Thought experiments are frequently vague and obscure hypothetical scenarios that are difficult to assess. The paper proposes a simple model of thought experiments. In the first part, I introduce two contemporary frameworks for thought experiment analysis: an experimentalist approach that relies on similarities between real and thought experiment, and a reasonist approach focusing on the answers provided by thought experimenting. Further, I articulate a minimalist approach in which thought experiment is considered strictly as doxastic mechanism based on imagination. I introduce (...) the basic analytical tool that allows us to differentiate an experimental core from an attached argumentation. The last section is reserved for discussion. I address several possible questions concerning adequacy of minimalistic definition and analysis. (shrink)

The paper is a contribution to the debate on the epistemological status of thought experiments. I deal with the epistemological uniqueness of experiments in the sense of their irreducibility to other sources of justification. In particular, I criticize an influential argument for the irreducibility of thought experiments to general arguments. First, I introduce the radical empiricist theory of eliminativism, which considers thought experiments to be rhetorically modified arguments, uninteresting from the epistemological point of view. Second, I present objections to the (...) theory, focusing on the critique of eliminativism by Tamar Szabó Gendler based on the reconstruction of famous Galileo's Pisa experiment. I show that her reconstruction is simplistic and that more elaborate reconstruction is needed for an appropriate assessment of the epistemic power of general argument. I propose such a reconstruction and demonstrate that general version of Pisa experiment is epistemically equal to the particular one. Thus, from an epistemological perspective, Galileo's thought experiment is reducible to a straightforward argument without particular premises. (shrink)

Epistemological optimists about thought experiments hold that imagination could be under certain conditions source of epistemic justification. Their claim is usually based on one of three dominant conceptions about epistemic value of thought experiments. Apriorism states that imagination may serve as unique a priori source of new synthetic knowledge about the actual world. I argue against this view and show that apriorism is either too weak, or too strong or too vague. Psychologism is viable, yet not fully clear conception about (...) new meta-knowledge obtained by thought experimenting. I compare some interpretations of this position and present reasons for favorizing one of them. Conceptualism considers thought experiments as instruments for cleaning our conceptual systems. I argue that this position is in fact not about epistemic value of thought experiments, but about one specific usage of experimental result. (shrink)

The text focuses on Lem’s rejection of the Chinese Room, a prominent challenge to the sufficiency of the Turing test. After outlining Lem’s relationship to the Turing test, it offers an exposition of two of Lem’s thought experiments, the Gramophone and the Jigsaw, whose critique is directly related to the critique of the Chinese Room. The text shows that Lem’s key argument is to point out the computational naivety of the machines that feature in these experiments. The text concludes by (...) presenting some of Lem’s views on the nature of machine consciousness. (shrink)

[Functionalism, Zombies and the Absence of a Mental Dictionary].

Text porovnává přesvědčovací strategie využité ve velmi podobných politicky angažovaných videoklipech The Great Schlep a Přemluv bábu. Ukazuje, že přestože se klip Přemluv bábu od své americké předlohy zásadně neliší v obecné struktuře, deklarovaném cíli či motivické výbavě, v jiných persvazivně významných ohledech se původnímu klipu vzdaluje. Rozdíly jsou patrné zejména v odlišné konstrukci publika, v jiném situování mluvčích a v topickém výběru vyjádřeném jinými stylistickými prostředky.

In the review of 100 myšlenkových experimentů ve filozofii (2013) Jakub Mácha raises several questions concerning our approach to thought experiment analysis. We address all of his remarks; particularly, we answer three questions: Which type of imagination do we use in our definition of thought experiments? How is the cognitive aim of thought experiments related to their cognitive value? Is the analysis of Plato’s Cave proposed in our book appropriate?

