Molecular organisms

Protistology, and evolutionary protistology in particular, is experiencing a golden research era. It is an extended one that can be dated back to the 1970s, which is when the molecular rebirth of microbial phylogeny began in earnest. John Archibald, a professor of evolutionary microbiology at Dalhousie University (Nova Scotia, Canada), focuses on the beautiful story of endosymbiosis in his book, John Archibald, One Plus One Equals One: Symbiosis and the Origin of Complex Life (Oxford: Oxford University Press, 2014). However, this historical narrative could be treated as synecdochal of how the molecular revolution has changed evolutionary biology forever, and that is how Archibald has structured his book. I will address the encompassing theme of molecular methods in detail, but also pay careful attention to the endosymbiosis thread in its own right.     

Georges Teissier (1900–1972) and the Modern Synthesis in France

This Perspectives is devoted to the ideas of the French zoologist Georges Teissier about the mechanisms of evolution and the relations between micro- and macroevolution. Working in an almost universally neo-Lamarckian context in France, Teissier was one of the very few Darwinians there at the time of the evolutionary synthesis. The general atmosphere of French zoology during the 1920s and the 1930s will first be recalled, to understand the specific conditions in which Teissier became a zoologist. After a brief overview of his joint work with Philippe L’Héritier on the experimental genetics of Drosophila, this article describes the ways Teissier, during the 1950s, conceptualized the mechanisms that could allow for macroevolutionary transitions.IT is usually acknowledged that France did not significantly participate in the elaboration of 20th century evolutionary theory, often designated The Modern Synthesis. In their classical book on the history of the synthesis, Ernst Mayr and William B. Provine devoted a whole—nonetheless small—chapter to this specific issue (Mayr and Provine 1998, pp. 309–328). Mayr clearly stated that “France is the only major scientific nation that did not contribute significantly to the evolutionary synthesis” (Mayr 1998, p. 309). In the absence of a French architect of the synthesis, Mayr and Provine asked Ernest Boesiger, a Swiss population geneticist and a former student of Georges Teissier, to tell the story of what had happened in French biology at the time of the evolutionary synthesis. Boesiger, who died in 1975, wrote a paper in 1974 that provided the firm basis of the chapter. In very strong terms, he depicted French biology as “a kind of living fossil in the rejection of modern evolutionary theories” (Boesiger 1998, p. 309). He insisted on the fact that, even in 1974, most French biologists and philosophers were still reluctant to accept Darwinism. As regards the period of the 1930s, Boesiger was able to think of only two exceptions: Georges Teissier and Philippe L’Héritier. He then referred to their joint research in population genetics, which was based on the new technique of the population cages with the species Drosophila melanogaster, and listed their contributions to this new discipline.If Teissier and L’Héritier’s works on Drosophila are nowadays more widely recognized than in 1974, due in particular to the efforts of Jean Gayon and Michel Veuille (Gayon and Veuille 2001), this recognition could have as an unintended consequence the reduction of both Teissier and L’Héritier to being simply the inventors of a useful technique, namely the population cages (see especially how Mayr presented their work in his other classical book, Mayr 1982, p. 574), or as the founders of a French school of population geneticists (Gayon and Veuille 2001). The aim of this article is to reevaluate the way Georges Teissier (1900–1972) conceived Darwinian natural selection not only as an important mechanism for evolution at the population level but more fundamentally as a general key for the unification of biology, exactly as Julian Huxley or Ernst Mayr did during the same period (1930–1970). However, starting in the early 1950s, Teissier went on to conceive a very specific understanding of the evolutionary synthesis.In this article, I will first describe the general atmosphere of evolutionary issues in French biology at the time when Teissier started working as a zoologist, to understand against what he developed his joint research program with L’Héritier and afterward his general conceptions about evolution. During the 1930s and the 1940s, only a very few scientists in France could be seen as Darwinians. In addition to Teissier and L’Héritier, one may also consider Marcel Prenant, Boris Ephrussi, and the mathematician Gustave Malécot. Building on Jean Gayon and Michel Veuille’s work, I will then give a quick overview of L’Héritier and Teissier’s most important achievements in the field of population genetics. In the third part, I will discuss the discovery made by Teissier and L’Héritier of a case of cytoplasmic inheritance in Drosophila. This unexpected finding led them into the field of non-Mendelian heredity. I will then develop in detail the way Teissier finally went on to conceive the relation between microevolution and macroevolution, in light of the general context of French biology and of the development of the field of cytoplasmic inheritance.     

