•  9
    This article argues that a core area of the philosophy of biology—the philosophy of fitness—has for decades rested on fundamental conceptual and mathematical errors. These errors have been leveraged to support the position in the philosophy of biology known as statisticalism, which holds that biological fitness does not cause evolution, but is merely a kind of statistical summary of evolutionary outcomes. This is opposed to causalism, which holds that fitness is based on (causally efficacious) p…Read more
  •  51
    Multilevel innovativeness and cross-species comparisons
    European Journal for Philosophy of Science 15 (3): 1-25. 2025.
    Behavioral innovativeness—the propensity of an individual organism or higher group to innovate—is frequently invoked as a measurable trait allowing for cross-species comparisons. Individuals or species are often regarded as more innovative or less innovative than others, implying that we can rank order the degree of innovativeness along a single dimension. This paper defends a novel multidimensional understanding of behavioral innovativeness in which innovativeness can be modulated with respect …Read more
  •  309
    Tool Use Beyond Humans
    Philosophy of Science 883-899. 2025.
    The definition of tool use has long been debated, especially beyond humans. Recent work argues that the phenomena included within tool use are so broad and varied that there is little hope of using the category for scientific generalizations, explanations, and predictions about the evolution, ecology, and psychology of tool users. One response to this argument has been the development of tooling as a replacement for tool use. In this article, we analyze the tool use and tooling frameworks. Ident…Read more
  •  45
    What is a trait? Lessons from the human chin
    Journal of Experimental Zoology Part B: Molecular and Developmental Evolution 342. 2024.
  •  563
    Driftability and niche construction
    Synthese 204 (6): 1-22. 2024.
    Niche construction is the process of organisms changing themselves or their environment—or their relationship with their environment—in ways that affect the evolutionary trajectory of their population. These evolutionary trajectory changes are traditionally understood to be triggered by changes in selection pressures. Niche construction thus necessarily involves organisms altering selection pressures. In this paper, we argue that changes in selection pressures is not the only way organisms can i…Read more
  •  614
    Cell Fate: What’s Evolution Got to Do With It?
    with Pierre M. Durand
    Yale Journal of Biology and Medicine 96 (4). 2023.
    Theoretical frameworks concerning cell fate typically center on proximate causes to explain how cells know what type they are meant to become. While major advances in cell fate theory have been achieved by these mechanism-focused frameworks, there are some aspects of cell decision-making that require an evolutionary interpretation. While mechanistic biologists sometimes turn to evolutionary theory to gain insights about cell fate (cancer is a good example), it is not entirely clear in cell fate …Read more
  •  105
    Explanatory gaps in evolutionary theory
    Biology and Philosophy 39 (5): 1-18. 2024.
    Proponents of the extended evolutionary synthesis have argued that there are explanatory gaps in evolutionary biology that cannot be bridged by standard evolutionary theory. In this paper, we consider what sort of explanatory gaps they are referring to. We outline three possibilities: data-based gaps, implementation-based gaps, and framework-based gaps. We then examine the purported evolutionary gaps and attempt to classify them using this taxonomy. From there we reconsider the significance of t…Read more
  •  74
    What is a trait? Lessons from the human chin
    Journal of Experimental Zoology B 342 (2). 2024.
    The chin, a distinguishing feature of Homo sapiens, has sparked ongoing debates regarding its evolutionary origins and adaptive significance. We contend that these controversies stem from a fundamental disagreement about what constitutes a well-defined biological trait, a problem that has received insufficient attention despite its recognized importance in biology. In this paper, we leverage paleoanthropological research on the human chin to investigate the general issue of character or trait id…Read more
  •  730
    Claims that our species is an “evolutionary success” typically do not feature prominently in academic articles. However, they do seem to be a recurring trope in science popularization. Why do we seem to be attracted to viewing human evolution through the lense of “success”? In this chapter we discuss how evolutionary success has both causal-descriptive and ethical-normative components, and how its ethical status is ambiguous, with possible hints of anthropocentrism. We also place the concept of …Read more
  •  663
    The developmental properties of organisms play important roles in the generation of variation necessary for evolutionary change. But how can individual development steer the course of evolution? To answer this question, we introduce developmental channeling as a disposition of individual organisms that shapes their possible developmental trajectories and evolutionary dappling as an evolutionary outcome in which the space of possible organismic forms is dappled—it is only partially filled. We the…Read more
  •  35
    What is human nature for?
    In Agustin Fuentes & Aku Visala (eds.), Verbs, Bones, and Brains: Interdisciplinary Perspectives on Human Nature, University of Notre Dame Press. 2016.
    During the battle of Iwo Jima in June 1944, Private First Class Jackylin Harold Lucas and three other U.S. Marines came under attack while making their way along a ravine. Upon seeing two grenades thrown near the soldiers, Lucas dove onto one grenade and pulled the other under his body, saving his companions from serious injury or death. Lucas survived, but his injuries were so grave that his companions left him for dead. Lucas’s act was one of spectacular and nearly suicidal altruism. What does…Read more
  •  745
    Human Nature
    Cambridge University Press. 2023.
