Darwin as a student of behavior

In The Expression of the Emotions, Charles Darwin documents evolutionary continuity between animals and humans, emphasizing the universality of expressions in man. Most of the book addresses human behavior, and its influence on the study of animal behavior has been weak. The issue of natural selection is remarkably absent from this book, which relies on the inheritance of acquired characters rather than on a genuine Darwinian logic. Yet Konrad Lorenz considered Darwin to be a forerunner of behavioral biology. The reason was to be found in The Descent of Man and chapter VIII of The Origin of Species, where Darwin provides an explanation of behavior through selection, stating that the same mechanisms explaining morphological changes also account for gradual improvements in instincts. He assessed the accuracy of his evolutionary theory by directly studying animal behavior, hence laying the foundations of behavioral research for the next century.     

Why was Darwin’s view of species rejected by twentieth century biologists?

Historians and philosophers of science agree that Darwin had an understanding of species which led to a workable theory of their origins. To Darwin species did not differ essentially from ‘varieties’ within species, but were distinguishable in that they had developed gaps in formerly continuous morphological variation. Similar ideas can be defended today after updating them with modern population genetics. Why then, in the 1930s and 1940s, did Dobzhansky, Mayr and others argue that Darwin failed to understand species and speciation? Mayr and Dobzhansky argued that reproductively isolated species were more distinct and ‘real’ than Darwin had proposed. Believing species to be inherently cohesive, Mayr inferred that speciation normally required geographic isolation, an argument that he believed, incorrectly, Darwin had failed to appreciate. Also, before the sociobiology revolution of the 1960s and 1970s, biologists often argued that traits beneficial to whole populations would spread. Reproductive isolation was thus seen as an adaptive trait to prevent disintegration of species. Finally, molecular genetic markers did not exist, and so a presumed biological function of species, reproductive isolation, seemed to delimit cryptic species better than character-based criteria like Darwin’s. Today, abundant genetic markers are available and widely used to delimit species, for example using assignment tests: genetics has replaced a Darwinian reliance on morphology for detecting gaps between species. In the 150th anniversary of The Origin of Species, we appear to be returning to more Darwinian views on species, and to a fuller appreciation of what Darwin meant.     

Professionalization as a governance strategy for synthetic biology

This article considers professionalization as a governance strategy for synthetic biology, reporting on social science interviews done with scientists, science journal editors, members of science advisory boards and authors of nongovernmental policy reports on synthetic biology. After summarizing their observations about the potential advantages and disadvantages of the professionalization of synthetic biology, we analyze professionalization as a strategy that overcomes dichotomies found in the current debates about synthetic biology governance, specifically “top down” versus “bottom up” governance and scientific fact versus public values. Professionalization combines community and state, fact and value. Like all governance options, professionalization has limitations, particularly regarding war and peace. It is best conceptualized as potentially part of a wider range of governance mechanisms working in concert: a “web of prevention”.     

Laboratory evolution of peroxide-mediated cytochrome P450 hydroxylation Joo H,Lin Z,Arnold FH. Nature 1999; 399: 670–673

Abstract

The article entitled Laboratory evolution of peroxide-mediated cytochrome P450 hydroxylations, by Hyun Joo, Zhanglin Lin and Francis H. Arnold of the Division of Chemistry and Chemical Engineering, California Institute of Technology, recently communicated in Nature,¹ is an excellent example of the revolution in the biological sciences. We frequently hear that we are in the midst of an informational revolution. If one simply considers the fact that all biological information exists in DNA, it is possible to envision the biological informational revolution. Alternatively, the term technological revolution is applied to the many recent advances in several fields, including the biological sciences. Both the informational and technological revolution can be readily recognized in the article by Joo and colleagues.     

