Darwin, nós temos um problema - a teleonomia vai substituir a teleologia na biologia evolutiva?

segunda-feira, maio 08, 2023

Teleonomy: Revisiting a Proposed Conceptual Replacement for Teleology

Max Dresow & Alan C. Love 

Biological Theory (2023)

Abstract

The concept of teleonomy has been attracting renewed attention recently. This is based on the idea that teleonomy provides a useful conceptual replacement for teleology, and even that it constitutes an indispensable resource for thinking biologically about purposes. However, both these claims are open to question. We review the history of teleological thinking from Greek antiquity to the modern period to illuminate the tensions and ambiguities that emerged when forms of teleological reasoning interacted with major developments in biological thought. This sets the stage for an examination of Pittendrigh’s (Adaptation, natural selection, and behavior. In: Roe A, Simpson GG (eds) Behavior and evolution. Yale University Press, New Haven, pp 390–416, 1958) introduction of “teleonomy” and its early uptake in the work of prominent biologists. We then explore why teleonomy subsequently foundered and consider whether the term may yet have significance for discussions of goal-directedness in evolutionary biology and philosophy of science. This involves clarifying the relationship between teleonomy and teleological explanation, as well as asking how the concept of teleonomy impinges on research at the frontiers of evolutionary theory.

FREE PDF GRATIS: Biological Theory

Alô Academia Brasileira de Ciências: mais uma tempestade se aproxima na teoria da evolução.

terça-feira, maio 02, 2023

An approaching storm in evolutionary theory 

Review of: Rereading Darwin’s Origin of Species: The Hesitations of an Evolutionist, by Richard G. Delisle and James Tierney,  2022.  Bloomsbury Academic, London. 176 pp. ISBN: 9781350259577

Alexander Czaja

Evolution, Volume 77, Issue 4, 1 April 2023, Pages 1170–1172, https://doi.org/10.1093/evolut/qpad009

Published: 26 January 2023

For about 10 years, something important has been brewing in the world of evolution, a great storm that, unfortunately, has so far only made itself felt among a few biologists, historians, and philosophers of biology and evolution (Jablonka & Lamb, 2005, 2020; Laland et al., 2014; Müller, 2017; Pigliucci & Müller, 2010; Skinner, 2015). Reading the work of most practicing biologists, one hardly sees any sign of this gathering storm. On the contrary, in standard textbooks and popular literature, no winds of resistance have been felt, and the ship known as the Modern Theory of Evolution (MTE) sails safely and undisturbed from its usual academic course. It remains to be seen how strong the storm will ultimately be.

One recent manifestation of this storm is the new book Rereading Darwin’s Origin of Species by Richard G. Delisle and James Tierney, a short read aimed at reaching a larger audience. Delisle is a paleoanthropologist who also holds a PhD in philosophy. His co-author, James Tierney, studied philosophy at the University of Chicago and is currently Director of the English Language Program at Yale University.

To get straight to the point: The book has no intention of capsizing the MTE ship or to unseating the modern theory but puts forth some provocative theses against the generally accepted view that Darwin was the first modern evolutionary thinker in history: the authors try to demonstrate that there is a wide gap between Darwin and evolutionists today. The most daring of their theses states that Darwin was not an evolutionist in the modern sense of the word. Indeed, the authors question the appropriation of Darwin by proponents of the MTE, who have always placed him and his Origin of Species at the conceptual center of their own model. The book provides compelling arguments that the MTE is based on a highly distorted and anachronistic picture of Darwin, both of his time and main work. Having set forth their case for a fresh look at the Origin, the authors delve deep and meticulously in Darwin’s main work, by uncovering its neglected ambiguities and contradictions. After years of collective Darwin euphoria, in which—as the authors self-critically note—they themselves actively participated, it is now time for a more critical approach. The authors call it “returning Darwin to the human dimension” (p. x) and they wonder “[w]hy has it taken so long for us to realize that Darwin’s commitment to evolutionism was incomplete?” (p. 6).

...

FREE PDF GRATIS: Evolution

Dicas químicas podem ter possibilitado o surgimento da multicelularidade

segunda-feira, maio 01, 2023

Chemical factors induce aggregative multicellularity in a close unicellular relative of animals

Núria Ros-Rocher, Ria Q. Kidner, Catherine Gerdt, +2, and Joseph P. Gerdt 

Authors Info & Affiliations

Edited by Joan Strassmann, Washington University in St. Louis, St. Louis, MO; received November 30, 2022; accepted February 14, 2023

April 24, 2023

120 (18) e2216668120

https://doi.org/10.1073/pnas.2216668120  



Significance

Whether the first multicellular animals utilized chemical cues to regulate cellular aggregation remains poorly studied. We discovered that aggregation of a unicellular close animal relative is induced by chemical cues, as observed in some animals and other unicellular species. This discovery expands the prevalence of chemically regulated multicellularity in unicellular animal relatives, which suggests that this trait may have been common in the close unicellular ancestors of animals. Our findings also yield a biochemical tool to further dissect the stages of aggregation in an emerging unicellular model and determine the extent of their homology to aggregation mechanisms in animals.

