The development of cognitive capacities depends on environmental conditions, including various forms of scaffolding. As a result, the evolution of cognition depends on the evolution of activities that provide scaffolding for cognitive development. Non-human animals reared and trained in environments heavily scaffolded with human social interaction can acquire non-species-typical knowledge, skills, and capacities. This can potentially shed light on some of the changes that paved the way for the evolution of distinctively human behavioral capacities such as language, advanced social cognition, (...) and elaborate forms of tool craft. In this light, I revisit several widely known—but also widely misunderstood—cases of exceptional animals and argue that each of these cases provides clues about key innovations in our own evolutionary history. (shrink)

Taking Chomsky’s Syntactic Structures as a starting point, this paper explores the use of recursive techniques in contemporary linguistic theory. Specifically, it is shown that there were profound ambiguities surrounding the notion of recursion in the 1950s, and that this was partly due to the fact that influential texts such as Syntactic Structures neglected to define what exactly constituted a recursive device. As a result, uncertainties concerning the role of recursion in linguistic theory have prevailed until the present day, and (...) some of the most common misunderstandings that have appeared in recent discussions are examined at some length. This article shows that debates about such topics are frequently undermined by fundamental misunderstandings concerning core terminology, and the full extent of the prevailing haziness is revealed. An attempt is made, for instance, to distinguish between such things as iterative constructional devices and self-similar syntactic embedding, despite the fact that these are usually both unhelpfully classified as examples of recursion. Consequently, this article effectively constitutes a plea for much greater accuracy and clarity when such important issues are addressed from a linguistic perspective. (shrink)

A Darwinian theory of the evolution of language must be incremental: to explain the transition from a hominin baseline with great ape grade communicative capacities to language-equipped hominins as a series of small steps. This paper takes up that project for the special case of words, giving an incremental model of the call to word transition. The model is embedded in a general conception of human social evolution with independent empirical support, but it also depends on some more specific assumptions (...) about language and about the earlier forms of hominin communication. Given these assumptions, the paper can be no more than a working draft of a more complete theory. (shrink)

Since the publication of Fodor's (1983) The Modularity of Mind, there have been quite a few discussions of cognitive modularity among cognitive scientists. Generally, in those discussions, modularity means a property of specialized cognitive processes or a domain-specific body of information. In actuality, scholars understand modularity in many different ways. Different characterizations of modularity and modules were proposed and discussed, but they created misunderstanding and confusion. In this article, I classified and analyzed different approaches to modularity and argued for the (...) unity of modularity. Modularity is a multidimensional property consisting of features from several dimensions specifying different aspects of cognition. Among those, there are core features of modularity, and these core features form a cross-dimensional unity. Despite the diverse and liberal characterizations, modularity contributes to cognitive science because of the unity of the core features. (shrink)

El pensamiento es incorporado por la articulación de los dos algoritmos: la estructura interna para conocer y la realidad, externa, a ser reconocida. La realidad interna está dada desde la estructura de la lengua, la cual más adelante dará lugar a un formato lógica-matemática. La realidad externa, que es también antropológica, está mediada por las áreas somatosensoriales cerebrales, que protológicamente acercan a lo distinto del humano. La filosofía y la ciencia tienen la tarea de acercarse a estas realidades para enhebrarlas, (...) de lo cual resulta un conocimiento general y una ciencia epistemológicamente bien fundada, puesto que hay una estructura ontológica y lógica que les da razón. Desde este fundamento no resultan bien libradas ni el empirismo ni es racionalismo y se abre una ventana para una metafísica menos unilateral y más rigurosa. (shrink)

A number of recent studies have revealed correspondences between song- and language-related neural structures, pathways, and gene expression in humans and songbirds. Analyses of vocal learning, song structure, and the distribution of song elements have similarly revealed a remarkable number of shared characteristics with human speech. This article reviews recent developments in the understanding of these issues with reference to the phonological phenomena observed in human language. This investigation suggests that birds possess a host of abilities necessary for human phonological (...) computation, as evidenced by behavioral, neuroanatomical, and molecular genetic studies. Vocal-learning birds therefore present an excellent model for studying some areas of human phonology, though differences in the primitives of song and language as well as the absence of a human-like morphosyntax make human phonology differ from birdsong phonology in crucial ways. (shrink)