Audiozáznam přednášky proslovené ve Filozofické jednotě na Katedře filozofie dne 26. března 2012.V přednášce se pokouším o velmi základní rozlišení tří funkcí, jež mohou myšlenkové experimenty plnit. Nejprve nabízím liberální definici myšlenkového experimentu, podle níž nejde nutně o výjimečné, nereálné, teoreticky zajímavé, bizarní, imaginární scénáře, nýbrž o celkem běžné představování si situace s kognitivním cílem. Snažím se ukázat, že navzdory své šíři je tato definice přiměřeným zachycením všech podstatných vlastností útvarů, jež intuitivně mezi myšlenkové experimenty počítáme. Stručně se poté věnuji (...) prvnímu významu myšlenkových experimentů: imaginární příklady jsou názornou pomůckou při posilování již získaných přesvědčení. Jejich první význam je didaktický. Druhý možný význam myšlenkových experimentů je předmětem vyhraněných diskusí zejména v posledním dvacetiletí: imaginární příklady jsou zdrojem zdůvodnění. Jejich druhý význam je tedy epistemický. Zatímco je však první, didaktický význam zcela nekontroverzní, epistemický význam myšlenkových experimentů je předmětem mnoha odmítnutí. Myšlenkové experimenty jsou tak často odkázány pouze do role názorných pomůcek bez další hodnoty. Snažím se ukázat, že existuje ještě třetí význam myšlenkových experimentů, význam dialektický. Vhodně použitý myšlenkový experiment může v kritické diskusi sloužit jako „přenašeč důkazního břemene”, tj. dokáže vyvolat argumentační tlak na protistranu. Imaginární scénář může za jistých okolností fungovat jako legitimní argument, aniž bychom však nutně museli předpokládat silný epistemický význam myšlenkových experimentů. Myšlenkové experimenty tak mohou být víc než jen líbivé ornamenty, zároveň ale nejsme zavázáni k obhajobě problematické epistemické teze.klíčová slova: myšlenkový experiment, epistemologie, důkazní břemeno. (shrink)

Kuala Lumpur is a diverse city representing many different religions and nationalities. Recent government policy has actively promoted unity and cohesion throughout the city; and the country of Malaysia, with the implementation of a programme called 1Malaysia. In this book, the authors investigate the aims of this programme – predominantly to unify the Malaysian society – and how these objectives resonate in the daily spatial practices of the city’s residents. -/- This book argues that elements of urban infrastructure could work (...) as an essential mediator ‘beyond community’, allowing inclusive social structures to be built, despite cultural and religious tensions existing within the city. It builds on the premise of an empirical study which explores the ways in which different communities use the same spaces, supported through the implementation of a theoretical framework which looks at both Western and Islamic conceptualisations of the notion of community. Through the analysis of Kuala Lumpur, this book contributes towards the creation of more inclusive places in multi-ethnic, multi-cultural and multi-religious communities across the world. (shrink)

Local hidden-variable model of singlet-state correlations discussed in Czachor (Acta Phys Polon A 139:70, 2021a) is shown to be a particular case of an infinite hierarchy of local hidden-variable models based on an infinite hierarchy of calculi. Violation of Bell-type inequalities can be interpreted as a ‘confusion of languages’ problem, a result of mixing different but neighboring levels of the hierarchy. Mixing of non-neighboring levels results in violations beyond the Tsirelson bounds.

History provides us with instances of various societal and economic changes that with a hindsight are interpreted as either indicating progressive or regressive trends. The present paper attempts to define what represents progress and regress by applying psychological constructs to evaluation of the psychosocial changes. Seven principles of progress are applied as criteria for interpreting various historic events. The primary condition for progress is courage to face adversity or, in the cognitive domain, ambiguity, controversy and “unknown”. An overall model of (...) Challenge-Resilience-Resourcefulness is described as the process through which progress can be achieved. (shrink)