The Tragedy of a priori Selectionism: Dennett and Gould on Adaptationism

In his recent book on Darwinism, Daniel Dennett has offered up a species of a priori selectionism that he calls algorithmic. He used this view to challenge a number of positions advocated by Stephen J. Gould. I examine his algorithmic conception, review his unqualified enthusiasm for the a priori selectionist position, challenge Dennett's main metaphors (cranes vs. skyhooks and a design space), examine ways in which his position has lead him to misunderstand or misrepresent Gould (spandrels, exaptation, punctuated equilibrium, contingency and disparity), and discuss recent results in developmental biology that suggest that an a priori position does not fill the demands of an evolutionary biology. I conclude by insisting that evolutionary biology is many leveled, complicated, and is carried on an ever shifting and expanding empirical base that when disregarded results in caricature.     

Rupert Riedl and the re-synthesis of evolutionary and developmental biology: body plans and evolvability

This paper reviews the scientific career of Rupert Riedl and his contributions to evolutionary biology. Rupert Riedl, a native of Vienna, Austria, began his career as a marine biologist who made important contributions to the systematics and anatomy of major invertebrate groups, as well as to marine ecology. When he assumed a professorship at the University of North Carolina in 1968, the predominant thinking in evolutionary biology focused on population genetics, to the virtual exclusion of most of the rest of biology. In this atmosphere Riedl developed his "systems theory" of evolution, which emphasizes the role of functional and developmental integration in limiting and enabling adaptive evolution by natural selection. The main objective of this theory is to account for the observed patterns of morphological evolution, such as the conservation of body plans. In contrast to other "alternative" theories of evolution, Riedl never denied the importance of natural selection as the driving force of evolution, but thought it necessary to contextualize natural selection with the organismal boundary conditions of adaptation. In Riedl's view development is the most important factor besides natural selection in shaping the pattern and processes of morphological evolution.     

Okasha’s evolution and the levels of selection: toward a broader conception of theoretical biology

The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha’s book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that sees scientists and philosophers coming together to build a broadened concept of “theory” through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome.     

The life and times of Ferruccio Ritossa

Ferruccio Ritossa wrote these lines only a few months before he died, as a preface to a book he wanted to write and that, unfortunately, we will never be able to read. It was to be the story of his life, an amazing story indeed. With this article, we want to take a picture of Ferruccio’s life, a mosaic of events, facts, ideas, hopes, and memories linked in a way that they will not go away, even after “a stroll in our brain.”     

Samir Okasha: Evolution and the levels of selection

The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha’s book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that sees scientists and philosophers coming together to build a broadened concept of “theory” through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome.     

Szallasi Zoltan,Stelling Jörg,Periwal Vipul: System Modeling in Cellular Biology: From Concepts to Nuts and Bolts.

"System Modeling in Cellular Biology: From Concepts to Nuts and Bolts" by Szallasi, Stelling and Periwal introduces the relevant concepts, terminology, and techniques of this field of science. It emphasises the modelling and computational challenges of taking a multidisciplinary approach to biology. This book provides a comprehensive introduction to systems biology and will form a valuable resource for students, teachers and researchers from both experimental and theoretical disciplines.     

Haeckel's ABC of evolution and development

One of the central, unresolved controversies in biology concerns the distribution of primitive versus advanced characters at different stages of vertebrate development. This controversy has major implications for evolutionary developmental biology and phylogenetics. Ernst Haeckel addressed the issue with his Biogenetic Law, and his embryo drawings functioned as supporting data. We re-examine Haeckel's work and its significance for modern efforts to develop a rigorous comparative framework for developmental studies. Haeckel's comparative embryology was evolutionary but non-quantitative. It was based on developmental sequences, and treated heterochrony as a sequence change. It is not always clear whether he believed in recapitulation of single characters or entire stages. The Biogenetic Law is supported by several recent studies -- if applied to single characters only. Haeckel's important but overlooked alphabetical analogy of evolution and development is an advance on von Baer. Haeckel recognized the evolutionary diversity in early embryonic stages, in line with modern thinking. He did not necessarily advocate the strict form of recapitulation and terminal addition commonly attributed to him. Haeckel's much-criticized embryo drawings are important as phylogenetic hypotheses, teaching aids, and evidence for evolution. While some criticisms of the drawings are legitimate, others are more tendentious. In opposition to Haeckel and his embryo drawings, Wilhelm His made major advances towards developing a quantitative comparative embryology based on morphometrics. Unfortunately His's work in this area is largely forgotten. Despite his obvious flaws, Haeckel can be seen as the father of a sequence-based phylogenetic embryology.     

Homology and the hierarchy of biological systems

Homology is the similarity between organisms due to common ancestry. Introduced by Richard Owen in 1843 in a paper entitled "Lectures on comparative anatomy and physiology of the invertebrate animals", the concept of homology predates Darwin's "Origin of Species" and has been very influential throughout the history of evolutionary biology. Although homology is the central concept of all comparative biology and provides a logical basis for it, the definition of the term and the criteria of its application remain controversial. Here, I will discuss homology in the context of the hierarchy of biological organization. I will provide insights gained from an exemplary case study in evolutionary developmental biology that indicates the uncoupling of homology at different levels of biological organization. I argue that continuity and hierarchy are separate but equally important issues of homology.     

