First, we will address the unnecessary link between symbio-studies and Gaia, asking for the historical and epistemological reasons why they become associated. In particular, we contend that the association is mediated by the common interest in large-scale physico-chemical and biochemical patterns, rather than by an emphasis on harmony, equilibrium, and cooperation (Visvader 1992). Second, we will ask what Gaia is in a metatheoretical sense: is it a scientific hypothesis, a theory, a metaphor, an inspired invention, or a resurgence of antiscientific (...) attitude? After examining some alternatives that show the importance of metatheorizing, we will define Gaia a ‘scientific narrative’, this being a technical term in a sketchy metatheory. Let us just say, for now, that by narrative we don’t mean fairytale or artistic fiction, but rather a way of telling the history of our planet. We are not going to answer the question whether or not we should ban Gaia from any scientific discourse, nor the question how symbio-students should deal with the traditional association of their field with Gaia. But we hope to frame the dilemma in which symbio-students and the scientific community at large are held in a better way than simply insisting on classic demarcations between science and non-science. (shrink)

The appeal to mechanisms in scientific explanation is commonplace in contemporary philosophy of science. In short, mechanists argue that an explanation of a phenomenon consists of citing the mechanism that brings the phenomenon about. In this paper, we present an argument that challenges the universality of mechanistic explanation: in explanations of the contemporary features of the eukaryotic cell, biologists appeal to its symbiogenetic origin and therefore the notion of symbiogenesis plays the main explanatory role. We defend the notion that (...) symbiogenesis is non-mechanistic in nature and that any attempt to explain some of the contemporary features of the eukaryotic cell mechanistically turns out to be at least insufficient and sometimes fails to address the question that is asked. Finally, we suggest that symbiogenesis is better understood as a pragmatic scientific law and present an alternative non-mechanistic model of scientific explanation. In the model we present, the use of scientific laws is supposed to be a minimal requirement of all scientific explanations, since the purpose of a scientific explanation is to make phenomena expectable. Therefore, this model would help to understand biologists’ appeal to the notion of symbiosis and thus is shown to be better, for the case under examination, than the mechanistic alternative. (shrink)

Variation, adaptation, heredity and fitness, constraints and affordances, speciation, and extinction form the building blocks of the (Neo-)Darwinian research program, and several of these have been called “Darwinian principles.” Here, we suggest that caution should be taken in calling these principles Darwinian because of the important role played by reticulate evolutionary mechanisms and processes in also bringing about these phenomena. Reticulate mechanisms and processes include symbiosis, symbiogenesis, lateral gene transfer, infective heredity mediated by genetic and organismal mobility, and hybridization. (...) Because the “Darwinian principles” are brought about by both vertical and reticulate evolutionary mechanisms and processes, they should be understood as foundational for a more pluralistic theory of evolution, one that surpasses the classic scope of the Modern and the Neo-Darwinian Synthesis. Reticulate evolution moreover demonstrates that what conventional (Neo-)Darwinian theories treat as intra-species features of evolution frequently involve reticulate interactions between organisms from very different taxonomic categories. Variation, adaptation, heredity and fitness, constraints and affordances, speciation, and extinction therefore cannot be understood as “traits” or “properties” of genes, organisms, species, or ecosystems because the phenomena are irreducible to specific units and levels of an evolutionary hierarchy. Instead, these general principles of evolution need to be understood as common goods that come about through interactions between different units and levels of evolutionary hierarchies, and they are exherent rather than inherent properties of individuals. (shrink)

This paper investigates how reticulate evolution contributes to a better understanding of human sociocultural evolution in general, and community formation in particular. Reticulate evolution is evolution as it occurs by means of symbiosis, symbiogenesis, lateral gene transfer, infective heredity, and hybridization. From these mechanisms and processes, we mainly zoom in on symbiosis and we investigate how it underlies the rise of (1) human, plant, animal, and machine interactions typical of agriculture, animal husbandry, farming, and industrialization; (2) diet-microbiome relationships; and (...) (3) host-virome and other pathogen interactions that underlie human health and disease. We demonstrate that reticulate evolution necessitates an understanding of behavioral and cultural evolution at a community level, where reticulate causal processes underlie the rise of synergistic organizational traits. (shrink)

A theoretical framework is provided to explore teleonomy as a problem of self-causation, distinct from upward, downward and reticulate causation. Causality theories in biology are often formulated within hierarchy theories, where causation is conceptualized as running up or down the rungs of a ladder-like hierarchy or, more recently, as moving between multiple hierarchies. Research on the genealogy of cosmologies demonstrates that in addition to hierarchy theories, causality theories also depend upon ideas of time. This paper explores the roots and impact (...) of both time and hierarchy thinking on causal reasoning in the evolutionary sciences. Within evolutionary biology, the Neodarwinian synthesis adheres to a linear notion of time associated with linear hierarchies that portray upward causation. Eco-evo-devo schools recognize the importance of downward causation and consequently receive resistance from the standard view because downward causation is sometimes understood as backward causation, considered impossible by adherents of a linear time model. In contrast, downward causation works with a spatial or presential time notion. Hybridization, lateral gene transfer, infective heredity, symbiosis and symbiogenesis require recognition of reticulate causation occurring in both space and time, or spacetime, between distinct and interacting ontological hierarchies. Teleonomy is distinct from these types of causation because it invokes the problem of self-causation. By asking how the focal level in a hierarchy can persist through time, self-causation raises philosophical concerns on the nature of duration, identity and individuality. (shrink)