Abstract

Regulated cellular aggregation is an essential process for development and healing in many animal tissues. In some animals and a few distantly related unicellular species, cellular aggregation is regulated by diffusible chemical cues. However, it is unclear whether regulated cellular aggregation was part of the life cycles of the first multicellular animals and/or their unicellular ancestors. To fill this gap, we investigated the triggers of cellular aggregation in one of animals’ closest unicellular living relatives—the filasterean Capsaspora owczarzaki. We discovered that Capsaspora aggregation is induced by chemical cues, as observed in some of the earliest branching animals and other unicellular species. Specifically, we found that calcium ions and lipids present in lipoproteins function together to induce aggregation of viable Capsaspora cells. We also found that this multicellular stage is reversible as depletion of the cues triggers disaggregation, which can be overcome upon reinduction. Our finding demonstrates that chemically regulated aggregation is important across diverse members of the holozoan clade. Therefore, this phenotype was plausibly integral to the life cycles of the unicellular ancestors of animals.

FREE PDF GRATIS: PNAS Sup. Info.

Darwin, nós temos um problema: árvores evolutivas baseadas na anatomia podem estar erradas.

Molecular phylogenies map to biogeography better than morphological ones
Jack W. Oyston, Mark Wilkinson, Marcello Ruta & Matthew A. Wills 
Communications Biology volume 5, Article number: 521 (2022)

Image/Imagem: fabelacorrea / Adobe Sto


Abstract

Phylogenetic relationships are inferred principally from two classes of data: morphological and molecular. Currently, most phylogenies of extant taxa are inferred from molecules and when morphological and molecular trees conflict the latter are often preferred. Although supported by simulations, the superiority of molecular trees has rarely been assessed empirically. Here we test phylogenetic accuracy using two independent data sources: biogeographic distributions and fossil first occurrences. For 48 pairs of morphological and molecular trees we show that, on average, molecular trees provide a better fit to biogeographic data than their morphological counterparts and that biogeographic congruence increases over research time. We find no significant differences in stratigraphic congruence between morphological and molecular trees. These results have implications for understanding the distribution of homoplasy in morphological data sets, the utility of morphology as a test of molecular hypotheses and the implications of analysing fossil groups for which molecular data are unavailable.

FREE PDF GRATIS: Communications Biology

60 anos de silêncio revela insights em busca de vida extraterrestre.

Inferring the Rate of Technosignatures from 60 yr of Nondetection

Claudio Grimaldi1,2

Published 2023 April 13 • © 2023. The Author(s). Published by the American Astronomical Society.

The Astronomical Journal, Volume 165, Number 5

Citation Claudio Grimaldi 2023 AJ 165 199

DOI 10.3847/1538-3881/acc327

Image/Imagem: Deviant Art

Abstract

For about the last 60 yr the search for extraterrestrial intelligence has been monitoring the sky for evidence of remotely detectable technological life beyond Earth, with no positive results to date. While the lack of detection can be attributed to the highly incomplete sampling of the search space, technological emissions may be actually rare enough that we are living in a time when none cross the Earth. Here we explore the latter possibility and derive the likelihood of the Earth not being crossed by signals for at least the last 60 yr to infer upper bounds on their rate of emission. Under the assumption that technological emitters are distributed uniformly in the Milky Way and that they generate technoemissions at a constant rate, we find less than about one to five emissions generated per century with 95% credible level. This implies optimistic waiting times until the next crossing event of no less than 60–1800 yr with a 50% probability. A significant fraction of highly directional signals increases the emission rates' upper bounds, but without systematically changing the waiting time. Although these probabilistic bounds are derived from a specific model and their validity depends on the model's assumptions, they are nevertheless quite robust against weak time dependences of the emission rate or nonuniform spatial distributions of the emitters. Our results provide therefore a benchmark for assessing the lack of detection and may serve as a basis to form optimal strategies for the search for extraterrestrial intelligence.

FREE PDF GRATIS: The Astronomical Journal

A Academia Brasileira de Ciências não cientificamente eleva a evolução como dogma que não pode ser criticado!

domingo, abril 16, 2023

 

ACADEMIA BRASILEIRA DE CIÊNCIAS E A EVOLUÇÃO DAS ESPÉCIES

A Academia Brasileira de Ciências (ABC) é uma associação de direito privado sem fins econômicos, fundada em 3 de maio de 1916 por 44 eminentes cientistas das áreas de ciências matemáticas, ciências fisicoquímicas e ciências biológicas com o objetivo de contribuir para o desenvolvimento da ciência e da tecnologia, da educação e do bem-estar social do Brasil. A Academia hoje atua nas seguintes áreas especializadas do conhecimento: Ciências Matemáticas, Ciências Físicas, Ciências Químicas, Ciências da Terra, Ciências Biológicas, Ciências Biomédicas, Ciências da Saúde; Ciências Agrárias, Ciências da Engenharia, e Ciências Sociais. De acordo com seu estatuto, “as atividades da Academia serão desenvolvidas com fiel observância aos princípios da legalidade, impessoalidade, moralidade e economicidade, com ampla publicidade dos seus atos, projetos e missões”.

