In plant morphology, most structures of vascular plants can easily be assigned to pre-established organ categories. However, there are also intermediate structures that do not fit those categories associated with a classical approach to morphology. To integrate the diversity of forms in the same general framework, we constructed a theoretical morphospace based on a variety of modalities where it is possible to calculate the morphological distance between plant organs. This paper gives emphasis on shoot, leaf, leaflet and trichomes while ignoring (...) the root. This will allow us to test the hypothesis that classical morphology (typology) and dynamic morphology occupy the same theoretical morphospace and the relationship between the two approaches remains a question of weighting of criteria. Our approach considers the shoot (i.e. leafy stem) as the basic morphological structural unit. A theoretical data table consisting of as many lines as there are possible combinations between different modalities of characters of a typical shoot was generated. By applying a principal components analysis (PCA) to these data it is possible to define a theoretical morphospace of shoots. Typical morphological elements (shoots, leaves, trichomes) and atypical structures (phylloclades, cladodes) including particular cases representing ‘exotic’ structures such as the epiphyllous appendages of Begonia and ‘water shoot’ and ‘leaf’ of aquatic Utricularia were placed in the morphospace. The more an organ differs from a typical shoot, the further away it will be from the barycentre of shoots. By giving a higher weight to variables used in classical typology, the different organ categories appear to be separate, as expected. If we do not make any particular arbitrary choice in terms of character weighting, as it is the case in the context of dynamic morphology, the clear separation between organs is replaced by a continuum. Contrary to typical structures, “intermediate” structures are only compatible with a dynamic morphology approach whether they are placed in the morphospace based on a ponderation compatible with typology or dynamic morphology. The difference in points of view between typology and continuum leads to a particular mode of weighting. By using an equal weighting of characters, contradictions due to the ponderation of characters are avoided, and the morphological concepts of continuum’ and ‘typology’ appear as sub-classes of ‘process’ or ‘dynamic morphology’. (shrink)

Agnes Arber (1879-1960) was a British botanist who was a leading plant morphologist during the first half of the 20th century. She also wrote on the history and philosophy of botany. I argue in this article that her philosophical work on form and on how the work of the mind and the eye relate to each other in morphological research are relevant to the science of today. Arber's unusual blend of interests - in botany, history, philosophy, and art - put (...) her in a unique position to examine issues of form. Even her unorthodox ideas on evolution can now be seen as fitting in well with discussions of natural selection as the predominant engine of evolutionary change. Arber's views also throw light on present work dealing with developmental plant genetics and with the study of protein form. I will further argue that her marginal position relative to institutional science, while it may have left her vulnerable to criticism, also made possible her deep philosophical reflections on morphology. (shrink)

Since its appearance, Evolutionary Developmental Biology (EvoDevo) has been called an emerging research program, a new paradigm, a new interdisciplinary field, or even a revolution. Behind these formulas, there is the awareness that something is changing in biology. EvoDevo is characterized by a variety of accounts and by an expanding theoretical framework. From an epistemological point of view, what is the relationship between EvoDevo and previous biological tradition? Is EvoDevo the carrier of a new message about how to conceive evolution (...) and development? Furthermore, is it necessary to rethink the way we look at both of these processes? EvoDevo represents the attempt to synthesize two logics, that of evolution and that of development, and the way we conceive one affects the other. This synthesis is far from being fulfilled, but an adequate theory of development may represent a further step towards this achievement. In this article, an epistemological analysis of EvoDevo is presented, with particular attention paid to the relations to the Extended Evolutionary Synthesis (EES) and the Standard Evolutionary Synthesis (SET). (shrink)

Recent and ongoing debates in biology and in the philosophy of biology reveal widespread dissatisfaction with the current definitions or circumscriptions, which are often vague or controversial, of key concepts such as the gene, individual, species, and homology, and even of whole disciplinary fields within the life sciences. To some extent, the long growing awareness of these conceptual issues and the contrasting views defended in their regard can be construed as a symptom of the need to revisit traditional unchallenged partitions (...) between the specialist disciplines within the life sciences. I argue here that the current relationships between anchor disciplines (e.g., developmental biology, evolutionary biology, biology of reproduction) and nomadic concepts wandering between them is worth being explored from a reciprocal perspective, by selecting suitable anchor concepts around which disciplinary fields can flexibly move. Three examples are offered, focusing on generalized anchor concepts of generation (redefined in a way that suggests new perspectives on development and reproduction), organizational module (with a wide-ranging domain of application in comparative morphology, developmental biology, and evolutionary biology) and species as unit of representation of biological diversity (suggesting a taxonomic pluralism that must be managed with suitable adjustments of current nomenclature rules). (shrink)

None of the concepts thus far advanced by biologists or philosophers of life covers in a satisfactory way all instances and aspects of biological individuality. Two main, only partially overlapping notions must be distinguished: physiological individuality, based on morphological or molecular attributes, and evolutionary individuality, based on the uniqueness of the role played by the individual in evolutionary processes. The three individuality criteria suggested by Pradeu, i.e. uniqueness, delineation and persistence, are useful as a rough guide, but their application faces (...) serious problems or limitations, e.g. with polygenomic organisms or polyembryonic metazoans. Persistence of individuality throughout development deserves accurate revisitation. (shrink)

