft zur wissenschaftlichen Untersuchung von Parawissenschaften (GWUP) in Roßdorf bei Darmstadt. -/- "Das Realismusproblem in der Evolutionären Erkenntnistheorie" - Dr. Jonas Pöld ist Direktoriumsmitglied des Hans-Albert-Instituts. Studium der Philosophie, Wissenschaftstheorie und Literaturwissenschaft in Berlin und Münster. 2024 Promotion in Philosophie in Münster. -/- "Im Lichte der Evolution: Kultur" - Dr. Dr. Hannes Rusch ist Verhaltensökonom. Promotionen 2014 in Biologie in Gießen und 2020 in Ökonomik in München. Seit 2023 Forschungsgruppenleiter am Max-Planck-Institut zur Erforschung von Kriminalität, Sicherheit und Recht in Freiburg. -/- "Nietzsche und die Wissenschaft des 19. Jahrhunderts" - Prof. Dr. Claus-Artur Scheier ist emeritierter Professor für Philosophie an der Technischen Universität Braunschweig. Arbeitsgebiete vor allem Metaphysik, Ästhetik und Deutscher Idealismus. Mitglied der Braunschweigischen Wissenschaftlichen Gesellschaft. -/- "Auf Epikurus Schultern - eine kurze Geschichte des Naturalismus" - Dr. Dr. h.c. Michael Schmidt-Salomon ist Philosoph, Schriftsteller und Vorstandssprecher der Giordano-Bruno-Stiftung für Humanismus und Aufklärung. 1997 Promotion zum Dr. phil. in Trier, 2019 Dr. h.c. der TU Liberec (Reichenberg). -/- "»Spiegel«-Leser wissen mehr – Reflexionen über Evolutionäre Erkenntnistheorie" - Prof. Dr. Volker Sommer ist Primatologe und Anthropologe. Seit 1996 Professor für Evolutionäre Anthropologie am University College London. Er erforscht Ökologie und Verhalten wild lebender Primaten in Afrika und Asien. -/- "Warum manche Warum-Fragen immer wieder neu beantwortet werden" - Prof. Dr. Manfred Stöckler ist Theoretischer Physiker und Philosoph. 1981 Promotion zum Dr. phil. in Gießen. 1991 bis 2017 Professor für Theoretische Philosophie mit dem Schwerpunkt Naturphilosophie und Philosophie der Naturwissenschaften an der Universität Bremen. -/- "Gerhard Vollmer als Philosophiedidaktiker – vom Lernen auf Vorrat, einer immer noch nötigen Fragekultur und dem Wert guter Beispiele" - Dr. Thomas Sukopp ist Akademischer Rat am Philosophischen Seminar, Arbeitsgemeinschaft Philosophiedidaktik, der Universität Siegen. 2006 Promotion in Philosophie bei Gerhard Vollmer, danach Lehrtätigkeit unter anderem in Braunschweig, Bamberg und Augsburg, seit 2012 in Siegen. -/- "Die Evolution des Kosmos - Zufall und Notwendigkeit im Multiversum" - Rüdiger Vaas ist Philosoph, Publizist, Astronomie- und Physikredakteur des Monatsmagazins bild der wissenschaft. Mitherausgeber mehrerer Buchreihen. Arbeitsgebiete vorwiegend Naturphilosophie und Wissenschaftstheorie der Grundlagenphysik und Kosmologie. -/- "Im Lichte der Evolution: Kultur" - Prof. Dr. Eckart Voland ist emeritierter Professor für Philosophie der Biowissenschaften an der Universität Gießen. Forschungen und Publikationen über Soziobiologie, zur historischen Demographie und evolutionären Anthropologie. -/- "Nikolaus Kopernikus - der missverstandene Astronom" - Prof. Dr. Franz Josef Wetz ist Philosoph und lehrte 1994 bis 2024 an der Pädagogischen Hochschule Schwäbisch Gmünd. 1981 bis 1993 wissenschaftlicher Mitarbeiter am Zentrum für Philosophie und Grundlagen der Wissenschaft der Universität Gießen. (shrink)

This essay looks at electromagnet rays and their role in visual perception. It is an update of the earlier version, of similar title.