A ABC tem como base filosófica o Estado Democrático de Direito, a separação entre ciência e religião, a laicidade do Estado, a não participação da instituição em partidos políticos, os direitos humanos, a sustentabilidade e o meio ambiente, sempre pautando suas ações pela ética e transparência e as melhores evidências científicas disponíveis.

A ABC não compactua com criacionismo ou desenho inteligente. A ciência baseia-se em evidências e observações empíricas testáveis, é dependente de métodos científicos, da compilação de dados. A ciência busca explicar fenômenos pela avaliação, comprovação e experimentação, e está sempre em desenvolvimento.

A evolução é o princípio fundamental da ciência moderna e inclui a formação do universo, do sistema solar e da Terra, e as condições adequadas para a evolução biológica na Terra. Como referido pela Academia Nacional de Ciências dos Estados Unidos, “a descoberta e compreensão dos processos de evolução representam uma das conquistas mais poderosas da história da ciência”.

A Academia Brasileira de Ciências vem reiterar suas posições e comunicar que estará lançando no início de junho deste ano o livro “A Evolução da Vida na Terra” no qual são apresentados diferentes aspectos da Evolução das Espécies, em uma linguagem acessível ao público em geral. A ABC espera com a publicação desse livro esclarecer a contribuição da ciência para uma sociedade com equidade social, sustentável, mostrando que entender a evolução nos ajuda a resolver problemas biológicos que afetam nossas vidas hoje, tais como saúde, segurança alimentar e inteligência artificial.

Brasil, 14 de abril de 2023.

Academia Brasileira de Ciências


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NOTA DESTE BLOGGER: Aguarde réplica desta nota da ABC por este blogger.

A Física Biológica Chega à Maioridade

sexta-feira, abril 14, 2023

APS News

April 2023 (Volume 32, Number 4)

Opinion: Biological Physics Comes of Age

Once an awkward confrontation between disciplines, biological physics is having its moment — and showing that life is not just a mess.


By William Bialek | March 16, 2023

Physics and biology were not always separate disciplines. In the 18th century, controversy about “animal electricity” proved foundational for the understanding of electricity more generally. In the 19th century, explorations of vision and hearing intermingled with the emerging understanding of optics and acoustics. In the 20th century, the chasm between physics and biology grew wider, but there were spectacular bridges. Most famously, the work that launched our modern view of life — structures of DNA and proteins, theories of base pairing and the genetic code — was done primarily in physics departments.

The revolutionary successes of (re-)connecting physics with biology in the mid-20th century completely changed how we think about life, and even changed how biologists’ work is organized. What emerged first was called molecular biology, and over the course of a generation the ideas and methods of molecular biology — grounded in physics — touched almost every part of the biological sciences. In contrast, physics itself was left relatively untouched.

Although the interaction of physics and biology did not immediately change the trajectory of physics, a small stream of physicists continued to be fascinated by the phenomena of life. I began to be (dimly) aware of all this as a student in the late 1970s. For me, the things biologists talked about were interesting, but the way they talked about them was unsatisfying. Physics was the other way: the style of thinking was attractive, and the theories elegant and powerful, but I never had an original idea about problems in the field’s traditional core. It was clear that physicists were doing all sorts of interesting things connected to the living world, but these efforts didn’t cohere into a community and certainly not into a recognizable branch of physics. We went to meetings where (mostly) we would find biologists working on the same systems, but not physicists asking the same kinds of questions.

...

Read more here: APS News

Matemáticos finalmente descobriram um elusivo azulejo 'einstein'.

quinta-feira, março 30, 2023

An aperiodic monotile

David Smith, Joseph Samuel Myers, Craig S. Kaplan, Chaim Goodman-Strauss

Image/Imagem: Science News


A longstanding open problem asks for an aperiodic monotile, also known as an "einstein": a shape that admits tilings of the plane, but never periodic tilings. We answer this problem for topological disk tiles by exhibiting a continuum of combinatorially equivalent aperiodic polygons. We first show that a representative example, the "hat" polykite, can form clusters called "metatiles", for which substitution rules can be defined. Because the metatiles admit tilings of the plane, so too does the hat. We then prove that generic members of our continuum of polygons are aperiodic, through a new kind of geometric incommensurability argument. Separately, we give a combinatorial, computer-assisted proof that the hat must form hierarchical -- and hence aperiodic -- tilings.

FREE PDF GRATIS: arXiv

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"einstein": is a 13-sided shape called ‘the hat’ forms a pattern that never repeats/é uma configuração de 13 lados chamada 'o chapéu' formando um padrão que nunca se repete.