This essay employs Charles Peirce’s triadic semiotics in order to develop a biosemiotic theory of life that is capable of illuminating the function of information in living systems. Specifically, I argue that the relationship between biological information structures , selecting environments, and the adapted bodily processes of living organisms is aptly modelled by the irreducibly triadic relationship between Peirce’s sign, object, and interpretant, respectively. In each instance of information-based semiosis, the information structure is a complex informational sign that represents the (...) informational object ; and the bodily, behavioral, mental, or intellectual processes that are organized by the informational sign to more or less accurately interpret the present environment constitute a complex informational interpretant—a living, interpreting organism. The essay begins by discussing the precise sense in which this biosemiotic theory is based upon Charles Peirce’s semiotic theory. Next, the theory is developed at length in relation to genetic information structures. Finally, I present a brief outline of how the theory applies to neural and linguistic information structures. The essay concludes with a reflection upon the anti-reductionist implications of the theory. (shrink)

We explore the formal foundations of recent studies comparing aural pattern recognition capabilities of populations of human and non-human animals. To date, these experiments have focused on the boundary between the Regular and Context-Free stringsets. We argue that experiments directed at distinguishing capabilities with respect to the Subregular Hierarchy, which subdivides the class of Regular stringsets, are likely to provide better evidence about the distinctions between the cognitive mechanisms of humans and those of other species. Moreover, the classes of the (...) Subregular Hierarchy have the advantage of fully abstract descriptive (model-theoretic) characterizations in addition to characterizations in more familiar grammar- and automata-theoretic terms. Because the descriptive characterizations make no assumptions about implementation, they provide a sound basis for drawing conclusions about potential cognitive mechanisms from the experimental results. We review the Subregular Hierarchy and provide a concrete set of principles for the design and interpretation of these experiments. (shrink)

Primate vocal communication is very different from human language. Differences are most pronounced in call production. Differences in production have been overemphasized, however, and distracted attention from the information that primates acquire when they hear vocalizations. In perception and cognition, continuities with language are more apparent. We suggest that natural selection has favored nonhuman primates who, upon hearing vocalizations, form mental representations of other individuals, their relationships, and their motives. This social knowledge constitutes a discrete, combinatorial system that shares several (...) features with language. It is probably a general primate characteristic whose appearance pre-dates the evolution of spoken language in our hominid ancestors. The prior evolution of social cognition created individuals who were preadapted to develop language. Several features thought to be unique to language—like discrete combinatorics and the encoding of propositional information—were not introduced by language. They arose, instead, because understanding social life and predicting others’ behavior requires a particular style of thinking. (shrink)

Extrapolation from a well-understood base population to a less-understood target population can fail if the base and target populations are not sufficiently similar. Differences between laboratory mice and humans, for example, can hinder extrapolation in medical research. Mice that carry a partial or complete human physiological system, known as humanized mice, are supposed to make extrapolation more reliable by simulating a variety of human diseases. But what justifies our belief that these mice are similar enough to their human counterparts to (...) simulate human disease? I argue that, unless three requirements are met in the process of humanizing mice, very little does. My requirements are not meant to provide necessary and sufficient conditions that guarantee a particular outcome. Instead, they serve as a heuristic for guiding scientific judgments involving extrapolation. In developing each requirement, I engage with philosophical issues concerning the nature of model-based science and the mechanistic approach (and its limits) to making generalizations in the life sciences. (shrink)

In a continuation of the conversation with Fitch, Chomsky, and Hauser on the evolution of language, we examine their defense of the claim that the uniquely human, language-specific part of the language faculty (the “narrow language faculty”) consists only of recursion, and that this part cannot be considered an adaptation to communication. We argue that their characterization of the narrow language faculty is problematic for many reasons, including its dichotomization of cognitive capacities into those that are utterly unique and those (...) that are identical to nonlinguistic or nonhuman capacities, omitting capacities that may have been substantially modified during human evolution. We also question their dichotomy of the current utility versus original function of a trait, which omits traits that are adaptations for current use, and their dichotomy of humans and animals, which conflates similarity due to common function and similarity due to inheritance from a recent common ancestor. We show that recursion, though absent from other animals’ communications systems, is found in visual cognition, hence cannot be the sole evolutionary development that granted language to humans. Finally, we note that despite Fitch et al.’s denial, their view of language evolution is tied to Chomsky’s conception of language itself, which identifies combinatorial productivity with a core of “narrow syntax.” An alternative conception, in which combinatoriality is spread across words and constructions, has both empirical advantages and greater evolutionary plausibility. q 2005 Elsevier B.V. All rights reserved. (shrink)