The rapid rise of generative AI, including LLMs, has prompted a great deal of concern, both within and beyond academia. One of these concerns is that generative models embed, reproduce, and therein potentially perpetuate all manner of bias. The present study offers an alternative perspective: exploring the potential of LLMs to detect bias in human generated text. Our target is genetic essentialism in obesity discourse in Australian print media. We develop and deploy an LLM-based classification model to evaluate a large (...) sample of relevant articles (n=26,163). We show that our model detects genetic essentialist biases as reliably as human experts; and find that, while genes figure less prominently in popular discussions of obesity than previous work might suggest, when genetic information is invoked, it is often presented in a biased way. Implications for future work are discussed. (shrink)

This article defends a selective eliminativist position with respect to the concept of “biological lineage” as used in certain areas of contemporary evolutionary biology. We argue that its primary epistemic roles in these contexts—explaining social evolution and cumulative selection—clash with empirical evidence, and that enforcing the concept of “lineage” even obstructs fruitful research avenues in several biological research fields, including phylogenetic research. Drawing on this, we suggest that, in many instances, it would be best to get rid of the concept (...) of “lineage” and think in terms that are more closely aligned with the empirical complexity of the biological world. Specifically, this entails that, instead of looking for the lineage that may have given rise to the entities possessing certain biological characteristics, biologists should generally look for any potential process allowing such possession, with the formation of a lineage just one possibility among many. (shrink)

Microbiome research is changing how ecosystems, including animal bodies, are understood. In the case of humans, microbiome knowledge is transforming medical approaches and applications. However, the field is still young, and many conceptual and explanatory issues need resolving. These include how microbiome causality is understood, and how to conceptualize the role microbiomes have in the health status of their hosts and other ecosystems. A key concept that crops up in the medical microbiome literature is “balance.” A balanced microbiome is thought (...) to produce health and an imbalanced one disease. Based on a quantitative and qualitative analysis of how balance is used in the microbiome literature, this “think again” essay critically analyses each of the several subconceptions of balance. As well as identifying problems with these uses, the essay suggests some starting points for filling this conceptual gap in microbiome research. (shrink)

This paper challenges “biodiversity skepticism:” an inferential move that acknowledges the proliferation, heterogeneity, and lack of covariance of biodiversity measurements, and concludes that we should doubt the scientific validity of the biodiversity concept. As a way out of skepticism, philosophers have advocated for eliminating “biodiversity” from scientific inquiry, revising it, or deflating its meaning into a single measurable dimension. I present a counterargument to the inferential move of the skeptic by revealing how it stands on two unstated premises, namely a (...) reflective view of measurements and the unidirectional dynamics between definitional and measurement practices, and corollary assumptions. These premises and assumptions are misaligned with a richer theoretical understanding of measurement and are sometimes inconsistent with how science operates. A more nuanced view of measurement could better explain measurement proliferation while being consistent with new ways in which the general biodiversity concept could be useful. To conclude, I urge philosophers of measurement and conceptual engineers to collaborate in tackling the interplay between conceptual change and measurement practices. (shrink)

I propose a version of teleosemantics for simple animal representations that combines Millikan’s suggestion that they represent the most crucial “normal conditions” required for them to bring about their beneficial behavioral effects with Neander’s suggestion that they represent their “normal causes”. The content of a simple representation is the most crucial among the normal conditions responsible for its tokens having beneficial behavioral effects that also causes such tokens. I argue that this version delivers more plausible contents than other versions of (...) teleosemantics. Frogs’ prey detectors represent the animals they prey on rather than nutritious or small moving things. (shrink)

Shared intentionality is key for understanding human cooperation and cognition. This paper proposes a new way of looking at shared intentionality as a set of interconnected threshold traits, highlighting the role of developmental niche construction in its evolution. This perspective suggests that shared intentionality may have arisen from environmental changes and interactions influencing existing traits, rather than genetic variation for novel cognitive machinery.