Nanomotores biológicos rotativos: mero acaso, fortuita necessidade ou design inteligente?

sábado, março 25, 2023

Front. Microbiol., 21 September 2022

Sec. Microbial Physiology and Metabolism

Volume 13 - 2022 | https://doi.org/10.3389/fmicb.2022.1012681



Editorial: Biological rotary nanomotors

Michael D. Manson1*, Beiyan Nan1, Pushkar P. Lele2, Jun Liu3 and Thomas M. Duncan4

1Department of Biology, Texas A&M University, College Station, TX, United States

2Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, United States

3Microbial Sciences Institute, Department of Microbial Pathogenesis, Yale University, New Haven, CT, United States

4Department of Biochemistry & Molecular Biology, Upstate Medical University, Syracuse, NY, United States

Editorial on the Research Topic

Biological rotary nanomotors

This Research Topic of 20 review articles covers the incredible variety of molecular rotary nanomachines that have evolved over billions of years. The details of their molecular mechanisms are well-known for the Bacterial Flagellar Motor (BFM) and FoF1 ATP synthase/ATPase. They are inferred by analogy to the BFM for others: the 5:2 motors of gliding bacteria and the 5:2 motors of the Ton and Tol systems that govern events at the outer membrane of gram-negative bacteria. All of these systems couple a transmembrane ion motive force to useful work. Two additional articles consider the unique propulsion generator of the Archaea, the archaellum, which appears to be driven entirely by ATP hydrolysis and has an evolutionary history completely independent of those for the 5:2 motors and FoF1.

This Research Topic originated with Mike Manson, who was inspired by the recently published structures of 5:2 rotary motors and the desire to create a fitting tribute to Howard Berg, who introduced rotary motors into biology. The effort was augmented by recruitment of Tom Duncan, Pushkar Lele, Jun Liu, and Beiyan Nan, who possess the expertise to select the authors best able to tell the story of rotary nanomotors and to edit their contributions.

The Research Topic has six sections. The first two chapters serve as an introduction to the history, structure, and energetics of rotary motors driven by an ion motive force. The second of these provides a detailed consideration of the structure of 5:2 rotary motors and how their function and energetics compare with the Fo motor of ATP synthases, which has a gearing ratio ranging from 8:1 to 15:1 in different species. The next seven articles provide detailed reviews about different aspects and incarnations of BFMs. The following two articles discuss the function of ion-powered motors in gliding bacteria, which do not depend on flagella. Next, two reviews cover the Exb/Ton and Tol/Pal systems, both of which are driven by 5:2-type motors. As a segue into the FoF1 motors that drive ATP synthesis, the next two articles cover the archaellum, a helical propeller like the bacterial flagellum, but one driven by ATP hydrolysis rather than an ion motive force and possessing a completely different evolutionary trajectory. The last five articles review different aspects of what is known about the FoF1 ATP synthase, a crucial and ubiquitous energy-transducing enzyme that couples two rotary motor devices.

The editors thank all 49 authors who generously agreed to put their collective knowledge about rotary nanomotors into words. They represent the leading research groups worldwide studying rotary molecular machines. The positive responses to our invitations were doubtless aided by the recognition that this was a tribute to the visionary insight of Howard Berg, whose paper with Robert Anderson in 1973 first declared that “Bacteria Swim by Rotating Helical Filaments.”

We hoped that Howard would write an introduction to this Research Topic. Unfortunately, he passed away on December 30, 2021, just as it became clear that our vision was going to become reality. That sad event adds both poignancy and timeliness to this Research Topic. We also want to thank the four editors who supplemented the efforts of the five designated guest editors mentioned above and the 33 reviewers who, together with the guest editors, ensured that everything presented in the reviews was as clear, complete, and accurate as possible.

We hope this Research Topic serves as a fitting tribute to Howard Berg, the unconventional intellect whose insight ushered in an entire field of molecular biophysics: the study of rotary molecular motors. Savor what is presented here and anticipate the new revelations which doubtless await in the coming years.

FREE FULL SPECIAL ISSUE/EDIÇAO ESPECIAL GRÁTIS: Frontiers in Microbiology

Controlando a sinalização periódica de longo alcance para conduzir uma transição morfogenética: mero acaso, fortuita necessidade ou design inteligente?

quinta-feira, março 23, 2023

Controlling periodic long-range signalling to drive a morphogenetic transition

Hugh Z Ford, Angelika Manhart, Jonathan R Chubb 

Laboratory for Molecular Cell Biology and Department of Cell and Developmental Biology, University College London, United Kingdom; Department of Mathematics, University College London, United Kingdom; Faculty of Mathematics, University of Vienna, Austria

Mar 1, 2023

https://doi.org/10.7554/eLife.83796 

Image/Imagem: Spiral tip circulation and spiral wave progression.