I argue that linguistic meanings are instructions to build monadic concepts that lie between lexicalizable concepts and truth-evaluable judgments. In acquiring words, humans use concepts of various adicities to introduce concepts that can be fetched and systematically combined via certain conjunctive operations, which require monadic inputs. These concepts do not have Tarskian satisfaction conditions. But they provide bases for refinements and elaborations that can yield truth-evaluable judgments. Constructing mental sentences that are true or false requires cognitive work, not just an (...) exercise of basic linguistic capacities. (shrink)

Absolute linguistic universals are often justified by cross-linguistic analysis: If all observed languages exhibit a property, the property is taken to be a likely universal, perhaps specified in the cognitive or linguistic systems of language learners and users. In many cases, these patterns are then taken to motivate linguistic theory. Here, we show that cross-linguistic analysis will very rarely be able to statistically justify absolute, inviolable patterns in language. We formalize two statistical methods—frequentist and Bayesian—and show that in both it (...) is possible to find strict linguistic universals, but that the numbers of independent languages necessary to do so is generally unachievable. This suggests that methods other than typological statistics are necessary to establish absolute properties of human language, and thus that many of the purported universals in linguistics have not received sufficient empirical justification. (shrink)

In the present study, using event-related functional magnetic resonance imaging, we investigated a group of participants on a grammaticality classification task after they had been exposed to well-formed consonant strings generated from an artificial regular grammar. We used an implicit acquisition paradigm in which the participants were exposed to positive examples. The objective of this studywas to investigate whether brain regions related to language processing overlap with the brain regions activated by the grammaticality classification task used in the present study. (...) Recent meta-analyses of functional neuroimaging studies indicate that syntactic processing is related to the left inferior frontal gyrus (Brodmann's areas 44 and 45) or Broca's region. In the present study, we observed that artificial grammaticality violations activated Broca's region in all participants. This observation lends some support to the suggestions that artificial grammar learning represents a model for investigating aspects of language learning in infants [TICS 4 (2000) 178] and adults [Proceedings of the National Academy of Sciences of United States of America 99 (2002) 529]. (shrink)

In this paper I put forward a thesis regarding the anatomy of “cultural evolution”, in particular the way the “cultural” transmission of behavioral patterns came to piggyback, through us humans, on the transmission effected by genetic evolution. I claim that what grounds and supports this new kind of transmission is a complex behavioral “meta-pattern” that makes it possible to grasp a pattern as something that “ought to be”, i.e. that transforms the pattern into what we can call a rule. (Here (...) I draw especially on the philosophical insights of Wilfrid Sellars.) In this way I interlink empirical research done in evolution theory with some more speculative philosophical theories, thus shedding new light on the former and adding an empirical footing to the latter. (shrink)

Human languages vary in many ways but also show striking cross-linguistic universals. Why do these universals exist? Recent theoretical results demonstrate that Bayesian learners transmitting language to each other through iterated learning will converge on a distribution of languages that depends only on their prior biases about language and the quantity of data transmitted at each point; the structure of the world being communicated about plays no role (Griffiths & Kalish, , ). We revisit these findings and show that when (...) certain assumptions about the relationship between language and the world are abandoned, learners will converge to languages that depend on the structure of the world as well as their prior biases. These theoretical results are supported with a series of experiments showing that when human learners acquire language through iterated learning, the ultimate structure of those languages is shaped by the structure of the meanings to be communicated. (shrink)

Why should music be of interest to cognitive scientists, and what role does it play in human cognition? We review three factors that make music an important topic for cognitive scientific research. First, music is a universal human trait fulfilling crucial roles in everyday life. Second, music has an important part to play in ontogenetic development and human evolution. Third, appreciating and producing music simultaneously engage many complex perceptual, cognitive, and emotional processes, rendering music an ideal object for studying the (...) mind. We propose an integrated status for music cognition in the Cognitive Sciences and conclude by reviewing challenges and big questions in the field and the way in which these reflect recent developments. (shrink)