In 1899, the first cases of plague were recognised in Paraguay and a few months later in Buenos Aires as part of the third plague pandemic. In the first decades of the twentieth century, plague slowly advanced towards the Argentinian hinterland. In this paper we focus on the production of scientific knowledge about plague in Argentina, where a core of bacteriologists emerged early on. We show how they not only played a central role in the complex process of plague recognition (...) and intervention, but also influenced the scientific development of bacteriology in Argentina and potentially in South America. We argue that bacteriology became a key tool in articulating the promises of modern science with political and economic interests, allowing the Argentinian government to extend its territorial control over Buenos Aires and the hinterland. This can be seen in two different configurations of the plague as an epistemic and political object in Argentina. In the first period, from 1899 to 1910, plague was a problem linked to the ports. In this section of the article, we show how plague became an important issue in the development of bacteriology in Argentina, how this research contributed to new intervention measures and, in some cases, developed innovative ideas about serotherapeutic treatments and the characteristics of the disease. In the second period, from the mid-1910s until the 1940s, research in Argentina provided new evidence of the ‘rural’ nature of plague, a process in deep dialogue with research on plague among peri-domestic and wild rodents carried out in other parts of the Americas, Europe and Africa. This article thus aims to contribute to a history of bacteriology that highlights the role of non-European centres, like Argentina, in the production and circulation of bacteriological knowledge. (shrink)

We present a case study of two scientific perspectives on the phenomenon of nerve signal propagation, a bio-electric and a thermodynamic perspective, and compare this case with two accounts of scientific perspectivism: those of Michela Massimi and Juha Saatsi, respectively. We demonstrate that the interaction between the bio-electric perspective and the thermodynamic perspective can be captured in Saatsi’s terms of progress in explanatory understanding. Using insights from our case study, we argue that both the epistemic and pragmatic dimensions of scientific (...) understanding are important for increasing explanatory understanding of phenomena. The epistemic dimension of understanding is important for increasing the number of actually answered what-if-things-had-been-different questions about a phenomenon, the pragmatic dimension for pointing out the potentially answerable what-if questions that have been overlooked or purposefully neglected thus far. Exposing the limitations of the acquired understanding within a particular perspective can be achieved by criticizing the assumptions that have been adopted to make models of the perspective intelligible, but that are considered problematic from a rival perspective. (shrink)

The emergence of new techniques in both microbial biotechnology and artificial intelligence (AI) is opening up a completely new field for monitoring and sometimes even controlling the evolution of pathogens. However, the now famous generative AI extracts and reorganizes prior knowledge from large datasets, making it poorly suited to making predictions in an unreliable future. In contrast, an unfamiliar perspective can help us identify key issues related to the emergence of new technologies, such as those arising from synthetic biology, whilst (...) revisiting old views of AI or including generative AI as a generator of abduction as a resource. This could enable us to identify dangerous situations that are bound to emerge in the not-too-distant future, and prepare ourselves to anticipate when and where they will occur. Here, we emphasize the fact that amongst the many causes of pathogen outbreaks, often driven by the explosion of the human population, laboratory accidents are a major cause of epidemics. This review, limited to animal pathogens, concludes with a discussion of potential epidemic origins based on unusual organisms or associations of organisms that have rarely been highlighted or studied. (shrink)

Coarse-grain models are essential to understand the biological function of DNA molecules because the length and time scales of the sequence-dependent physical properties of DNA are often beyond the reach of experimental and all-atom computational methods. Simulating coarse-grain models of DNA, e.g. using Langevin dynamics, requires the parametrization of both potential and kinetic energy functions. Many studies have shown that the flexibility (i.e., potential energy) of a DNA molecule depends on its sequence. In contrast, little is known about the sequence-dependence (...) of DNA mass parameters required to model its kinetic energy. In this paper, an algebraic expression is derived for the kinetic energy as a function of linear and angular velocities of each DNA base parameterized by its mass, center of mass, and rotational inertia tensor. The parameters of this function are then approximated from a set of fine-grain molecular dynamics simulations representing all combinations of the four DNA base pairs AT, TA, GC, and CG, in different sequence contexts. Compatibility conditions associated with the assumption of each base being modeled as a rigid body were verified to be good approximations. The kinetic parameters were found to be significantly different between the four G, C, A, and T bases, and to not be dependent on the sequence context. This suggests that the effective kinetic parameters of a DNA base may depend only on the base itself, not on its neighbors. (shrink)