Howard A. Schneiderman--Planetary Patriot

SYNOPSIS. This symposium on arthropod development is dedicatedto the memory of Howard A. Schneiderman, who died on December5, 1990. Howard devoted much of his professional life to researchon arthropods and was the author of numerous publications onthe developmental biology of moths and flies. At Case-WesternReserve University and at the University of California-Irvinehe founded research institutes devoted to developmental biologyon arthropods as well as other organisms. Howard Schneidermanchampioned the use of insect growth regulators, which derivedfrom his research on the chemistry and physiology of juvenilehormone, as environmentally innocuous methods of controllinginsect pests of our food and fiber. In recent years he was aproponent of the use of molecular biology to alter the plantgenome so that insect-resistant crops might be grown and therebyreduce the use of insecticides. His global perspective was evidentin his understanding of how biotechnology could be applied toworld agriculture. Moreover, he quickly achieved prominencein promoting industry-university relations in his capacity asSenior Vice President for Research and Development at the MonsantoCompany. The cooperation among academic and industrial institutionsthat he fostered stands as a model for such relationships. HowardSchneiderman's influence on science and its applications, andon the universityindustry interface was profound and will befelt for many years to come.     

A Delicate Adjustment: Wallace and Bates on the Amazon and “The Problem of the Origin of Species”

For over a century it has been believed that Alfred Russel Wallace and Henry Walter Bates set out for the Amazon in 1848 with the aim of “solving the problem of the origin of species”. Yet this enticing story is based on only one sentence. Bates claimed in the preface to his 1863 book that Wallace stated this was the aim of their expedition in an 1847 letter. Bates gave a quotation from the letter. But Wallace himself never endorsed or repeated this story. Many writers have acknowledged that this letter still survives. Yet the wording is different from that quoted by Bates and the letter says nothing of an expedition. It is argued that the sentence given by Bates is not a genuine quotation from this or any other Wallace letter but was modified by Bates to promote his own reputation. More significantly, this leads to the conclusion that there was a very sudden and dramatic shift in the way species were thought of and discussed after Darwin’s Origin of species appeared. Something called “the problem of the origin of species” (and similar variants) never occurred before Darwin’s book but exploded in frequency immediately after it. A profound change in how species origins were discussed happened which no one seemed to notice.     

Phylogeny,fossils, and model systems in the study of evolutionary developmental biology

The emerging field of evolutionary developmental biology (evo-devo) continues to operate largely under a single paradigm. In this paradigm developmental regulatory genes and processes are compared among a collection of "model organisms" selected primarily on the basis of their historical utility in the study of development. This approach has proven to be extremely informative, revealing an unexpected deep evolutionary conservation among developmental genes and genetic systems. Despite its success, concern has been expressed regarding its limitations. We discuss the "model organism" paradigm in evo-devo research. Based on our interpretation of its limitations, we propose a separate but complementary approach that is centered on "model groups." These groups are selected on the basis of their taxonomic affinity and their relevance to questions of interest to evo-devo biologists. We further discuss the Tetraodontiformes (Teleostei, Pisces) as an example of a "model group" for the evo-devo study of vertebrate skeletal elements.     

Garland Allen,Thomas Hunt Morgan,and Development

Garland E. Allen’s 1978 biography of the Nobel Prize winning biologist Thomas Hunt Morgan provides an excellent study of the man and his science. Allen presents Morgan as an opportunistic scientist who follows where his observations take him, leading him to his foundational work in Drosophila genetics. The book was rightfully hailed as an important achievement and it introduced generations of readers to Morgan. Yet, in hindsight, Allen’s book largely misses an equally important part of Morgan’s work – his study of development and regeneration. It is worth returning to this part of Morgan, exploring what Morgan contributed and also why he has been seen by contemporaries and historians such as Allen as having set aside some of the most important developmental problems. A closer look shows how Morgan’s view of cells and development that was different from that of his most noted contemporaries led to interpretation of his important contributions in favor of genetics. This essay is part of a special issue, revisiting Garland Allen's views on the history of life sciences in the twentieth century.     