Umerez’s analysis made me aware of the fundamental differences in the culture of physics and molecular biology and the culture of semiotics from which the new field of biosemiotics arose. These cultures also view histories differently. Considering the evolutionary span and the many hierarchical levels of organization that their models must cover, models at different levels will require different observables and different meanings for common words, like symbol, interpretation, and language. These models as well as their histories should be viewed (...) as complementary rather than competitive. The relation of genetic language and human language is the central issue. They are separated by 4 billion years and require entirely different models. Nevertheless, these languages have in common a unique unlimited expressive power that allows open-ended evolution and creative thought. Understanding the nature of this expressive power and how it arises remains a basic unsolved problem of biosemiotics. (shrink)

The necessary but not sufficient conditions for biological informational concepts like signs, symbols, memories, instructions, and messages are (1) an object or referent that the information is about, (2) a physical embodiment or vehicle that stands for what the information is about (the object), and (3) an interpreter or agent that separates the referent information from the vehicle’s material structure, and that establishes the stands-for relation. This separation is named the epistemic cut, and explaining clearly how the stands-for relation is (...) realized is named the symbol-matter problem. (4) A necessary physical condition is that all informational vehicles are material boundary conditions or constraints acting on the lawful dynamics of local systems. It is useful to define a dependency hierarchy of information types: (1) syntactic information (i.e., communication theory), (2) heritable information acquired by variation and natural selection, (3) non-heritable learned or creative information, and (4) measured physical information in the context of natural laws. High information storage capacity is most reliably implemented by discrete linear sequences of non-dynamic vehicles, while the execution of information for control and construction is a non-holonomic dynamic process. The first epistemic cut occurs in self-replication. The first interpretation of base sequence information is by protein folding; the last interpretation of base sequence information is by natural selection. Evolution has evolved senses and nervous systems that acquire non-heritable information, and only very recently after billions of years, the competence for human language. Genetic and human languages are the only known complete general purpose languages. They have fundamental properties in common, but are entirely different in their acquisition, storage and interpretation. (shrink)

Language sciences have long maintained a close and supposedly necessary coupling between the infinite productivity of the human language faculty and recursive grammars. Because of the formal equivalence between recursion and non-recursive iteration; recursion, in the technical sense, is never a necessary component of a generative grammar. Contrary to some assertions this equivalence extends to both center-embedded relative clauses and hierarchical parse trees. Inspection of language usage suggests that recursive rule components in fact contribute very little, and likely nothing significant, (...) to linguistic creativity. Further than this, if the productivity of human language is considered as not rigidly bound, but not infinite, then the need for any sort of iteration in generative grammars vanishes and can be replaced with a Non-iterative Explicit Alternatives Rule grammar. The knock-on effects of dispensing with recursive grammar components are: that language diversity can simply be based on rule and lexicon combinatorics with no potentially infinite dimensions derived from recursive or iterative components of rules; the oddity of a vast, multiply-infinite competence set of ‘grammatical but unacceptable’ productions is gone; and the development of a language faculty based on rules that eschew iterative rule components avoids any need for explaining ‘special’ mechanisms. On the broader front of searching for the mechanisms of mind, our analysis can be similarly applied to the proposals for a recursive basis for mind as an explanation for humanity’s great leap forward. (shrink)

In this model consciousness is a form of memory. We are essentially “living in the past” as our experience, the qualia, is always of past events. Consciousness represents the storage of past events for use in future situations and it is altered by external experience of the organism. Psychological frameworks of conditioning and learning theory are used to explain this model along with recent neuropsychological research on synaesthesia and phantom limb pain. Consciousness results from the gradual evolutionary development of the (...) human information processing function. Language is hypothesised to have evolved at a pre-conscious stage of human development as a function of the need for ‘within-organism’ data storage. Communication with others may not have been the initial evolutionary advantage conferred by language. The later incidental use of language as a communication tool, which results in the reflecting back of one’s experience through others, is what has triggered a conscious experience. (shrink)

Philosophical theorizing is often, either tacitly or explicitly, guided by intuitions about cases. Theories that accord with our intuitions are generally considered to be prima facie better than those that do not. However, recent empirical work has suggested that philosophically significant intuitions are variable and unstable in a number of ways. This variability of intuitions has led naturalistically inclined philosophers to disparage the practice of relying on intuitions for doing philosophy in general (e.g. Stich & Weinberg 2001) and for doing (...) moral philosophy in particular (Appiah 2008; Doris & Stich 2005; Horowitz 1998; Nadelhoffer & Feltz 2008; Sinnott Armstrong 2008). In this paper, we will draw on naturalistic considerations to offer some solace to philosophers who rely on intuitions. We wouldn’t call this a defense of intuitions, exactly, since we are sympathetic with much of the naturalists’ critique. But we want to introduce into the debate some neglected naturalistic reasons to be optimistic about intuitions, focusing especially on ethical intuitions. (shrink)