Role of ecologists as consultants in urban planning and design

A methodology is described for the utilization of ecosystem concepts in land-use issues of urban development and urban design. The issues are discussed of utilizing science specialists to develop in-depth understanding of ecosystem structure and function, synthesizing the information into usable form, and communicating the ecosystem knowledge to engineers, architects, landscape architects, and planners. Case studies from Ontario and New York illustrate some of the difficulties and opportunities in this kind of interprofessional work. The issue of identifying who is an ecologist and the related matter of professionalization are then discussed.     

Really taking Darwin seriously: An alternative to Michael Ruse's Darwinian metaethics

Michael Ruse has proposed in his recent book Taking Darwin Seriously and elsewhere a new Darwinian ethics distinct from traditional evolutionary ethics, one that avoids the latter's inadequate accounts of the nature of morality and its failed attempts to provide a naturalistic justification of morality. Ruse argues for a sociobiologically based account of moral sentiments, and an evolutionary based casual explanation of their function, rejecting the possibility of ultimate ethical justification. We find that Ruse's proposal distorts, overextends and weakens both Darwinism and naturalism. So we propose an alternative Darwinian metaethics that both remedies the problems in Ruse's proposal and shows how a Darwinian naturalistic account of the moral good in terms of human fitness avoids the naturalistic fallacy and can provide genuine, even if limited, justifications for substantive ethical claims. Thus, we propose to really take Darwin seriously.The authors are equally responsible for the writing of this paper.     

The botanical neolithic revolution

It is proposed, on the basis of evidence from geological history and paleoclimatology, that annual grasses and legumes did not appear as significant components of the vegetation of Asia until the Neothermal, some 11,000 years B.P. The new combination of environmental factors which then became operative induced a widespread physiological and genetic change from a perennial to an annual habit in ecoclimatic zones in which annual types of ancestral perennials had not earlier occurred in any number. The annual prototypes of the Asian cereals and grain legumes therefore became rather suddenly and abundantly available to primitive man in his still biological ecosystems. Once this botanical revolution had occurred throughout the isoxerothermic zones around the inner cores of Asia, progress towards what came to be called civilizations, based on increasingly economic agricultural ecosystems involving cultivation and domestication of crops, followed in a gradual step-by-step manner.     

H. G. Bronn and the History of Nature

The German paleontologist H. G. Bronn is best remembered for his 1860 translation and critique of Darwin’s Origin of Species, and for supposedly twisting Darwinian evolution into conformity with German idealistic morphology. This analysis of Bronn’s writings shows, however, that far from being mired in an outmoded idealism that confined organic change to predetermined developmental pathways, Bronn had worked throughout the 1840s and 1850s on a new, historical approach to life. He had been moving from the study of plant and animal forms in the abstract towards placing them into geological and biogeographical context, analyzing patterns of progress and adaptation, explaining species diversity and individual variation, and applying biological insights to practical problems such as artificial breeding. Even though Bronn never fully accepted the idea of species transformation, he saw Darwin’s theory as a bold new move toward his own goal of establishing a comprehensive, historical science of life, and he presented it as such in his translation and commentary. Thus Darwin’s ideas gained a quick and generally favorable hearing in Germany not because of their easy assimilability into an older tradition, but because of their appeal to the innovative Bronn.     

A Mathematical Model for Evolution and SETI

Darwinian evolution theory may be regarded as a part of SETI theory in that the factor f_l in the Drake equation represents the fraction of planets suitable for life on which life actually arose. In this paper we firstly provide a statistical generalization of the Drake equation where the factor f_l is shown to follow the lognormal probability distribution. This lognormal distribution is a consequence of the Central Limit Theorem (CLT) of Statistics, stating that the product of a number of independent random variables whose probability densities are unknown and independent of each other approached the lognormal distribution when the number of factors increased to infinity. In addition we show that the exponential growth of the number of species typical of Darwinian Evolution may be regarded as the geometric locus of the peaks of a one-parameter family of lognormal distributions (b-lognormals) constrained between the time axis and the exponential growth curve. Finally, since each b-lognormal distribution in the family may in turn be regarded as the product of a large number (actually “an infinity”) of independent lognormal probability distributions, the mathematical way is paved to further cast Darwinian Evolution into a mathematical theory in agreement with both its typical exponential growth in the number of living species and the Statistical Drake Equation.     

