The mathematical theory of communication.

John Maynard Smith has defended against philosophical criticism the view that developmental biology is the study of the expression of information encoded in the genes by natural selection. However, like other naturalistic concepts of information, this ‘teleosemantic’ information applies to many non-genetic factors in development. Maynard Smith also fails to show that developmental biology is concerned with teleosemantic information. Some other ways to support Maynard Smith’s conclusion are considered. It is argued that on any definition of information the view that (...) development is the expression of genetic information is misleading. Some reasons for the popularity of that view are suggested. (shrink)

There is no consensus yet on the definition of semantic information. This paper contributes to the current debate by criticising and revising the Standard Definition of semantic Information (SDI) as meaningful data, in favour of the Dretske‐Grice approach: meaningful and well‐formed data constitute semantic information only if they also qualify as contingently truthful. After a brief introduction, SDI is criticised for providing necessary but insufficient conditions for the definition of semantic information. SDI is incorrect because truth‐values do not supervene on (...) semantic information, and misinformation (that is, false semantic information) is not a type of semantic information, but pseudo‐information, that is not semantic information at all. This is shown by arguing that none of the reasons for interpreting misinformation as a type of semantic information is convincing, whilst there are compelling reasons to treat it as pseudo‐information. As a consequence, SDI is revised to include a necessary truth‐condition. The last section summarises the main results of the paper and indicates some interesting areas of application of the revised definition. (shrink)

With the publication of this inaugural issue of the internationally peer-reviewed journal Biosemiotics, our still-developing young interdiscipline marks yet another milestone in its journey towards adulthood. For this occasion, the editors of Biosemiotics have asked me to provide for those readers who may be newcomers to our field a very brief overview of the history of biosemiotics, contextualizing it within and against the larger currents of philosophical and scientific thinking from which it has emerged. To explain the origins of this (...) most twenty-first century endeavour effectively, however, will require tracing—at least to the level of a thumbnail sketch—how the ‘sign’ concept appeared, was lost, and now must be painstakingly rediscovered and refined in science. To relate this long history, this article will appear in Biosemiotics in three instalments, examining, respectively: (1) The History of the Sign Concept in Pre-Modernist Science, (2) The History of the Sign Concept in Modernist Science, and (3) The Biosemiotic Attempt to Develop a More Useful Sign Concept for Contemporary Science. In this instalment, we begin our introductory ‘stroll through the woods of sciences and signs’ by following the development of the sign concept within the context of scientific inquiry, in necessarily broad outline, from the beginnings of such inquiry in sixth century BCE, through its long development in the Middle Ages, and up unto the onset of modernity. For only within this larger historical context can our contemporary attempt to develop a naturalistic understanding of sign relations be understood. (shrink)

Biologists rely heavily on the language of information, coding, and transmission that is commonplace in the field of information theory developed by Claude Shannon, but there is open debate about whether such language is anything more than facile metaphor. Philosophers of biology have argued that when biologists talk about information in genes and in evolution, they are not talking about the sort of information that Shannon’s theory addresses. First, philosophers have suggested that Shannon’s theory is only useful for developing a (...) shallow notion of correlation, the so-called causal sense of information. Second, they typically argue that in genetics and evolutionary biology, information language is used in a semantic sense, whereas semantics are deliberately omitted from Shannon’s theory. Neither critique is well-founded. Here we propose an alternative to the causal and semantic senses of information: a transmission sense of information, in which an object X conveys information if the function of X is to reduce, by virtue of its sequence properties, uncertainty on the part of an agent who observes X. The transmission sense not only captures much of what biologists intend when they talk about information in genes, but also brings Shannon’s theory back to the fore. By taking the viewpoint of a communications engineer and focusing on the decision problem of how information is to be packaged for transport, this approach resolves several problems that have plagued the information concept in biology, and highlights a number of important features of the way that information is encoded, stored, and transmitted as genetic sequence. (shrink)

