Is there a will to meaning?

All thinking human beings seek an answer to the question, What is the meaning of life? Herein are discussed answers to this question, drawing on various traditions, but especially from Stoicism.

The power of meaning: the quest for an existential roadmap.

Where can we turn to find the story of our lives-an existential roadmap that explains where we have come from, why we are here, and where we are headed? Must each of us discover meaning within the context of our individual lives, or are there universal sources of meaning that we can all access? Is there any relationship between living a meaningful life and the quality of our health and well-being? And how can we find meaning in the face of adversity and suffering? Neurologist Jay Lombard, philosophers Massimo Pigliucci and Michael Ruse, and author Emily Esfahani Smith shed light on these perennial questions in conversation with Steve Paulson, executive producer and host of To the Best of Our Knowledge.

Scientism and Pseudoscience: A Philosophical Commentary.

The term "scientism" is used in a variety of ways with both negative and positive connotations. I suggest that some of these uses are inappropriate, as they aim simply at dismissing without argument an approach that a particular author does not like. However, there are legitimate negative uses of the term, which I explore by way of an analogy with the term "pseudoscience." I discuss these issues by way of a recent specific example provided by a controversy in the field of bioethics concerning the value, or lack thereof, of homeopathy. I then frame the debate about scientism within the broader context of C.P. Snow's famous essay on the "two cultures."

Gould on Morton, Redux: What can the debate reveal about the limits of data?

Lewis et al. (2011) attempted to restore the reputation of Samuel George Morton, a 19th century physician who reported on the skull sizes of different folk-races. Whereas Gould (1978) claimed that Morton's conclusions were invalid because they reflected unconscious bias, Lewis et al. alleged that Morton's findings were, in fact, supported, and Gould's analysis biased. We take strong exception to Lewis et al.'s thesis that Morton was "right." We maintain that Gould was right to reject Morton's analysis as inappropriate and misleading, but wrong to believe that a more appropriate analysis was available. Lewis et al. fail to recognize that there is, given the dataset available, no appropriate way to answer any of the plausibly interesting questions about the "populations" in question (which in many cases are not populations in any biologically meaningful sense). We challenge the premise shared by both Gould and Lewis et al. that Morton's confused data can be used to draw any meaningful conclusions. This, we argue, reveals the importance of properly focusing on the questions asked, rather than more narrowly on the data gathered.

The mismeasure of machine: Synthetic biology and the trouble with engineering metaphors.

The scientific study of living organisms is permeated by machine and design metaphors. Genes are thought of as the "blueprint" of an organism, organisms are "reverse engineered" to discover their functionality, and living cells are compared to biochemical factories, complete with assembly lines, transport systems, messenger circuits, etc. Although the notion of design is indispensable to think about adaptations, and engineering analogies have considerable heuristic value (e.g., optimality assumptions), we argue they are limited in several important respects. In particular, the analogy with human-made machines falters when we move down to the level of molecular biology and genetics. Living organisms are far more messy and less transparent than human-made machines. Notoriously, evolution is an opportunistic tinkerer, blindly stumbling on "designs" that no sensible engineer would come up with. Despite impressive technological innovation, the prospect of artificially designing new life forms from scratch has proven more difficult than the superficial analogy with "programming" the right "software" would suggest. The idea of applying straightforward engineering approaches to living systems and their genomes-isolating functional components, designing new parts from scratch, recombining and assembling them into novel life forms-pushes the analogy with human artifacts beyond its limits. In the absence of a one-to-one correspondence between genotype and phenotype, there is no straightforward way to implement novel biological functions and design new life forms. Both the developmental complexity of gene expression and the multifarious interactions of genes and environments are serious obstacles for "engineering" a particular phenotype. The problem of reverse-engineering a desired phenotype to its genetic "instructions" is probably intractable for any but the most simple phenotypes. Recent developments in the field of bio-engineering and synthetic biology reflect these limitations. Instead of genetically engineering a desired trait from scratch, as the machine/engineering metaphor promises, researchers are making greater strides by co-opting natural selection to "search" for a suitable genotype, or by borrowing and recombining genetic material from extant life forms.