“The Strategy of Model Building in Population Biology” published by Richard Levins in 1966 has been cited over 2500 times. For a paper concerned with modeling approaches in population biology a surprisingly large part of the attention. The Strategy received comes from history and philosophy of biology, and specifically from accounts on model and model formulation. The Strategy is an unusual paper; it presents neither new data nor a new formal model; at times it reads like a manifesto for some (...) modeling approach, without specifying which broader program that approach intends to support. When these peculiarities of The Strategy are even mentioned, the philosophical literature tends to explain them away by invoking Levins’ Marxist commitments. In contrast, I argue that those peculiarities can be explained by examining the programmatic purpose of the paper; starting from his doctoral work, Levins was trying to establish a research program meant to account for the relations between fitness and environment in different terms than the prevalent lock-and-key view. My paper brings that program back to the discussion, explains its relation to competing approaches and examines Levins’ approach to modeling in light of that context. (shrink)

The present article examines the material, epistemological, and social dimensions of late nineteenth-century anti-cholera serum controversies that unfolded in Tokyo and Berlin. It seeks to shed light on the conflicting values embedded in the construction of scientific evidence during the transnational exploration of bacteriology as an effective response to controlling epidemics. Driven by Japanese health authorities’ initiatives, Japanese bacteriologist Kitasato Shibasaburo participated in the elaboration of bacteriological research oriented toward therapeutic application during his stay in Berlin. This work coincided with (...) the rise of a controversy over anti-cholera serum in relation to the animal experiments conducted by Richard Pfeiffer, a German bacteriologist. After presenting a series of animal experiments and certain clinical cases conducted in Germany, France, and Egypt in the context of the controversies, the article analyzes a therapeutic trial conducted by Kitasato in Japan during an 1895 cholera epidemic. His strategy, bringing new data to the transnational debate through an intensive investment of resources in the trial, provoked criticism from his Japanese and German colleagues. These critics questioned Kitasato’s method and pointed out the low social value of this experimental serum therapy, performed in highly equipped conditions. Through this case study, the present article highlights: a) a strong tension between transnational research interactions among bacteriologists and local medical practices during public health campaigns against epidemics at the turn of the twentieth century; b) the importance of analyzing the interconnected effects of local, national and transnational frameworks of medical science when examining the increasingly intertwined relationships between laboratory science and clinical medicine. (shrink)

Despite the encyclopedic knowledge accumulated in contemporary biology, it is still frustratingly elusive to find an uncontroversial answer to the (apparently) simple question, “What are living beings?” Since the traditional approach to answering this question has been by means of definitions, it has been pointed out that an alternative might be to change the strategy and, following the example of other sciences, try to find not a definition but a theoretical identity for living beings. However, according to some critics, such (...) a move is neither possible nor advisable since current biology, limited to only earthly samples of life, does not have enough empirical basis and theoretical development to formulate a theoretical identity for living beings. In this paper, contrary to this diagnosis, I make room for and propose a theoretical identity statement for living beings. First, I argue that the limitations to proposing such an identity are not as severe as it is assumed. Second, I suggest answering the question, “What are living beings?” with the theoretical identity statement, ‘Living beings are exoautopoietic bodies.’ I explain this proposal’s theoretical grounds and defend it against potential objections. (shrink)

Accurate prediction of epidemic evolution faces challenges such as understanding disease dynamics and inadequate epidemiological data. A recent approach faced these issues by modeling susceptible-infectious-susceptible (SIS) dynamics based on the first two statistical moments. Here, we improve this approach by including finite-size populations and analyzing the stability of the resulting model. Results underscore the influence of uncertainties and population size in the natural history of the epidemic.

In this article, I demonstrate two ways in which our major theories of the evolution of cooperation may fail to capture particular social phenomena. The first shortcoming of our current major theories stems from the possibility of mischaracterizing the cooperative problem in game theory. The second shortcoming of our current major theories is the insensitivity of these explanatory models to ecological and genomic context. As a case study to illustrate these points, I will use the cooperative interaction of a species (...) of myxobacteria called Myxococcus xanthus. M. xanthus cooperate in many areas of their life cycle—in quorum sensing, social motility, fruiting body formation, and predation. I focus in particular on predation as we have not yet discovered an adequate explanation of how they sustain cooperative predation in the face of developmental cheats. In explaining why we have not, I draw generalizable conclusions that shed light on our use of simplified models to explain real-world behaviors in a variety of organisms. (shrink)