Communication is an important feature of the living world that mainstream biology fails to adequately deal with. Applying two main disciplines can be contemplated to fill in this gap: semiotics and information theory. Semiotics is a philosophical discipline mainly concerned with meaning; applying it to life already originated in biosemiotics. Information theory is a mathematical discipline coming from engineering which has literal communication as purpose. Biosemiotics and information theory are thus concerned with distinct and complementary possible meanings of the word (...) ‘communication’. Since literal communication needs to be secured so as to enable semantics being communicated, information theory is a necessary prerequisite to biosemiotics. Moreover, heredity is a purely literal communication process of capital importance fully relevant to literal communication, hence to information theory. A short introduction to discrete information theory is proposed, which is centred on the concept of redundancy and its use in order to make sequences resilient to errors. Information theory has been an extremely active and fruitful domain of researches and the motor of the tremendous progress of communication engineering in the last decades. Its possible connections with semantics and linguistics are briefly considered. Its applications to biology are suggested especially as regards error-correcting codes which are mandatory for securing the conservation of genomes. Biology needs information theory so biologists and communication engineers should closely collaborate. (shrink)

Since the beginning of the XX-th century, it became increasingly evident that information, besides matter and energy, is a major actor in the life processes. Moreover, communication of information has been recognized as differentiating living things from inanimate ones, hence as specific to the life processes. Therefore the sciences of matter and energy, chemistry and physics, do not suffice to deal with life processes. Biology should also rely on sciences of information. A majority of biologists, however, did not change their (...) mind and continued to describe life in terms of chemistry and physics. They merely borrowed some vocabulary from the information sciences. The first science of information available to biological applications, semiotics, appeared at the end of the XIX-th century. It is a qualitative and descriptive science which stemmed from efforts of linguists and philosophers to understand the human language and is thus mainly concerned with semantics. Applying semiotics to biology resulted in today’s Biosemiotics. Independently, an explosive expansion of communication engineering began in the second half of the XX-th century. Besides tremendous progresses in hardware technology, it was made possible by the onset of a science of literal communication: Information Theory (Shannon, Bell Syst Tech J 27:379–457, 623–656, 1948). Literal communication consists of faithfully transporting a message from a place to another, or from an instant to another. Because the meaning of a message does not matter for its transportation, information theory ignores semantics. This restriction enables defining information as a measurable quantity on which a mathematical theory of communication is founded. Although lacking implementation means at its beginning, information theory became later very successful for designing communication means. Modern ones, like mobile phones, can be thought of as experimentally proving the relevance and accuracy of information theory since their design and operation heavily rely on it. Information theory is plainly relevant to biological functions which involve literal communication, especially heredity. This paper is intended to compare the two approaches. It shows that, besides obvious differences, they have some points in common: for instance, the quantitative measurement of information obeys Peirce’s triadic paradigm. They also can mutually enlighten each other. Using information theory, which is closer to the basic communication mechanisms, may appear as a preliminary step prior to more elaborated investigations. Criticizing genetics from outside, information theory furthermore reveals that the ability of the template-replication paradigm to faithfully conserve genomes is but a prejudice. Heredity actually demands error-correcting means which impose severe constraints to the living world and must be recognized as biological facts. (shrink)

The discovery of the genetic code has shown that the origin of life has also been the origin of semiosis, and the discovery of many other organic codes has indicated that organic semiosis has been the sole form of semiosis present on Earth in the first three thousand million years of evolution. With the origin of animals and the evolution of the brain, however, a new type of semiosis came into existence, a semiosis that is based on interpretation and is (...) commonly referred to as interpretive, or Peircean semiosis. This suggests that there are two distinct types of semiosis in Nature, one based on coding and one based on interpretation, and all the experimental evidence that we have does support this conclusion. Both in principle and in practice, therefore, there is no conflict between organic semiosis and Peircean semiosis, and yet they have been the object of a fierce controversy because it has been claimed that semiosis is always based on interpretation, even at the cellular level. Such a claim has recently been reproposed in a number of papers and it has become necessary therefore to reexamine it in the light of the proposed arguments. (shrink)