What are we to make of the concept of race? Thoughts of a philosopher-scientist.

Discussions about the biological bases (or lack thereof) of the concept of race in the human species seem to be never ending. One of the latest rounds is represented by a paper by Neven Sesardic, which attempts to build a strong scientific case for the existence of human races, based on genetic, morphometric and behavioral characteristics, as well as on a thorough critique of opposing positions. In this paper I show that Sesardic's critique falls far short of the goal, and that his positive case is exceedingly thin. I do this through a combination of analysis of the actual scientific findings invoked by Sesardic and of some philosophical unpacking of his conceptual analysis, drawing on a dual professional background as an evolutionary biologist and a philosopher of science.

Invasion of diverse habitats by few Japanese knotweed genotypes is correlated with epigenetic differentiation.

The expansion of invasive species challenges our understanding of the process of adaptation. Given that the invasion process often entails population bottlenecks, it is surprising that many invasives appear to thrive even with low levels of sequence-based genetic variation. Using Amplified Fragment Length Polymorphism (AFLP) and methylation sensitive-AFLP (MS-AFLP) markers, we tested the hypothesis that differentiation of invasive Japanese knotweed in response to new habitats is more correlated with epigenetic variation than DNA sequence variation. We found that the relatively little genetic variation present was differentiated among species, with less differentiation among sites within species. In contrast, we found a great deal of epigenetic differentiation among sites within each species and evidence that some epigenetic loci may respond to local microhabitat conditions. Our findings indicate that epigenetic effects could contribute to phenotypic variation in genetically depauperate invasive populations. Deciphering whether differences in methylation patterns are the cause or effect of habitat differentiation will require manipulative studies.

Genotype-phenotype mapping and the end of the 'genes as blueprint' metaphor.

In a now classic paper published in 1991, Alberch introduced the concept of genotype-phenotype (G-->P) mapping to provide a framework for a more sophisticated discussion of the integration between genetics and developmental biology that was then available. The advent of evo-devo first and of the genomic era later would seem to have superseded talk of transitions in phenotypic space and the like, central to Alberch's approach. On the contrary, this paper shows that recent empirical and theoretical advances have only sharpened the need for a different conceptual treatment of how phenotypes are produced. Old-fashioned metaphors like genetic blueprint and genetic programme are not only woefully inadequate but positively misleading about the nature of G-->P, and are being replaced by an algorithmic approach emerging from the study of a variety of actual G-->P maps. These include RNA folding, protein function and the study of evolvable software. Some generalities are emerging from these disparate fields of analysis, and I suggest that the concept of 'developmental encoding' (as opposed to the classical one of genetic encoding) provides a promising computational-theoretical underpinning to coherently integrate ideas on evolvability, modularity and robustness and foster a fruitful framing of the G-->P mapping problem.

An extended synthesis for evolutionary biology.

Evolutionary theory is undergoing an intense period of discussion and reevaluation. This, contrary to the misleading claims of creationists and other pseudoscientists, is no harbinger of a crisis but rather the opposite: the field is expanding dramatically in terms of both empirical discoveries and new ideas. In this essay I briefly trace the conceptual history of evolutionary theory from Darwinism to neo-Darwinism, and from the Modern Synthesis to what I refer to as the Extended Synthesis, a more inclusive conceptual framework containing among others evo-devo, an expanded theory of heredity, elements of complexity theory, ideas about evolvability, and a reevaluation of levels of selection. I argue that evolutionary biology has never seen a paradigm shift, in the philosophical sense of the term, except when it moved from natural theology to empirical science in the middle of the 19th century. The Extended Synthesis, accordingly, is an expansion of the Modern Synthesis of the 1930s and 1940s, and one that--like its predecessor--will probably take decades to complete.

Down with natural selection?

