O que há de errado com a causalidade evolutiva?
segunda-feira, março 20, 2023
A síntese evolutiva estendida acarreta poder explicativo ampliado?
Does the extended evolutionary synthesis entail extended explanatory power?
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/ImagemAbstract
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
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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
Image/Imagem: eos.org
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
1 The Children’s Museum of Indianapolis, Indianapolis, IN 46208, USA
2 Stiftung Schloss Friedenstein Gotha, 99867 Gotha, Germany
3 Stanford Synchrotron Radiation Light Source, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
4 Department of Biological Sciences, Campus Box 7617, North Carolina State University, Raleigh, NC 27695, USA
5 Paleontology, North Carolina Museum of Natural Sciences, 11 W. Jones St., Raleigh, NC 27601, USA
6 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
Our genomes are highly organized spatially in three-dimensions (3D). In interphase nuclei, the genome is anchored and regulated by various nuclear scaffolds and structures, including the nuclear lamina at the nuclear edge, and nucleoli located more internally within the nucleoplasm. Recently, great effort has been made to understand the intricacies of 3D genome organization and its relevance to genomic and nuclear function. Over the years, many concepts, mathematical models, visual and biochemical methods, and analysis pipelines have been presented to study various aspects of this organization in a multidisciplinary manner, such as is also reflected within this collection.
FREE PDF GRATIS: Scientific Reports
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)
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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