Towards an Evolutionary Biosemiotics: Semiotic Selection and Semiotic Co-option

In biosemiotics, living beings are not conceived of as the passive result of anonymous selection pressures acted upon through the course of evolution. Rather, organisms are considered active participants that influence, shape and re-shape other organisms, the surrounding environment, and eventually also their own constitutional and functional integrity. The traditional Darwinian division between natural and sexual selection seems insufficient to encompass the richness of these processes, particularly in light of recent knowledge on communicational processes in the realm of life. Here, we introduce the concepts of semiotic selection and semiotic co-option which in part represent a reinterpretation of classical biological terms and, at the same time, keep explanations sensitive to semiosic processes taking place in living nature. We introduce the term ‘semiotic selection’ to emphasize the fact that actions of different semiotic subjects (selectors) will produce qualitatively different selection pressures. Thereafter, ‘semiotic co-option’ explains how semiotic selection may shape appearance in animals through remodelling existing forms and relations. Considering the event of co-option followed by the process of semiotic selection enables us to describe the evolution of semantic organs.     

Darwin was right: inbreeding depression on male fertility in the Darwin family

Charles Darwin, who was married to his first cousin Emma Wedgwood, was the first experimentalist to demonstrate the adverse effects of inbreeding. He documented the deleterious consequences of self‐fertilization on progeny in numerous plant species, and this research led him to suspect that the health problems of his 10 children, who were very often ill, might have been a consequence of his marriage to his first cousin. Because Darwin's concerns regarding the consequences of cousin marriage on his children even nowadays are considered controversial, we analyzed the potential effects of inbreeding on fertility in 30 marriages of the Darwin–Wedgwood dynasty, including the marriages of Darwin's children, which correspond to the offspring of four cousin marriages and three marriages between unrelated individuals. Analysis of the number of children per woman through zero‐inflated regression models showed a significantly adverse effect of the husband inbreeding coefficient on family size. Furthermore, a statistically significant adverse effect of the husband inbreeding coefficient on reproductive period duration was also detected. To our knowledge, this is the first time that inbreeding depression on male fertility has been detected in humans. Because Darwin's sons had fewer children in comparison to non‐inbred men of the dynasty, our findings give empirical support to Darwin's concerns on the consequences of consanguineous marriage in his own progeny. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 474–483.     

Spatiotemporal Computations of an Excitable and Plastic Brain: Neuronal Plasticity Leads to Noise-Robust and Noise-Constructive Computations

It is a long-established fact that neuronal plasticity occupies the central role in generating neural function and computation. Nevertheless, no unifying account exists of how neurons in a recurrent cortical network learn to compute on temporally and spatially extended stimuli. However, these stimuli constitute the norm, rather than the exception, of the brain''s input. Here, we introduce a geometric theory of learning spatiotemporal computations through neuronal plasticity. To that end, we rigorously formulate the problem of neural representations as a relation in space between stimulus-induced neural activity and the asymptotic dynamics of excitable cortical networks. Backed up by computer simulations and numerical analysis, we show that two canonical and widely spread forms of neuronal plasticity, that is, spike-timing-dependent synaptic plasticity and intrinsic plasticity, are both necessary for creating neural representations, such that these computations become realizable. Interestingly, the effects of these forms of plasticity on the emerging neural code relate to properties necessary for both combating and utilizing noise. The neural dynamics also exhibits features of the most likely stimulus in the network''s spontaneous activity. These properties of the spatiotemporal neural code resulting from plasticity, having their grounding in nature, further consolidate the biological relevance of our findings.     