Biologists are increasingly reexamining the conceptual structure of evolutionary theory, which dates back to the so-called Modern Synthesis of the 1930s and 1940s. Calls for an Extended Evolutionary Synthesis (EES) cite a number of empirical and theoretical advances that need to be accounted for, including evolvability, evolutionary novelties, capacitors of phenotypic evolution, developmental plasticity, and phenotypic attractors. In Biological Emergences, however, Robert Reid outlines a theory of evolution in which natural selection plays no role or-worse-actually impedes evolution by what Reid calls "natural experimentation." For Reid, biological complexity emerges because of intrinsic mechanisms that work in opposition to natural selection, a view that would reopen old questions of orthogenesis and Lamarckism. This review outlines why we do need an EES, but also why it is unlikely to take the shape that Reid advocates.

The borderlands between science and philosophy: an introduction.

Science and philosophy have a very long history, dating back at least to the 16th and 17th centuries, when the first scientist-philosophers, such as Bacon, Galilei, and Newton, were beginning the process of turning natural philosophy into science. Contemporary relationships between the two fields are still to some extent marked by the distrust that maintains the divide between the so-called "two cultures." An increasing number of philosophers, however, are making conceptual contributions to sciences ranging from quantum mechanics to evolutionary biology, and a few scientists are conducting research relevant to classically philosophical fields of inquiry, such as consciousness and moral decision-making. This article will introduce readers to the borderlands between science and philosophy, beginning with a brief description of what philosophy of science is about, and including a discussion of how the two disciplines can fruitfully interact not only at the level of scholarship, but also when it comes to controversies surrounding public understanding of science.

Plasticity in salt tolerance traits allows for invasion of novel habitat by Japanese knotweed s. l. (Fallopia japonica and F.xbohemica, Polygonaceae).

Japanese knotweeds are among the most invasive organisms in the world. Their recent expansion into salt marsh habitat provides a unique opportunity to investigate how invasives establish in new environments. We used morphology, cytology, and AFLP genotyping to identify taxa and clonal diversity in roadside and salt marsh populations. We conducted a greenhouse study to determine the ability to tolerate salt and whether salt marsh populations are more salt tolerant than roadside populations as measured by the efficiency of PSII, leaf area, succulence, height, root-to-shoot ratio, and total biomass. Clonal diversity was extremely low with one F. japonica clone and five F. ×bohemica genotypes. The two taxa were significantly different in several traits, but did not vary in biomass or plasticity of any trait. All traits were highly plastic in response to salinity, but differed significantly among genets. Despite this variation, plants from the salt marsh habitats did not perform better in the salt treatment, suggesting that they are not better adapted to tolerate salt. Instead, our data support the hypothesis that plasticity in salt tolerance traits may allow these taxa to live in saline habitats without specific adaptation to tolerate salt.

Is evolvability evolvable?

In recent years, biologists have increasingly been asking whether the ability to evolve--the evolvability--of biological systems, itself evolves, and whether this phenomenon is the result of natural selection or a by-product of other evolutionary processes. The concept of evolvability, and the increasing theoretical and empirical literature that refers to it, may constitute one of several pillars on which an extended evolutionary synthesis will take shape during the next few years, although much work remains to be done on how evolvability comes about.

Epigenetics for ecologists.

There is now mounting evidence that heritable variation in ecologically relevant traits can be generated through a suite of epigenetic mechanisms, even in the absence of genetic variation. Moreover, recent studies indicate that epigenetic variation in natural populations can be independent from genetic variation, and that in some cases environmentally induced epigenetic changes may be inherited by future generations. These novel findings are potentially highly relevant to ecologists because they could significantly improve our understanding of the mechanisms underlying natural phenotypic variation and the responses of organisms to environmental change. To understand the full significance of epigenetic processes, however, it is imperative to study them in an ecological context. Ecologists should therefore start using a combination of experimental approaches borrowed from ecological genetics, novel techniques to analyse and manipulate epigenetic variation, and genomic tools, to investigate the extent and structure of epigenetic variation within and among natural populations, as well as the interrelations between epigenetic variation, phenotypic variation and ecological interactions.