    Human nature is frequently evoked to characterize our species and describe how it differs from others. But how should we understand this concept? What is the nature of a species? Some take our nature to be an essence and argue that because humans lack an essence, they also lack a nature. Others argue for non-essentialist ways of understanding human nature, which usually aim to provide criteria for sorting human traits into one of two bins, the one belonging to our nature and the other outside ou…Read more
  •  977
    The concepts and origins of cell mortality
    History and Philosophy of the Life Sciences 45 (23): 1-23. 2023.
    Organismal death is foundational to the evolution of life, and many biological concepts such as natural selection and life history strategy are so fashioned only because individuals are mortal. Organisms, irrespective of their organization, are composed of basic functional units—cells—and it is our understanding of cell death that lies at the heart of most general explanatory frameworks for organismal mortality. Cell death can be exogenous, arising from transmissible diseases, predation, or othe…Read more
  •  53
    What does it mean for our species—or for any species—to be successful? Human Success: Evolutionary Origins and Ethical Implications examines the concept of human success from a variety of disciplinary perspectives, with contributions from leading paleobiologists, anthropologists, geologists, philosophers of science, and ethicists. It tells the tale of how the human species grew in success-linked metrics, such as population size and geographical range, and how it came to dominate ecological syste…Read more
  •  78
    Adaptationism and trait individuation
    Philosophy of Science 90. 2023.
    Adaptationism is often taken to be the thesis that most traits are adaptations. In order to assess this thesis, it seems we must be able to establish either an exhaustive set of all traits or a representative sample of this set. Either task requires a more systematic and principled way of individuating traits than is currently available. Moreover, different trait individuation criteria can make adaptationism turn out true or false. For instance, individuation based on natural selection may rende…Read more
  •  118
    Trait bin and trait cluster accounts of human nature
    In Elizabeth Hannon & Tim Lewens (eds.), Why We Disagree About Human Nature, Oxford University Press. pp. 40-57. 2018.
    Conceptions of human nature fall under two broad categories, trait bin accounts and trait cluster accounts. Trait bin accounts take there to be a special bin of traits, one composed of all and only those traits constituting our nature. For those arguing for a trait bin account of human nature, the challenge is to articulate what it is that marks a trait as being in or outside of the bin. For some, the bin is filled by the traits essential to being human. Others, such as Machery in his contributi…Read more
  •  45
    Millions of scientific articles are published each year, making it difficult to stay abreast of advances within even the smallest subdisciplines. Traditional approaches to the study of science, such as the history and philosophy of science, involve closely reading a relatively small set of journal articles. And yet many questions benefit from casting a wider net: Is most scientific change gradual or revolutionary? What are the key sources of scientific novelty? Over the past several decades, a m…Read more
  •  2
    Programmed cell death as a black queen in microbial communities
    with Andrew Ndhlovu and Pierre M. Durand
    Molecular Ecology 30 1110-1119. 2021.
    Programmed cell death (PCD) in unicellular organisms is in some instances an altruistic trait. When the beneficiaries are clones or close kin, kin selection theory may be used to explain the evolution of the trait, and when the trait evolves in groups of distantly related individuals, group or multilevel selection theory is invoked. In mixed microbial communities, the benefits are also available to unrelated taxa. But the evolutionary ecology of PCD in communities is poorly understood. Few hypot…Read more
  •  114
    The proximate-ultimate distinction and the active role of the organism in evolution
    with Bendik Hellem Aaby
    Biology and Philosophy 37 (4): 1-20. 2022.
    The validity and utility of the proximate-ultimate distinction in biology have recently been under debate. Opponents of the distinction argue that it rules out individual-level organismic processes from evolutionary explanations, thereby leading to an unfounded separation between organismic (developmental, behavioral, etc.) causation and evolutionary causation. Proponents of the proximate-ultimate distinction, on the other hand, argue that it serves an important epistemological role in forming d…Read more
  •  1107
    What Are the ‘Levels’ in Levels of Selection?
    with Markus I. Eronen
    British Journal for the Philosophy of Science 76 (2): 495-518. 2025.
    The levels of selection debate is generally taken to be a debate about how natural selection can occur at the various levels of biological organization. In this paper, we argue that questions about levels of selection should be analyzed separately from questions about levels of organization. In the deflationary proposal we defend, all that is necessary for multilevel selection is that there are cases in which particles are nested in collectives, and that both the collectives and the particles th…Read more
  •  211
    Empathy and the Evolutionary Emergence of Guilt
    Philosophy of Science 89 (3): 434-453. 2022.