We argue that living systems process information such that functionality emerges in them on a continuous basis. We then provide a framework that can explain and model the normativity of biological functionality. In addition we offer an explanation of the anticipatory nature of functionality within our overall approach. We adopt a Peircean approach to Biosemiotics, and a dynamical approach to Digital-Analog relations and to the interplay between different levels of functionality in autonomous systems, taking an integrative approach. We then apply (...) the underlying biosemiotic logic to a particular biological system, giving a model of the B-Cell Receptor signaling system, in order to demonstrate how biosemiotic concepts can be used to build an account of biological information and functionality. Next we show how this framework can be used to explain and model more complex aspects of biological normativity, for example, how cross-talk between different signaling pathways can be avoided. Overall, we describe an integrated theoretical framework for the emergence of normative functions and, consequently, for the way information is transduced across several interconnected organizational levels in an autonomous system, and we demonstrate how this can be applied in real biological phenomena. Our aim is to open the way towards realistic tools for the modeling of information and normativity in autonomous biological agents. (shrink)

Exactly how do the sign/symbol/token systems of endo- and exo-biosemiosis differ from those of cognitive semiosis? Do the biological messages that integrate metabolism have conceptual meaning? Semantic information has two subsets: Descriptive and Prescriptive. Prescriptive information instructs or directly produces nontrivial function. In cognitive semiosis, prescriptive information requires anticipation and “choice with intent” at bona fide decision nodes. Prescriptive information either tells us what choices to make, or it is a recordation of wise choices already made. Symbol systems allow recordation (...) of deliberate choices and the transmission of linear digital prescriptive information. Formal symbol selection can be instantiated into physicality using physical symbol vehicles (tokens). Material symbol systems (MSS) formally assign representational meaning to physical objects. Even verbal semiosis instantiates meaning into physical sound waves using an MSS. Formal function can also be incorporated into physicality through the use of dynamically-inert (dynamically-incoherent or -decoupled) configurable switch-settings in conceptual circuits. This paper examines the degree to which biosemiosis conforms to the essential formal criteria of prescriptive semiosis and cybernetic management. (shrink)

A historical and critical analysis of the concept of the gene that attempts to provide new perspectives and metaphors for the transformation of biology and its philosophy.

This article explores the connection between objective chance and the randomness of a sequence of outcomes. Discussion is focussed around the claim that something happens by chance iff it is random. This claim is subject to many objections. Attempts to save it by providing alternative theories of chance and randomness, involving indeterminism, unpredictability, and reductionism about chance, are canvassed. The article is largely expository, with particular attention being paid to the details of algorithmic randomness, a topic relatively unfamiliar to philosophers.

The concept of information has acquired a strikingly prominent role in contemporary biology. This trend is especially marked within genetics, but it has also become important in other areas, such as evolutionary theory and developmental biology, particularly where these fields border on genetics. The most distinctive biological role for informational concepts, and the one that has generated the most discussion, is in the description of the relations between genes and the various structures and processes that genes play a role in (...) causing. For many biologists, the causal role of genes should be understood in terms of their carrying information about their various products. That information might require the cooperation of various environmental factors before it can be "expressed," but the same can be said of other kinds of message. An initial response might be to think that this mode of description is entirely anchored in a set of well-established facts about the role of DNA and RNA within protein synthesis, summarized in the familiar chart representing the "genetic code," mapping DNA base triplets to amino acids. However, informational enthusiasm in biology predates even a rudimentary understanding of these mechanisms (Schrodinger 1944). And more importantly, current applications of informational concepts extend far beyond anything that can receive an obvious justification in terms of the familiar facts about the specification of protein molecules by DNA. This includes: 1 (i) The description of whole-organism phenotypic traits (including complex behavioral traits) as specified or coded for by information contained in the genes, (ii) The treatment of many causal processes within cells, and perhaps of the wholeorganism developmental sequence, in terms of the execution of a program stored in the genes, (iii) The idea that genes themselves, for the purpose of evolutionary theorizing, should be seen as, in some sense, "made" of information.. (shrink)