Darwin and Dostoyevsky: twins

The Russian poet Fyodor Dostoyevsky published an insightful treatise on human nature in his novel ‘The Brothers Karamazov'' in 1880. His account of humanity may offer as much insight into human nature for scientists as Darwin''s The Descent of Man.Late in the nineteenth century, Charles Darwin (1809–1882) and Fyodor Dostoyevsky (1821–1881) published accounts of their investigation of humankind. Darwin did so in 1871 in his book The Descent of Man, Dostoyevsky in 1880 in the parable of The Grand Inquisitor in his book The Brothers Karamazov. Last year we celebrated Darwin''s anniversary; for biologists, 2010—the 130th anniversary of Dostoyevsky''s book—might have been the year of Dostoyevsky.Dostoyevsky was familiar with Darwin''s doctrine and he was willing to admit “man''s descent from the ape”. An orthodox Christian, he put this sentiment in religious terms: “It does not really matter what man''s origins are, the Bible does not explain how God moulded him out of clay or carved him out of stone. Yet, he saw a difference between humans and animals: humans have a soul.The philosopher Nikolay Berdyayev noticed: “[Dostoyevsky] concealed nothing, and that''s why he could make astonishing discoveries. In the fate of his heroes he relates his own destiny, in their doubts he reveals his vacillations, in their ambiguity his self-splitting, in their criminal experience the secret crimes of his spirit.”The Grand Inquisitor can be read as Dostoyevsky''s treatise on human nature. In the tale, Jesus Christ revisits Earth during the period of the Inquisition and is arrested by the Church and sentenced to death. The Grand Inquisitor comes to visit Jesus in his prison cell to argue with him about their conceptions of human nature. He explains that humankind needs to be ruled to be happy and that the true freedom Jesus offered doomed humanity to suffering and unhappiness. Dostoyevsky''s superposition of these two points of view on humankind reminds us of the principle of complementarity, by which the physicist Niels Bohr attempted to account for the particle-wave duality of quantum physics.Dostoyevsky conceives of humans as complex, contradictory and inconsistent creatures. Humans perceive personal liberty as a burden and are willing to barter for it, as the Grand Inquisitor explained to Christ, for “miracle, mystery, and authority”. In addition, “the mystery of human being does not only rest in the desire to live, but in the problem: for what should one live at all?” We might say that these faculties make Homo sapiens a religious species. Not in the sense of believing in gods or a god, but in the sense of the Latin word religare, which means to bind, connect or enfold. Humans are mythophilic animals, driven by a need to find a complete explanation for events in terms of intentions and purposes.Research into the neurological bases of imagination, transcendence, metaphorability, art and religion, as well as moral behaviour and judgement (Trimble, 2007) is consistent with Dostoyevsky''s views. It has identified areas of the brain that have been labelled as the ‘god module'' or ‘god spot'' (Alper, 2001). These areas represent a new stratum of evolutionary complexity, an emergence specific to the human species. Their mental translations might be tentatively designated as the Darwinian soul, anchored in the material substrate and neither immortal nor cosmic. As consciousness and volition have become legitimate subjects of neuroscience (Baars, 2003), the Darwinian soul, and with it spirituality, seems to be ripe for scientific inquiry: the quest for meaning, creation and perception of metaphors, the experience of the trinity of Truth, Good and Beauty, the capacity for complex feelings that Immanuel Kant called sublimity, the thrill of humour and play, the power of empathy and the follies of boundless love or hate. Secularization does not erase the superstructure of spirituality: it is reflected, however queer it might seem, in the hypertrophy of the entertainment industry and also, more gloomily, in spiritual conflicts on a global scale.Dostoyevsky''s views on the human soul might be closer to those of Alfred Russel Wallace, who believed that an unknown force directed evolution towards an advanced organization. We can identify this ‘force'' as the second law of thermodynamics (Sharma & Annila, 2007). By moving evolving systems ever farther away from equilibrium, the second law eventually became the Creator of the ‘Neuronal God''.Christ, in the parable of the Grand Inquisitor, might be conceived of as a symbol of the truth outside the human world. Christ was listening to the assertions and questions of his interlocutor, but did not say a single word. His silence is essential to the parable.Similarly, the cosmos, to which humanity has been addressing its questions and predications, remains silent. By science, we increase knowledge only by tiny increments. The ‘god modules'' of our brains, unsatisfied and impatient, have hastily provided the full truth, deposited in the Holy Scripture. There are at least three books claiming to contain the revealed and hence unquestionable truth: the Judaic Torah, Christian Bible and Muslim Qur''an. A dogma of genocentrism in biology might offer an additional Scripture: the sequence of DNA in the genomes.Dostoyevsky''s legacy may suggest an amendment to the UN Charter. We, united humankind, solemnly declare: No truth has ever been revealed to us; we respect and tolerate each other in our independent searching and erring.     

Signs of the Self: An Exploration in Semiotic Anthropology

Peirce's general theory of signs, or semiotic, as he called it, yields a theory of the self that sees it both as the object and the subject of semiotic systems. From this viewpoint, the locus, unity, and continuity of the self will be found in the systems of signs that constitute the dialogues between utterers and interpreters of the signs. Personal identity, in this theory, is also a social and cultural identity and is not confined to the individual organism. Peirce's anti-Cartesianism, which denies intuitive and introspective knowledge of the self, derived that knowledge from the fallible inferences we all make from the observations of external facts, including the signs of the self. This laid the foundation for a semiotic psychology as well as for a semiotic anthropology. [self, semiotic anthropology, personal identity, C. S. Peirce]     

Mystery of mysteries: Darwin and the species problem

Darwin offered an intriguing answer to the species problem. He doubted the existence of the species category as a real category in nature, but he did not doubt the existence of those taxa called “species”. And despite his scepticism of the species category, Darwin continued using the word “species”. Many have said that Darwin did not understand the nature of species. Yet his answer to the species problem is both theoretically sound and practical. On the theoretical side, Darwin’s answer is confirmed by contemporary biology, and it offers a more satisfactory answer to the species problem than recent attempts to save the species category. On the practical side, Darwin’s answer frees us from the search for the correct theoretical definition of “species”. But at the same time it does not require that we banish the word “species” from biology as some recent sceptics of the species category advocate. © The Willi Hennig Society 2010.