Recent research suggests that language evolution is a process of cultural change, in which linguistic structures are shaped through repeated cycles of learning and use by domain-general mechanisms. This paper draws out the implications of this viewpoint for understanding the problem of language acquisition, which is cast in a new, and much more tractable, form. In essence, the child faces a problem of induction, where the objective is to coordinate with others (C-induction), rather than to model the structure of the (...) natural world (N-induction). We argue that, of the two, C-induction is dramatically easier. More broadly, we argue that understanding the acquisition of any cultural form, whether linguistic or otherwise, during development, requires considering the corresponding question of how that cultural form arose through processes of cultural evolution. This perspective helps resolve the “logical” problem of language acquisition and has far-reaching implications for evolutionary psychology. (shrink)

In this paper, I address the issue of scientific modelling in contemporary linguistics, focusing on the generative tradition. In so doing, I identify two common varieties of linguistic idealisation, which I call determination and isolation respectively. I argue that these distinct types of idealisation can both be described within the remit of Weisberg’s :639–659, 2007) minimalist idealisation strategy in the sciences. Following a line set by Blutner :27–35, 2011), I propose this minimalist idealisation analysis for a broad construal of the (...) generative linguistic programme and thus cite examples from a wide range of linguistic frameworks including early generative syntax, Minimalism, the parallel architecture and optimality theory. Lastly, I claim that from a modelling perspective, the dynamic turn in syntax can be explained as a continuation, as opposed to a marked shift, of the generative modelling paradigm. Seen in this light, my proposal is an even broader construal of the generative tradition, along scientific modelling lines. Thus, I offer a lens through which to appreciate the scientific contribution of generative grammar, amid an increased resistance to some of its core theoretical posits, in terms of a brand of structural realism in the philosophy of science and specifically scientific modelling. (shrink)

In this paper, I utilise the growing literature on scientific modelling to investigate the nature of formal semantics from the perspective of the philosophy of science. Specifically, I incorporate the inferential framework proposed by Bueno and Colyvan : 345–374, 2011) in the philosophy of applied mathematics to offer an account of how formal semantics explains and models its data. This view produces a picture of formal semantic models as involving an embedded process of inference and representation applying indirectly to linguistic (...) phenomena. The final aim of the paper is directed at proposing a novel account of the syntax–semantics interface while shedding light on empty categories, semantically null forms, underspecified content and compositionality as a whole. (shrink)

The concept of linguistic infinity has had a central role to play in foundational debates within theoretical linguistics since its more formal inception in the mid-twentieth century. The conceptualist tradition, marshalled in by Chomsky and others, holds that infinity is a core explanandum and a link to the formal sciences. Realism/Platonism takes this further to argue that linguistics is in fact a formal science with an abstract ontology. In this paper, I argue that a central misconstrual of formal apparatus of (...) recursive operations such as the set-theoretic operation merge has led to a mathematisation of the object of inquiry, producing a strong analogy with discrete mathematics and especially arithmetic. The main product of this error has been the assumption that natural, like some formal, languages are discretely infinite. I will offer an alternative means of capturing the insights and observations related to this posit in terms of scientific modelling. My chief aim will be to draw from the larger philosophy of science literature in order to offer a position of grammars as models compatible with various foundational interpretations of linguistics while being informed by contemporary ideas on scientific modelling for the natural and social sciences. (shrink)

For the past two decades, it has widely been assumed by linguists that there is a single computational operation, Merge, which is unique to language, distinguishing it from other cognitive domains. The intention of this paper is to progress the discussion of language evolution in two ways: (i) survey what the ethological record reveals about the uniqueness of the human computational system, and (ii) explore how syntactic theories account for what ethology may determine to be human-specific. It is shown that (...) the operation Label, not Merge, constitutes the evolutionary novelty which distinguishes human language from non-human computational systems; a proposal lending weight to a Weak Continuity Hypothesis and leading to the formation of what is termed Computational Ethology. Some directions for future ethological research are suggested. (shrink)