Darwin's error? Patrick Matthew and the catastrophic nature of the geologic record

In 1831, the Scottish horticulturalist Patrick Matthew (1790–1874) published a clear statement of the law of natural selection in an Appendix to his book Naval Timber and Arboriculture, which both Darwin and Wallace later acknowledged. Matthew, however, was a catastrophist, and he presented natural selection within the contemporary view that relatively long intervals of environmental stability were episodically punctuated by catastrophic mass extinctions of life. Modern studies support a similar picture of the division of geologic time into long periods of relative evolutionary stability ended by sudden extinction events. Mass extinctions are followed by recovery intervals during which surviving taxa radiate into vacated niches. This modern punctuated view of evolution and speciation is much more in line with Matthew's episodic catastrophism than the classical Lyellian–Darwinian gradualist view.     

Competitive fitness in experimental populations of Drosophila willistoni

Experiments are reported in which genetically different strains of Drosophila willistoni compete with D. pseudoobscura. The competition was studied at three temperatures, 20°, 22°, and 25°C. The outcome of the competition depends on the genetic constitution of the competing species, but at 25° and 22°C D. willistoni flies are generally stronger competitors than D. pseudoobscura, while at 20°C D. pseudoobscura generally has a competitive advantage. There is a significant interaction between genotype and temperature; the strain RP3 is the weakest competitor of all D. willistoni strains at 22° and 25°C, but not at 20°C; the strain M18 is the best competitor at 20° and 22°C but not at 25°C.The performance of the four strains of D. willistoni was measured in two more ways. First we estimated their Darwinian fitness relative to other genotypes of the same species. Second, we measured the average population size of each strain in pure culture. There is no significant correlation between population size in pure culture and either competitive fitness or Darwinian fitness. There is, however, a strong positive correlation between Darwinian fitness and interspecific competitive fitness.It is pointed out that natural selection leads to an increase in the average Darwinian fitness of a population but not necessarily to an increase in its adaptedness to the environment. Yet the synthetic theory of evolution assumes that the genes and genotypes favored by natural selection are usually those which increase the adaptedness of their carriers to the environments where they live. The correlation between Darwinian fitness and adaptedness needs to be studied experimentally.This work was supported by NSF grant GB-12562 (International Biological Program), AEC contract AT-(30-1)-3096, and PHS Career Development Award K3GM 37265 to F. J. Ayala. The senior author's stay in New York was financed in part by Research Fellowship 2-12861 from the Panamerican Union.     

Minireview: Apoptosis as seen through a lens

The lens represents an ideal model system for studying many of the cellular and molecular events of differentiation. It is composed of two ectodermally-derived cell types: the lens epithelial cells and the lens fibre cells, which are derived from the lens epithelial cells by differentiation. Programmed removal of nuclei and other organelles from the lens fibre cells ensures that an optically clear structure is created, while the morphology of the degenerating nuclei is similar to that observed during apoptosis and is accompanied by DNA fragmentation. These observations suggest the existence of biochemical parallels between the process of lens fibre cell organelle loss and classical apoptosis. For example, proteins encoded by the bcl-2 and caspase gene families are expressed in developing lenses and nuclear degeneration in lens fibre cells can be inhibited in vivo by overexpression of bcl-2 and in vitro by incubation of differentiating lens epithelial cell cultures with caspase inhibitors. Thus, the developing lens may represent a particularly useful model system for researchers interested in apoptosis. In this review, the recent literature pertaining to lens fibre cell organelle loss and its relationship to apoptosis is reviewed and possible future research directions are suggested.     