Abstract

Cells use signal relay to transmit information across tissue scales. However, the production of information carried by signal relay remains poorly characterised. To determine how the coding features of signal relay are generated, we used the classic system for long-range signalling: the periodic cAMP waves that drive Dictyostelium collective migration. Combining imaging and optogenetic perturbation of cell signalling states, we find that migration is triggered by an increase in wave frequency generated at the signalling centre. Wave frequency is regulated by cAMP wave circulation, which organises the long-range signal. To determine the mechanisms modulating wave circulation, we combined mathematical modelling, the general theory of excitable media, and mechanical perturbations to test competing models. Models in which cell density and spatial patterning modulate the wave frequency cannot explain the temporal evolution of signalling waves. Instead, our evidence leads to a model where wave circulation increases the ability for cells to relay the signal, causing further increase in the circulation rate. This positive feedback between cell state and signalling pattern regulates the long-range signal coding that drives morphogenesis.

Editor's evaluation

This fundamental work substantially advances our understanding of how multicellular structures transmit information over long ranges. Compelling approaches combining experiments and theory unravel the mechanism by which amoeba form migrating cellular waves by chemotaxis. The work will be of broad interest to cell and developmental biologists.

https://doi.org/10.7554/eLife.83796.sa0

FREE PDF GRATIS: eLife

Darwin, nós tivemos um problema: as ilusões da Síntese Moderna!

terça-feira, março 21, 2023

The Illusions of the Modern Synthesis

Denis Noble 

Biosemiotics volume 14, pages5–24 (2021)


Image/Imagem: The Guardian

Abstract

The Modern Synthesis has dominated biology for 80 years. It was formulated in 1942, a decade before the major achievements of molecular biology, including the Double Helix and the Central Dogma. When first formulated in the 1950s these discoveries and concepts seemed initially to completely justify the central genetic assumptions of the Modern Synthesis. The Double Helix provided the basis for highly accurate DNA replication, while the Central Dogma was viewed as supporting the Weismann Barrier, so excluding the inheritance of acquired characteristics. This article examines the language of the Modern Synthesis and reveals that it is based on four important misinterpretations of what molecular biology had shown, so forming the basis of the four Illusions: 1. Natural Selection; 2. The Weismann Barrier; 3. The Rejection of Darwin’s Gemmules; 4. The Central Dogma. A multi-level organisation view of biology avoids these illusions through the principle of biological relativity. Molecular biology does not therefore confirm the assumptions of the Modern Synthesis.

FREE PDF GRATIS: Biosemiotics

O que há de errado com a causalidade evolutiva?

segunda-feira, março 20, 2023

What’s Wrong with Evolutionary Causation?

Jan Baedke 

Acta Biotheoretica volume 69, pages79–89 (2021)

Image/Imagem: MIT Press


Abstract

This review essay reflects on recent discussions in evolutionary biology and philosophy of science on the central causes of evolution and the structure of causal explanations in evolutionary theory. In this debate, it has been argued that our view of evolutionary causation should be rethought by including more seriously developmental causes and causes of the individual acting organism. I use Tobias Uller’s and Kevin Laland’s volume Evolutionary Causation as well as recent reviews of it as a starting point to reflect on the causal role of agency, individuality, and the environment in evolution. In addition, I critically discuss classical philosophical frameworks of theory change (i.e. Popper’s, Kuhn’s and Lakatos’) used in this debate to understand changing views of evolutionary causation.

FREE PDF GRATIS: Acta Biotheoretic

A síntese evolutiva estendida acarreta poder explicativo ampliado?

Does the extended evolutionary synthesis entail extended explanatory power?

volume
35, Article number: 20 (2020)



Abstract

Biologists and philosophers of science have recently called for an extension of evolutionary theory. This so-called ‘extended evolutionary synthesis’ (EES) seeks to integrate developmental processes, extra-genetic forms of inheritance, and niche construction into evolutionary theory in a central way. While there is often agreement in evolutionary biology over the existence of these phenomena, their explanatory relevance is questioned. Advocates of EES posit that their perspective offers better explanations than those provided by ‘standard evolutionary theory’ (SET). Still, why this would be the case is unclear. Usually, such claims assume that EES’s superior explanatory status arises from the pluralist structure of EES, its different problem agenda, and a growing body of evidence for the evolutionary relevance of developmental phenomena (including developmental bias, inclusive inheritance, and niche construction). However, what is usually neglected in this debate is a discussion of what the explanatory standards of EES actually are, and how they differ from prevailing standards in SET. In other words, what is considered to be a good explanation in EES versus SET? To answer this question, we present a theoretical framework that evaluates the explanatory power of different evolutionary explanations of the same phenomena. This account is able to identify criteria for why and when evolutionary explanations of EES are better than those of SET. Such evaluations will enable evolutionary biology to find potential grounds for theoretical integration.