The ability to process center‐embedded structures has been claimed to represent a core function of the language faculty. Recently, several studies have investigated the learning of center‐embedded dependencies in artificial grammar settings. Yet some of the results seem to question the learnability of these structures in artificial grammar tasks. Here, we tested under which exposure conditions learning of center‐embedded structures in an artificial grammar is possible. We used naturally spoken syllable sequences and varied the presence of prosodic cues. The results (...) suggest that mere distributional information does not suffice for successful learning. Prosodic cues marking the boundaries of the major relevant units, however, can lead to learning success. Thus, our data are consistent with the hypothesis that center‐embedded syntactic structures can be learned in artificial grammar tasks if language‐like acoustic cues are provided. (shrink)

There are remarkable behavioral, neural, and genetic similarities between the way songbirds learn to sing and human infants learn to speak. Furthermore, the brain regions involved in birdsong learning, perception, and production have been identified and characterized in detail. In particular, the caudal medial nidopallium (the avian analog of the mammalian auditory‐association cortex) has been found to contain the neural substrate of auditory memory, paving the way for analyses of the underlying molecular mechanisms. Recently, the zebra finch genome was sequenced, (...) and annotated cDNA databases representing over 15,000 unique brain‐expressed genes are available, enabling high‐throughput gene expression analyses. Here we review the involvement of immediate early genes (e.g. zenk and arc), their downstream targets (e.g. synapsins), and their regulatory signaling pathways (e.g. MAPK/ERK) in songbird memory. We propose that in‐depth investigations of zenk‐ and ERK‐dependent cascades will help to further unravel the molecular basis of auditory memory. (shrink)

This paper is an attempt at exploring the possibility of reconciling the two interpretations of biolinguistics which have been recently projected by Koster(Biolinguistics 3(1):61–92, 2009). The two interpretations—trivial and nontrivial—can be roughly construed as non-internalist and internalist conceptions of biolinguistics respectively. The internalist approach boils down to a conception of language where language as a mental grammar in the form of I-language grows and functions like a biological organ. On the other hand, under such a construal consistent with Koster’s (Biolinguistics (...) 3(1):61-92, 2009), the non-internalist version does not necessarily have to be externalist in nature; rather it is a matter of mutual reinforcement of biology and culture under the rubric of a co-evolutionary dynamics. Here it will be argued that the apparent dichotomy between these two conceptions of biolinguistics can perhaps be resolved if we have a richer synthesis that accounts for both internalism and non-internalism. (shrink)

I offer a novel interpretation of Aristotle's psychology and notion of rationality, which draws the line between animal and specifically human cognition. Aristotle distinguishes belief (doxa), a form of rational cognition, from imagining (phantasia), which is shared with non-rational animals. We are, he says, “immediately affected” by beliefs, but respond to imagining “as if we were looking at a picture.” Aristotle's argument has been misunderstood; my interpretation explains and motivates it. Rationality includes a filter that interrupts the pathways between cognition (...) and behavior. This prevents the subject from responding to certain representations. Stress and damage compromise the filter, making the subject respond indiscriminately, as non-rational animals do. Beliefs are representations that have made it past the filter, which is why they can “affect [us] immediately.” Aristotle's claims express ceteris paribus generalizations, subject to exceptions. No list of provisos could turn them into non-vacuous universal claims, but this does not rob them of their explanatory power. Aristotle's cognitive science resolves a tension we grapple with today: it accounts for the specialness of human action and thinking within a strictly naturalistic framework. The theory is striking in its insight and explanatory power, instructive in its methodological shortcomings. (shrink)

Standard biological and philosophical treatments assume that dramatic genotypic or phenotypic change constitutes instantaneous speciation, and that barring such saltation, speciation is gradual evolutionary change in individual properties. Both propositions appear to be incongruent with standard theoretical perspectives on species themselves, since these perspectives are (a) non-pheneticist, and (b) tend to disregard intermediate cases. After reviewing certain key elements of such perspectives, it is proposed that species-membership is mediated by membership in a population. Species-membership depends, therefore, not on intrinsic characteristics (...) of an organism, but on relationship of an organism to others. A new definition of speciation is proposed in the spirit of this proposal. This definition implies that dramatic change is neither necessary nor sufficient for speciation. It also implies, surprisingly, that an organism can change species during its lifetime. (shrink)