The Charms of Nature: Darwin on Meaning and Value

I review George Levine’s provocative and highly original book Darwin Loves You. Levine, whose “home discipline” is English Literature, offers a compelling interpretation of Darwin’s works, evaluating their content and Darwin’s prose style to identify a distinctly Darwinian attitude toward nature as a source of meaning and value. Levine believes that Darwin exemplifies the capacity to feel “enchantment” about the natural world, suggesting that, if Darwin’s example were followed, a “Darwinian re-enchantment of the world” would be brought about. This would offer a secular, non-supernatural basis for purpose, meaning, and value. I conclude with a few critical remarks about the scope and cogency of Levine’s proposal.     

Patterns and Processes in Cultural Evolution

Darwinian models of cultural change have been motivated, in part, by the desire to provide a framework for the unification of the biological and the human sciences. In this paper, drawing upon a distinction between the evolution of enabling mechanisms for the acquisition and dissemination of knowledge (EEM) and the evolution of epistemic theses as cultural products (EET), we propose a model of how culture emerges as a product of biological evolution on the basis of the concept of reaction norms. The goal of this model is to provide a means for conceptualizing how the biological and the cultural realms are connected, when they start to disconnect, and what the key transitions are. We then assess the viability of a Darwinian approach to cultural change. We conclude that the prospects of producing a Darwinian model of cultural change that unifies the human sciences in a way that mirrors the unification of the biological sciences in the light of Darwin’s theory are rather dim.     

The uniqueness of biological self-organization: challenging the Darwinian paradigm

Here we discuss the challenge posed by self-organization to the Darwinian conception of evolution. As we point out, natural selection can only be the major creative agency in evolution if all or most of the adaptive complexity manifest in living organisms is built up over many generations by the cumulative selection of naturally occurring small, random mutations or variants, i.e., additive, incremental steps over an extended period of time. Biological self-organization—witnessed classically in the folding of a protein, or in the formation of the cell membrane—is a fundamentally different means of generating complexity. We agree that self-organizing systems may be fine-tuned by selection and that self-organization may be therefore considered a complementary mechanism to natural selection as a causal agency in the evolution of life. But we argue that if self-organization proves to be a common mechanism for the generation of adaptive order from the molecular to the organismic level, then this will greatly undermine the Darwinian claim that natural selection is the major creative agency in evolution. We also point out that although complex self-organizing systems are easy to create in the electronic realm of cellular automata, to date translating in silico simulations into real material structures that self-organize into complex forms from local interactions between their constituents has not proved easy. This suggests that self-organizing systems analogous to those utilized by biological systems are at least rare and may indeed represent, as pre-Darwinists believed, a unique ascending hierarchy of natural forms. Such a unique adaptive hierarchy would pose another major challenge to the current Darwinian view of evolution, as it would mean the basic forms of life are necessary features of the order of nature and that the major pathways of evolution are determined by physical law, or more specifically by the self-organizing properties of biomatter, rather than natural selection.     

Julius Sachs (1868): The father of plant physiology

The year 2018 marks the 150th anniversary of the first publication of Julius von Sachs' (1832–1897) Lehrbuch der Botanik (Textbook of Botany), which provided a comprehensive summary of what was then known about the plant sciences. Three years earlier, in 1865, Sachs produced the equally impressive Handbuch der Experimental‐Physiologie der Pflanzen (Handbook of Experimental Plant Physiology), which summarized the state of knowledge in all aspects of the discipline known today as plant physiology. Both of these books provided numerous insights based on Sachs' seminal experiments. By virtue of a reliance on detailed empirical observation and the rigorous application of chemical and physical principles, it is fair to say that the publication of these two monumental works marked the beginning of what can be called “modern‐day” plant science. Moreover, Sachs' Lehrbuch der Botanik prefigured the ascendance of plant molecular biology and the systems biology of photoautotrophic organisms. Regrettably, many of the insights of this great scientist have been forgotten by the generations who followed. It is only fitting, therefore, that the anniversary of the publication of the Lehrbuch der Botanik and the career of “the father of plant physiology” should be honored and reviewed, particularly because Sachs established the physiology of green organisms as an integral branch of botany and incorporated a Darwinian perspective into plant biology. Here we highlight key insights, with particular emphasis on Sachs' detailed discussion of sexual reproduction at the cellular level and his endorsement of Darwinian evolution.     