This chapter introduces the main research schools and paradigms along which the field of evolutionary biology has been developing. Evolutionary thinking was originally founded upon the Neo-Darwinian paradigm that combines the teachings of traditional Darwinism with those of the Modern Synthesis. The Neo-Darwinian paradigm has since further diversified into the Micro-, Meso-, and Macroevolutionary schools, and it has also started to integrate the school of Ecology. Together, these schools establish the paradigm called Ecological Evolutionary Developmental Biology (Eco-Evo-Devo). A final school (...) studies Reticulate Evolution as it occurs by means of symbiosis, symbiogenesis, lateral gene transfer, infective heredity, and hybridization. This chapter reviews the major tenets and points of differentiation that exist between these distinct evolution schools. The chapter ends by looking into how evolution can be defined and how distinct units, levels, and mechanisms underlie theorizing on evolutionary hierarchies and evolutionary causation. The following chapter examines how the different evolution schools are implemented into the symbolic sciences. (shrink)

Serial Endosymbiosis Theory, or SET, was conceived and developed by Lynn Margulis, to explain the greatest discontinuity in the history of life, the origin of eukaryotic cells. Some predictions of SET, namely the origin of mitochondria and chloroplasts, withstood the test of the most recent evidence from a variety of disciplines including phylogenetics, biochemistry, and cell biology. Even though some other predictions fared less well, SET remains a seminal theory in biology. In this paper, I focus on two aspects of (...) SET. First, using the concept of "universal symbiogenesis”, developed by Freeman Dyson to search for commonalities in astronomy and biology, I propose that SET can be extended beyond eukaryogenesis. The extension refers to the possibility that even prokaryotic organisms, themselves subject to the process of symbiogenesis in SET, could have emerged symbiotically. Second, I contrast a recent “viral eukaryogenesis” hypothesis, according to which the nucleus evolved from a complex DNA virus, with a view closer to SET, according to which the nucleus evolved through the interplay of the archaeal host, the eubacterial symbiont, and a non-LTR transposon, or telomerase. Viruses joined in later, through the process of viral endogenization, to shape eukaryotic chromosomes in the process of karyotype evolution. These two proposals based on SET are a testament to its longevity as a scientific theory. (shrink)

The year 2009 has been a year of numerous commemorations of both scientific and non-scientific achievements that contributed to the advancement of human kind. Protestants celebrated the 500th anniversary of the birth of Calvin; literary critics celebrated the 200th anniversary of the poet Edgar Allan Poe; and the musical genius Felix Mendelssohn-Bartholdy was also born 200 years ago. 2009 further marked the bicentennial of the birth of Louis Braille, the inventor of Braille; and Abraham Lincoln, the 16th president of the (...) United States, who founded the National Academy of Sciences. Pierre Curie, famous for his work on radioactivity that he conducted together with his wife Marie Curie, was born 150 ago; as was John Dewey, a philosopher and psychologist who is recognized as one of the founding fathers of both pragmatism as well as functional psychology. UNESCO and the International Astronomical Union dubbed 2009 the International Year of Astronomy. By doing so, astronomers celebrated the 400th anniversary of Galileo Galilei’s telescopic observations as well as the publication of Johannes Kepler’s Astronomia nova wherein he formulated the first two laws of planetary motion. 2009 also marked the last of a 3-year-long celebration of Planet Earth, another UNESCO-governed initiative. However, for evolutionary biologists and philosophers of science, 2009 will be largely remembered for its worldwide commemorations of the 200th anniversary of the birth of Charles Darwin, and the 150th anniversary of the publication of his magnum opus On the origin of species by means of natural selection. Footnote1 In order to pay tribute to Darwin’s major contribution to the advancement of evolutionary science, the International Union of Biological Sciences and the International Union of History and Philosophy of Science have called the year 2009 the Darwin Year. Given that so many scientific discoveries were commemorated, COPUS, the Coalition on the Public Understanding on Science, called out 2009 as the Year of Science, in the hope to pay equal tribute to both the field of biology as well as astronomy. 2009 was indeed a year of biology. Somewhat overshadowed by the big Darwin celebrations, smaller-scaled events were held to commemorate the 200th anniversary of the publication of Lamarck’s Philosophie Zoologique; and the 150th anniversary of the death of Alexander von Humboldt, the father of biogeography. In 1910, Constantin Mereschkowsky wrote his article on symbiogenesis entitled ‘The Theory of Two Plasmas as the Basis of Symbiogenesis, a New Study for the Origins of Organisms’. The article was published in the German Biologisches Zentralblatt, the journal that would later evolve into the current Theory in Biosciences. Somewhat forgotten, but equally important for the field of symbiogenesis, was the 200th anniversary of the birth of Pierre-Joseph Van Beneden, a Belgian paleontologist and zoologist famous for distinguishing parasitism from commensalism. Finally, Henry Bergson, known for inventing the currently rejected notion of élan vital, was born 150 years ago. In order to memorialize the important role these biologists played in the advancement of our understanding of the evolutionary process, a 2-day international conference was organized entitled: Evolution today and tomorrow, Darwin evaluated by contemporary evolutionary and philosophical theories. The conference was organized by The Centre for Philosophy of Science of the University of Lisbon (Portugal), in collaboration with the Centre for Environmental Biology of the same university, and the Lisbon Centre for Applied Psychology. The articles presented here are a spin-off of this conference. The current volumes contain the peer-reviewed articles of a selection of the plenary and invited speakers, as well as those of scholars who were additionally invited to contribute to the volumes. (shrink)