Biological diversity (BD) explored by biological systematics is a complex yet organized natural phenomenon and can be partitioned into several aspects, defined naturally with reference to various causal factors structuring biota. These BD aspects are studied by particular research programs based on specific taxonomic theories (TTs). They provide, in total, a framework for comprehending the structure of biological systematics and its multi-aspect relations to other fields of biology. General principles of individualizing BD aspects and construing TTs as quasi-axiomatics are briefly (...) considered. It is stressed that each TT is characterized by a specific combination of interrelated ontological and epistemological premises most adequate to the BD aspect a TT deals with. The following contemporary research programs in systematics are recognized and characterized in brief: phenetic, rational (with several subprograms), numerical, typological (with several subprograms), biosystematic, biomorphic, phylogenetic (with several subprograms), and evo-devo. From a scientific pluralism perspective, all of these research programs, if related to naturally defined particular BD aspects, are of the same biological and scientific significance. They elaborate “locally” natural classifications that can be united by a generalized faceted classification. (shrink)

This paper addresses the role of time scales in conceptualizing biological hierarchies. So far, the concept of hierarchies in philosophy of science has been dominated by the idea of composition and parthood, respectively. However, this view does not exhaust the diversity of hierarchical descriptions in the biosciences. Therefore, we highlight a type of hierarchy usually overlooked by philosophers of science. It distinguishes processes based on the different time scales (i.e. rates, frequencies, and rhythms) on which they occur. These time scale (...) hierarchies often are connected with assumptions defended in process ontology. Due to their ability to describe interlevel dynamics of various kinds, we call these hierarchies ‘dynamic hierarchies.’ In order to highlight and discuss their organization, explanatory roles, and epistemic virtues we focus on dynamic hierarchies in developmental biology and evolutionary developmental biology (evo-devo). In these fields, dynamic hierarchies offer crucial complementary information to descriptions of compositional hierarchies. (shrink)

The definition of biological individuality is one of the most discussed topics in philosophy of biology, but current debate has focused almost exclusively on evolution-based accounts. Moreover, several participants in this debate consider the notions of a biological individual and an organism as equivalent. In this paper, I show that the debates would be considerably enriched and clarified if philosophers took into account two elements. First, physiological fields are crucial for the understanding of biological individuality. Second, the category of biological (...) individuals should be divided into two subcategories: physiological individuals and evolutionary individuals, which suggests that the notions of organism and biological individual should not be used interchangeably. I suggest that the combination of an evolutionary and a physiological perspective will enable biologists and philosophers to supply an account of biological individuality that will be both more comprehensive and more in accordance with scientific practices. (shrink)

This edited volume focuses on the hypothesis that performativity is not a property confined to certain specific human skills, or to certain specific acts of language, nor an accidental enrichment due to creative intelligence. Instead, the executive and motor component of cognitive behavior should be considered an intrinsic part of the physiological functioning of the mind, and as endowed with self-generative power. Performativity, in this theoretical context, can be defined as a constituent component of cognitive processes. The material action allowing (...) us to interact with reality is both the means by which the subject knows the surrounding world and one through which he experiments with the possibilities of his body. This proposal is rooted in models now widely accepted in the philosophy of mind and language; in fact, it focuses on a space of awareness that is not in the individual, or outside it, but is determined by the species-specific ways in which the body acts on the world. This theoretical hypothesis will be pursued through the latest interdisciplinary methodology typical of cognitive science, that coincide with the five sections in which the book is organized: Embodied, enactivist, philosophical approaches; Aesthetics approaches; Naturalistic and evolutionary approaches; Neuroscientific approaches; Linguistics approaches. This book is intended for: linguists, philosophers, psychologists, cognitive scientists, scholars of art and aesthetics, performing artists, researchers in embodied cognition, especially enactivists and students of the extended mind. (shrink)

A un secolo e mezzo dalla pubblicazione dell'Origine delle specie, la nozione di omologia di Owen, che implica che due organi o due funzioni a confronto possono essere riconosciuti come “la stessa cosa” continua a dominare gli attuali approcci al problema dell’omologia. L'idea che i caratteri possano “rimanere se stessi” attraverso un numero indefinito (anche se finito) di stati alternativi che si susseguono nel corso dell'evoluzione è probabilmente basato su un'interpretazione idealistica di come gli organismi si evolvono. Se si dà (...) per scontata l'esistenza di caratteristiche del corpo che conservano la loro identità nel cambiamento, l'esistenza di omologhi può essere spiegata (i) in termini di leggi universali della forma, magari nella forma moderna dello strutturalismo di processo, o (ii) come il prodotto di discendenza comune, o (iii) in termini di cause prossime responsabili della comparsa di moduli di sviluppo conservati. Tuttavia, leggendo la storia della vita attraverso la lente dell’evoluzione, appare molto problematico descrivere un organismo come una somma di caratteri che, una volta apparsi come novità evolutive, rimangono poi come unità costruttive essenzialmente immutabili tra le quali possiamo predicare (o negare) omologia. Tutti i tratti sono meglio interpretati come incroci complessi e mutevoli di un numero indeterminato di elementi e dei processi che li modellano nel corso dell’ontogenesi e della filogenesi. Di conseguenza, appare raccomandabile un approccio fattoriale, o combinatorio, all’omologia. (shrink)