Increased understanding of metabolism of secondary plant products frequently generates sketchy and incorrect statements concerning their evolution and function

Secondary plant products perform important functions within the complex interactions between plants and their environment, e.g. as protective agents against pathogens and herbivores, or as attractants for potential pollinators. We are all aware that the enormous diversity of these natural products resulted from evolutionary processes driven by the selection of advantageous properties. However, when these nexuses are mentioned, very often we incline to formulate ‘Plants have acquired the ability to synthesize secondary plant products in order to …’ without realising that such a statement contradicts the Darwinian principles of evolution and corresponds to a Lamarckian view of teleological evolution. One of the major reasons for these automatic and unconscious misapprehensions is because of the ambiguous usage of the term ‘biological function’, which is very often thought to comprise an intention or a special purpose.     

Beyond directed evolution: Darwinian selection as a tool for synthetic biology

Synthetic biology is an engineering approach that seeks to design and construct new biological parts, devices and systems, as well as to re-design existing components. However, rationally designed synthetic circuits may not work as expected due to the context-dependence of biological parts. Darwinian selection, the main mechanism through which evolution works, is a major force in creating biodiversity and may be a powerful tool for synthetic biology. This article reviews selection-based techniques and proposes strict Darwinian selection as an alternative approach for the identification and characterization of parts. Additionally, a strategy for fine-tuning of relatively complex circuits by coupling them to a master standard circuit is discussed.     

Darwin and sexual selection: One hundred years of misunderstanding

Darwin's book on the Descent of Man and Selection in Relation to Sex (1871) is often viewed as the continuation of TheOrigin of Species published 12 years earlier (1859), both because of the implicit parallelism between natural selection and sexual selection, and because Darwin himself presents the book as developing a subject (man) which he intentionally omitted in the Origin. But the Descent can also be viewed as the continuation of his book on Variation published three years earlier (1868). Firstly because Darwin's hypothesis of pangenesis links the selection process to the origin of variation through use and disuse, an idea underlying his speculations on the origin of moral sense in humans. Second because like the action of the horticulturist on his domestic crops, sexual selection exerted by one sex on the other sex can develop fancy traits that are not easily accounted for by their utility to the selected organism itself, such as artistic taste, pride, courage, and the morphological differences between human populations. These traits are difficult to reconcile with pangenesis. They add up to other contradictions of the book possibly resulting from Darwin's erroneous inference about the mechanism of inheritance, like those on the determination of sex-ratio, or the confusion between individual adaptation and the advantage to the species. These inconsistencies inaugurate a weakening of the Darwinian message, which will last 50 years after his death. They contributed to the neglect of sexual selection for a century. Darwin however maintained a logical distinction between evolutionary mechanisms and hereditary mechanisms, and an epistemological distinction between evolutionary theory and Pangenesis hypothesis. In the modern context of Mendelian genetics, Darwin's sexual selection retrospectively appears as luminous an idea in its pure principle as natural selection, even though the mechanisms governing the evolution of sexual choice in animals remain largely unresolved.     

Race,ethnicity and social science

The contours and complexities of race and racism continue to confound the social sciences. This problem originates in the historical complicity of the social science disciplines with the establishment and maintenance of the systems of racial predation, injustice and indeed genocide upon which the modern world was built. All the social sciences originate in raciology and race management, a fact that is rarely acknowledged. A critical reappraisal of ‘mainstream’ social science’s theoretical and methodological approach to race is therefore overdue. The Ethnic and Racial Studies Review is the right venue for this rethinking. Andreas Wimmer’s distinguished oeuvre provides an appropriate ‘case’ of the tendency that this editorial essay seeks to revise. Concentrating on Wimmer’s 2013 Ethnic Boundary Making, whose publication was the subject of a highly laudatory 2014 issue of ERS Review, this essay criticizes the book as an instance of the problematic social science approaches mentioned.