FREE PDF GRATIS: Biology & Philosophy

Colocando a inferência à melhor explicação no contexto.

terça-feira, fevereiro 28, 2023

Putting inference to the best explanation into context

Leah Henderson

University of Groningen, Oude Boteringestraat 52, Groningen, 9712 GL, the Netherlands

Available online 1 July 2022, Version of Record 1 July 2022.

https://doi.org/10.1016/j.shpsa.2022.06.009 

Image/Imagem

Abstract

It is often assumed that Inference to the Best Explanation, or ‘IBE’, belongs to the context of justification. But several recent developments might lead one to ask whether it is more appropriate to situate it in the context of pursuit. Peircean abduction, which has been designated as an immediate precursor to IBE, is, according to recent scholarship, best located in the context of discovery and pursuit, rather than justification. Furthermore, alleged difficulties in reconciling IBE with Bayesianism have led to a proposal for giving IBE a non-justificatory role, which is close to that of pursuit. I argue, however, that these considerations do not make a strong case for locating IBE in the context of pursuit. Although abduction plays an important role in the context of pursuit, IBE is not simply a renaming of abduction. It has been reconceptualised in a way which makes it unsuitable to operate in the context of pursuit. Considerations concerning the compatibility between IBE and Bayesianism also do not give strong grounds to locate IBE outside the context of justification. This is because we should not expect that the context of justification can be characterised in purely probabilistic terms. Thus IBE should continue to be regarded as a candidate for characterising epistemic appraisal in the context of justification.

Keywords Inference to the best explanationAbductionPeirceContext of justificationContext of pursuit

FREE PDF GRATIS: Studies in History and Philosophy of Science

Inerência e agência na origem e evolução das funções biológicas

sexta-feira, fevereiro 24, 2023

Inherency and agency in the origin and evolution of biological functions 

Stuart A Newman

Biological Journal of the Linnean Society

https://doi.org/10.1093/biolinnean/blac109

Published: 14 September 2022


Image/Imagem

Abstract

Although discussed by 20th century philosophers in terms drawn from the sciences of non-living systems, in recent decades biological function has been considered in relationship to organismal capability and purpose. Bringing two phenomena generally neglected in evolutionary theory (i.e. inherency and agency) to bear on questions of function leads to a rejection of the adaptationist ‘selected effects’ notion of biological function. I review work showing that organisms such as the placozoans can thrive with almost no functional embellishments beyond those of their constituent cells and physical properties of their simple tissues. I also discuss work showing that individual tissue cells and their artificial aggregates exhibit agential behaviours that are unprecedented in the histories of their respective lineages. I review findings on the unique metazoan mechanism of developmental gene expression that has recruited, during evolution, inherent ancestral cellular functionalities into specialized cell types and organs of the different animal groups. I conclude that most essential functions in animal species are inherent to the cells from which they evolved, not selected effects, and that many of the others are optional ‘add-ons’, a status inimical to fitness-based models of evolution positing that traits emerge from stringent cycles of selection to meet external challenges.

Key words adaptationism, biobots, causal role, cell types, fitness, function, appropriation engine, niche construction, placozoans, selected effects

FREE PDF GRATIS: Biological Journal of the Linnean Society

Definindo o cenário geológico para a origem da vida e as questões em aberto contínuas sobre seu surgimento

domingo, fevereiro 19, 2023

Setting the geological scene for the origin of life and continuing open questions about its emergence

Frances Westall 1*, André Brack 1, Alberto G. Fairén 2,3 and Mitchell D. Schulte 4

1Centre de Biophysique Moléculaire, CNRS, Orléans, France
2Centro de Astrobiología (CAB, CSIC-INTA), Madrid, Spain
3Cornell University, Ithaca, NY, United States
4NASA Headquarters, Washington, DC, United States


Image/Imagem: eos.org

Abstract

The origin of life is one of the most fundamental questions of humanity. It has been and is still being addressed by a wide range of researchers from different fields, with different approaches and ideas as to how it came about. What is still incomplete is constrained information about the environment and the conditions reigning on the Hadean Earth, particularly on the inorganic ingredients available, and the stability and longevity of the various environments suggested as locations for the emergence of life, as well as on the kinetics and rates of the prebiotic steps leading to life. This contribution reviews our current understanding of the geological scene in which life originated on Earth, zooming in specifically on details regarding the environments and timescales available for prebiotic reactions, with the aim of providing experimenters with more specific constraints. Having set the scene, we evoke the still open questions about the origin of life: did life start organically or in mineralogical form? If organically, what was the origin of the organic constituents of life? What came first, metabolism or replication? What was the time-scale for the emergence of life? We conclude that the way forward for prebiotic chemistry is an approach merging geology and chemistry, i.e., far-from-equilibrium, wet-dry cycling (either subaerial exposure or dehydration through chelation to mineral surfaces) of organic reactions occurring repeatedly and iteratively at mineral surfaces under hydrothermal-like conditions.

A Síntese Evolutiva Estendida: o que é o debate e como pode ser o sucesso dos que querem sua extensão

quarta-feira, fevereiro 15, 2023

The Extended Evolutionary Synthesis: what is the debate about, and what might success for the extenders look like? 