Making developmental biology relevant to undergraduates in an era of economic rationalism in Australia

This report describes the road map we followed at our university to accommodate three main factors: financial pressure within the university system; desire to enhance the learning experience of undergraduates; and motivation to increase the prominence of the discipline of developmental biology in our university. We engineered a novel, multi-year undergraduate developmental biology program which was "student-oriented," ensuring that students were continually exposed to the underlying principles and philosophy of this discipline throughout their undergraduate career. Among its key features are introductory lectures in core courses in the first year, which emphasize the relevance of developmental biology to tissue engineering, reproductive medicine, therapeutic approaches in medicine, agriculture and aquaculture. State-of-the-art animated computer graphics and images of high visual impact are also used. In addition, students are streamed into the developmental biology track in the second year, using courses like human embryology and courses shared with cell biology, which include practicals based on modern experimental approaches. Finally, fully dedicated third-year courses in developmental biology are undertaken in conjunction with stand-alone practical courses where students experiencefirst-hand work in a research laboratory. Our philosophy is a "cradle-to-grave" approach to the education of undergraduates so as to prepare highly motivated, enthusiastic and well-educated developmental biologists for entry into graduate programs and ultimately post-doctoral research.     

The new nativism: a commentary on Gary Marcus’s The birth of the mind

Gary Marcus (2004) has written a very interesting book about mental development from a nativist perspective. For the general readership at which the book is largely aimed, it will be interesting because of its many informative examples of the development of cognitive structures and because of its illuminating explanations of ways in which genes can contribute to these developmental processes. However, the book is also interesting from a theoretical point of view. Marcus tries to make nativism compatible with the central arguments that anti-nativists use to attack nativism and with many recent discoveries about genetic activity and brain development. In so doing, he reconfigures the nativist position to a considerable extent. Marcus’s theory is certainly more sophisticated than any version of nativism on the market. However, in our view Marcus ends up reconfiguring the nativist position out of existence. While many of the points that Marcus makes are both interesting and correct, we see no compelling reason to classify his considered position with traditional nativism rather than anti-nativism. More generally, we that think his book points to a general moral: the opposition between nativism and anti-nativism does not help us to understand psycho-developmental issues, and should therefore be abandoned.     

The generation of variation and the developmental basis for evolutionary novelty

Organisms exhibit an incredible diversity of form, a fact that makes the evolution of novelty seemingly self-evident. However, despite the "obvious" case for novelty, defining this concept in evolutionary terms is highly problematic, so much so that some have suggested discarding it altogether. Approaches to this problem tend to take either an adaptation- or development-based perspective, but we argue here that an exclusive focus on either of these misses the original intent of the novelty concept and undermines its practical utility. We propose instead that for a feature to be novel, it must have evolved both by a transition between adaptive peaks on the fitness landscape and that this transition must have overcome a previous developmental constraint. This definition focuses novelty on the explanation of apparently difficult or low-probability evolutionary transitions and highlights how the integration of developmental and functional considerations are necessary to evolutionary explanation. It further reinforces that novelty is a central concern not just of evolutionary developmental biology (i.e., "evo-devo") but of evolutionary biology more generally. We explore this definition of novelty in light of four examples that range from the obvious to subtle. J. Exp. Zool. (Mol. Dev. Evol.) 318B:501-517, 2012. ? 2012 Wiley Periodicals, Inc.     

Evolutionary convergences and parallelisms: &;their theoretical differences and the difficulty &;of discriminating them in a practical &;phylogenetic context

The importance of evolutionary parallelisms and their differences from evolutionary convergences have been historically underappreciated, as recently noticed in Gould's last book `The structure of evolutionary history'. In that book, Gould make an effort to distinguish and to reinterpret these concepts in the light of the new discoveries of the last decades on developmental biology and genetics, presenting the elegant metaphor of `Pharaonic bricks versus Corinthian columns'. In this paper I will briefly discuss these concepts, and will argue that, despite the advances that have been made to define them in theory, it is rather hard to differentiate them in a practical phylogenetic context. In order to do so, I will provide some few examples from my own empirical studies on the last years of one of the most morphologically and taxonomically diverse groups of Vertebrates, the catfishes.     

From the "Modern Synthesis" to cybernetics: Ivan Ivanovich Schmalhausen (1884-1963) and his research program for a synthesis of evolutionary and developmental biology

Ivan I. Schmalhausen was one of the central figures in the Russian development of the "Modern Synthesis" in evolutionary biology. He is widely cited internationally even today. Schmalhausen developed the main principles of his theory facing the danger of death in the totalitarian Soviet Union. His great services to evolutionary and theoretical biology are indisputable. However, the received view of Schmalhausen's contributions to evolutionary biology makes an unbiased reading of his texts difficult. Here we show that taking all of his works into consideration (including those only available in Russian) paints a much more dynamic and exciting picture of what he tried to achieve. Schmalhausen pioneered the integration of a developmental perspective into evolutionary thinking. A main tool for achieving this was his approach to living objects as complex multi-level self-regulating systems. Schmalhausen put enormous effort into bringing this idea into fruition during the final stages of his career by combining evolutionary theory with cybernetics. His results and ideas remain thought-provoking, and his texts are of more than just historical interest.