    Guilt poses a unique evolutionary problem. Unlike other dysphoric emotions, it is not immediately clear what its adaptive significance is. One can imagine thriving despite or even because of a lack of guilt. In this article, we review solutions offered by Scott James, Richard Joyce, and Robert Frank and show that although their solutions have merit, none adequately solves the puzzle. We offer an alternative solution, one that emphasizes the role of empathy and posttransgression behavior in the e…Read more
  •  80
    Organisms, Traits, and Population Subdivisions: Two Arguments against the Causal Conception of Fitness?
    British Journal for the Philosophy of Science 64 (3): 589-608. 2013.
    A major debate in the philosophy of biology centers on the question of how we should understand the causal structure of natural selection. This debate is polarized into the causal and statistical positions. The main arguments from the statistical side are that a causal construal of the theory of natural selection's central concept, fitness, either (i) leads to inaccurate predictions about population dynamics, or (ii) leads to an incoherent set of causal commitments. In this essay, I argue that n…Read more
  •  167
    What is animal culture?
    In Kristin Andrews & Jacob Beck (eds.), The Routledge Handbook of Philosophy of Animal Minds, Routledge. 2017.
    Culture in humans connotes tradition, norms, ritual, technology, and social learning, but also cultural events like operas or gallery openings. Culture is in part about what we do, but also sometimes about what we ought to do. Human culture is inextricably intertwined with language and much of what we learn and transmit to others comes through written or spoken language. Given the complexities of human culture, it might seem that we are the only species that exhibits culture. How, then, are we t…Read more
  •  170
    In this paper, we distinguish two different approaches to cultural evolution. One approach is meme-centered, the other organism-centered. We argue that in situations in which the meme- and organism-centered approaches are competing alternatives, the organism-centered approach is in many ways superior. Furthermore, the organism-centered approach can go a long way toward understanding the evolution of institutions. Although the organism-centered approach is preferable for a broad class of situatio…Read more
  •  30
    Recolonization of bigleaf maple branches by epiphytic bryophytes following experimental disturbance
    with Alexander Cobb, Nalini Nadkarni, and Abraham Svoboda
    Canadian Journal of Botany 79 (1): 1-8. 2001.
    The dynamics of epiphytic bryophyte communities following natural and human disturbance have rarely been quantified. We describe the response of bryophyte communities on bigleaf maple trees in Olympia, Washington, following their experimental removal. Approximately 8% of the exposed area was recolonized by bryophytes 1 year after clearing, and 27% after 3 years. Lateral encroachment from bryophytes on the sides of the 20-cm-long plots accounted for 75% of this recolonization, with growth from re…Read more
  •  239
    Block Fitness
    Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 37 (3): 484-498. 2006.
    There are three related criteria that a concept of fitness should be able to meet: it should render the principle of natural selection non-tautologous and it should be explanatory and predictive. I argue that for fitness to be able to fulfill these criteria, it cannot be a property that changes over the course of an individual's life. Rather, I introduce a fitness concept--Block Fitness--and argue that an individual's genes and environment fix its fitness in such a way that each individual's fit…Read more
  •  249
    Can altruism be unified?
    Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences 56. 2016.
    There is clearly a plurality of forms of altruism. Classically, biological altruism is distinguished from psychological altruism. Recent discussions of altruism have attempted to distinguish even more forms of altruism. I will focus on three altruism concepts, biological altruism, psychological altruism, and helping altruism. The questions I am concerned with here are, first, how should we understand these concepts? and second, what relationship do these concepts bear to one another? In particul…Read more
  •  161
    Three Kinds of Niche Construction
    British Journal for the Philosophy of Science 73 (2): 351-372. 2022.
    Niche construction theory concerns how organisms can change selection pressures by altering the feature–factor relationship between themselves and their environment. These alterations are standardly understood to be brought about through two kinds of organism–environment interaction: perturbative and relocational niche construction. We argue that a reconceptualization is needed on the grounds that if a niche is understood as the feature–factor relationship, then there are three fundamental ways …Read more
  •  1549
    Causal Inference from Noise
    Noûs 55 (1): 152-170. 2021.
    "Correlation is not causation" is one of the mantras of the sciences—a cautionary warning especially to fields like epidemiology and pharmacology where the seduction of compelling correlations naturally leads to causal hypotheses. The standard view from the epistemology of causation is that to tell whether one correlated variable is causing the other, one needs to intervene on the system—the best sort of intervention being a trial that is both randomized and controlled. In this paper, we argue t…Read more
  •  179
    The Nature of Programmed Cell Death
    Biological Theory 14 (1): 30-41. 2019.
    In multicellular organisms, cells are frequently programmed to die. This makes good sense: cells that fail to, or are no longer playing important roles are eliminated. From the cell’s perspective, this also makes sense, since somatic cells in multicellular organisms require the cooperation of clonal relatives. In unicellular organisms, however, programmed cell death poses a difficult and unresolved evolutionary problem. The empirical evidence for PCD in diverse microbial taxa has spurred debates…Read more