Tim Lewens

Biological Journal of the Linnean Society, Volume 127, Issue 4, August 2019, Pages 707–721, https://doi.org/10.1093/biolinnean/blz064

Published: 21 May 2019


Abstract

Debate over the Extended Evolutionary Synthesis (EES) ranges over three quite different domains of enquiry. Protagonists are committed to substantive positions regarding (1) empirical questions concerning (for example) the properties and prevalence of systems of epigenetic inheritance; (2) historical characterizations of the modern synthesis; and (3) conceptual/philosophical matters concerning (among other things) the nature of evolutionary processes, and the relationship between selection and adaptation. With these different aspects of the debate in view, it is possible to demonstrate the range of cross-cutting positions on offer when well-informed evolutionists consider their stance on the EES. This overview of the multiple dimensions of debate also enables clarification of two philosophical elements of the EES debate, regarding the status of niche-construction and the role of selection in explaining adaptation. Finally, it points the way to a possible resolution of the EES debate, via a pragmatic approach to evolutionary enquiry.

Key words Darwin, evolution, modern synthesis, neoDarwinism

FREE PDF GRATIS: Biological Journal of the Linnean Society

Dimensões do elétron

Electron Dimensions

Relly Victoria Virgil Petrescu1, Raffaella Aversa2, Shuhui Li3, Ronald Bucinell4, Samuel P. Kozaitis5, Taher M. Abu-Lebdeh6, Antonio Apicella2 and Florian Ion Tiberiu Petrescu1

1 Bucharest Polytechnic University, Romania

2 Second University of Naples, Italy

3 University of Alabama, United States

4 Union College, United States

5 Florida Institute of Technology, United States

6 North Carolina A and T State University, United States


Imagem/Image

Abstract

In this study, the theoretical principles necessary to determine the exact magnitude of a moving electron, depending on the speed of movement, will be exposed. The equations are specifically discussed to determine the radius R of the moving electron, which refers to the electron movement velocity v and the resting mass m0. The mechanical moment of inertia of a sphere around one of its diameters is determined by the relationship between the total kinetic energy of a moving electron as the sum of the two components (translatable and rotating). Using the theory of Louis de Broglie, which shows impulse preservation, the wavelength (associated with the particle) was calculated. The wave frequency (associated with the moving electron) was determined and the moving electron kinetic energy was estimated by decreasing the total resting energy of the electron from the total energy of the moving electrons.

FREE PDF GRATIS: American Journal of Engineering and Applied Sciences

Mais uma evidência de preservação bioquímica óssea endógena em espécime de Tyrannosaurus rex

sábado, fevereiro 11, 2023

 Independent Evidence for the Preservation of Endogenous Bone Biochemistry in a Specimen of Tyrannosaurus rex

by Jennifer Anné 1,*,Aurore Canoville 2,Nicholas P. Edwards 3ORCID,Mary H. Schweitzer 4,5,6 andLindsay E. Zanno 4,5

The Children’s Museum of Indianapolis, Indianapolis, IN 46208, USA

Stiftung Schloss Friedenstein Gotha, 99867 Gotha, Germany

Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA

Department of Biological Sciences, Campus Box 7617, North Carolina State University, Raleigh, NC 27695, USA

Paleontology, North Carolina Museum of Natural Sciences, 11 W. Jones St., Raleigh, NC 27601, USA

Department of Geology, Lund University, Sölvegatan 12, 223 62 Lund, Sweden

Author to whom correspondence should be addressed.

Biology 2023, 12(2), 264; https://doi.org/10.3390/biology12020264

Received: 29 December 2022 / Revised: 3 February 2023 / Accepted: 4 February 2023 / Published: 7 February 2023

(This article belongs to the Special Issue Paleontology in the 21st Century)

The Tyrannosaurus rex fossil known as Stan is displayed in a gallery at Christie’s auction house in New York City on September 17, 2020.

Photograph by Spencer Platt, Getty Images

Simple Summary

Our understanding of what can preserve in the fossil record, and for how long, is constantly evolving with the use of new scientific techniques and exceptional fossil discoveries. In this study, we examine the state of preservation of a Tyrannosaurus rex that died about 66 million years ago. This specimen has previously been studied using a number of advanced methods, all of which have indicated preservation of original soft tissues and bone biomolecules. Here, we use synchrotron—a type of particle accelerator—analyses to generate data identifying and quantifying elements that constitute this fossil bone. We show that trace elements incorporated by the living animal during bone deposition and remodeling, such as zinc, are preserved in the fossil bone in a pattern similar to what is seen in modern bird bones. This pattern is not observed in a microscopically well preserved, but molecularly more degraded dinosaur, a herbivorous Tenontosaurus. These data further support the preservation of original biological material in this T. rex, suggesting new possibilities for deciphering extinct species life histories. This study also highlights that preservation of original biochemistry in fossils is specimen-specific and cannot be determined by pristine appearance alone.

Abstract

Biomolecules preserved in deep time have potential to shed light on major evolutionary questions, driving the search for new and more rigorous methods to detect them. Despite the increasing body of evidence from a wide variety of new, high resolution/high sensitivity analytical techniques, this research is commonly met with skepticism, as the long standing dogma persists that such preservation in very deep time (>1 Ma) is unlikely. The Late Cretaceous dinosaur Tyrannosaurus rex (MOR 1125) has been shown, through multiple biochemical studies, to preserve original bone chemistry. Here, we provide additional, independent support that deep time bimolecular preservation is possible. We use synchrotron X-ray fluorescence imaging (XRF) and X-ray absorption spectroscopy (XAS) to investigate a section from the femur of this dinosaur, and demonstrate preservation of elements (S, Ca, and Zn) associated with bone remodeling and redeposition. We then compare these data to the bone of an extant dinosaur (bird), as well as a second non-avian dinosaur, Tenontosaurus tilletti (OMNH 34784) that did not preserve any sign of original biochemistry. Our data indicate that MOR 1125 bone cortices have similar bone elemental distributions to that of an extant bird, which supports preservation of original endogenous chemistry in this specimen.

Keywords: synchrotron; bone remodeling; elemental analysis; molecular paleontology; diagenetic alteration

FREE PDF GRATIS: Biology

Progresso científico: por quem ou para quem?

quinta-feira, fevereiro 09, 2023

 Scientific progress: By-whom or for-whom?

Finnur Dellsén a b

a University of Iceland, Iceland

b Inland Norway University of Applied Sciences, Norway

Received 20 September 2022, Revised 24 October 2022, Available online 8 December 2022, Version of Record 8 December 2022.

https://doi.org/10.1016/j.shpsa.2022.11.006  

Abstract

When science makes cognitive progress, who or what is it that improves in the requisite way? According to a widespread and unchallenged assumption, it is the cognitive attitudes of scientists themselves, i.e. the agents by whom scientific progress is made, that improve during progressive episodes. This paper argues against this assumption and explores a different approach. Scientific progress should be defined in terms of potential improvements to the cognitive attitudes of those for whom progress is made, i.e. the receivers rather than the producers of scientific information. This includes not only scientists themselves, but also various other individuals who utilize scientific information in different ways for the benefit of society as a whole.

FREE PDF GRATIS: Studies in History and Philosophy of Science

Procurando o mundo RNA em Marte

sábado, janeiro 28, 2023

In search of the RNA world on Mars

Angel Mojarro, Lin Jin, Jack W. Szostak, James W. Head III, Maria T. Zuber

First published: 10 February 2021

https://doi.org/10.1111/gbi.12433

 


 Image/Imagem: The Scientist

Abstract

Advances in origins of life research and prebiotic chemistry suggest that life as we know it may have emerged from an earlier RNA World. However, it has been difficult to reconcile the conditions used in laboratory experiments with real-world geochemical environments that may have existed on the early Earth and hosted the origin(s) of life. This challenge is due to geologic resurfacing and recycling that have erased the overwhelming majority of the Earth's prebiotic history. We therefore propose that Mars, a planet frozen in time, comprised of many surfaces that have remained relatively unchanged since their formation > 4 Gya, is the best alternative to search for environments consistent with geochemical requirements imposed by the RNA world. In this study, we synthesize in situ and orbital observations of Mars and modeling of its early atmosphere into solutions containing a range of pHs and concentrations of prebiotically relevant metals (Fe2+, Mg2+, and Mn2+) spanning various candidate aqueous environments. We then experimentally determine RNA degradation kinetics due to metal-catalyzed hydrolysis (cleavage) and evaluate whether early Mars could have been permissive toward the accumulation of long-lived RNA polymers. Our results indicate that a Mg2+-rich basalt sourcing metals to a slightly acidic (pH 5.4) environment mediates the slowest rates of RNA cleavage, though geologic evidence and basalt weathering models suggest aquifers on Mars would be near neutral (pH ~ 7). Moreover, the early onset of oxidizing conditions on Mars has major consequences regarding the availability of oxygen-sensitive metals (i.e., Fe2+ and Mn2+) due to increased RNA degradation rates and precipitation. Overall, (a) low pH decreases RNA cleavage at high metal concentrations; (b) acidic to neutral pH environments with Fe2+ or Mn2+ cleave more RNA than Mg2+; and (c) alkaline environments with Mg2+ dramatically cleaves more RNA while precipitates were observed for Fe2+ and Mn2+.

FREE PDF GRATIS: Geobiology

Organização do genoma em 3D: mero acaso, fortuita necessidade ou design inteligente?

quinta-feira, janeiro 12, 2023

3D genome organization

volume
12, Article number: 22106 (2022

Por uma teoria de engenharia da evolução - design inteligente?

terça-feira, janeiro 10, 2023

Towards an engineering theory of evolution

Simeon D. Castle, Claire S. Grierson & Thomas E. Gorochowski 

Nature Communications volume 12, Article number: 3326 (2021)


Image/Imagem

Abstract

Biological technologies are fundamentally unlike any other because biology evolves. Bioengineering therefore requires novel design methodologies with evolution at their core. Knowledge about evolution is currently applied to the design of biosystems ad hoc. Unless we have an engineering theory of evolution, we will neither be able to meet evolution’s potential as an engineering tool, nor understand or limit its unintended consequences for our biological designs. Here, we propose the evotype as a helpful concept for engineering the evolutionary potential of biosystems, or other self-adaptive technologies, potentially beyond the realm of biology.

FREE PDF GRATIS: Nature Communications