A flurry of recent publications have challenged consensus views on the tempo and mode of plastid (chloroplast) evolution in eukaryotes and, more generally, the impact of endosymbiosis in the evolution of the nuclear genome. Endosymbiont‐to‐nucleus gene transfer is an essential component of the transition from endosymbiont to organelle, but the sheer diversity of algal‐derived genes in photosynthetic organisms such as diatoms, as well as the existence of genes of putative plastid ancestry in the nuclear genomes of plastid‐lacking eukaryotes such as (...) ciliates and choanoflagellates, defy simple explanation. Collectively, these papers underscore the power of comparative genomics and, at the same time, reveal how little we know with certainty about the earliest stages of the evolution of photosynthetic eukaryotes. Editor's suggested further reading in BioEssaysEarly steps in plastid evolution: current ideas and controversies AbstractDinoflagellate mitochondrial genomes: stretching the rules of molecular biology Abstract. (shrink)

Clinical Ethics Consultations are an important tool for physicians in solving difficult cases. They are extremely common in North America and to a lesser extent also present in Europe. However, there is little data on this practice in Poland. We present results of a survey of 521 physicians practising in Poland concerning their opinion on CECs and related practices. We analysed the data looking at such issues as CECs’ perceived availability, use of CECs, and perceived usefulness of such support. Physicians (...) in our study generally encounter hard ethics cases, even—surprisingly—those who do not work in hospitals. Most physicians have no CEC access, and those that do still do not employ CECs. However, physicians perceive this form of support as useful—even more so among actual users of CECs. We compared these findings with similar studies from other European countries and the North America. We point out peculiarities of our results as compared to those in other countries, with some possible explanations. We hope the results may encourage regulatory debate on the need to formally introduce CECs into the Polish healthcare system. (shrink)

Bell’s theorem cannot be proved if complementary measurements have to be represented by random variables which cannot be added or multiplied. One such case occurs if their domains are not identical. The case more directly related to the Einstein–Rosen–Podolsky argument occurs if there exists an ‘element of reality’ but nevertheless addition of complementary results is impossible because they are represented by elements from different arithmetics. A naive mixing of arithmetics leads to contradictions at a much more elementary level than the (...) Clauser–Horne–Shimony–Holt inequality. (shrink)

Newtonian physics is based on Newtonian calculus applied to Newtonian dynamics. New paradigms such as ‘modified Newtonian dynamics’ change the dynamics, but do not alter the calculus. However, calculus is dependent on arithmetic, that is the ways we add and multiply numbers. For example, in special relativity we add and subtract velocities by means of addition β1⊕β2=tanh+tanh-1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta _1\oplus \beta _2=\tanh \big +\tanh ^{-1}\big )$$\end{document}, although multiplication β1⊙β2=tanh·tanh-1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} (...) \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta _1\odot \beta _2=\tanh \big \cdot \tanh ^{-1}\big )$$\end{document}, and division β1⊘β2=tanh/tanh-1)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\beta _1\oslash \beta _2=\tanh \big /\tanh ^{-1}\big )$$\end{document} do not seem to appear in the literature. The map fX=tanh-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{\mathbb{X}}=\tanh ^{-1}$$\end{document} defines an isomorphism of the arithmetic in X=\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{X}}=$$\end{document} with the standard one in R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{R}}$$\end{document}. The new arithmetic is projective and non-Diophantine in the sense of Burgin, 1977), while ultrarelativistic velocities are super-large in the sense of Kolmogorov, 1961). Velocity of light plays a role of non-Diophantine infinity. The new arithmetic allows us to define the corresponding derivative and integral, and thus a new calculus which is non-Newtonian in the sense of Grossman and Katz. Treating the above example as a paradigm, we ask what can be said about the set X\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{X}}$$\end{document} of ‘real numbers’, and the isomorphism fX:X→R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{{\mathbb{X}}}:{\mathbb{X}}\rightarrow {\mathbb{R}}$$\end{document}, if we assume the standard form of Newtonian mechanics and general relativity but demand agreement with astrophysical observations. It turns out that the observable accelerated expansion of the Universe can be reconstructed with zero cosmological constant if fX≈0.8sinh/\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f_{\mathbb{X}}\approx 0.8\sinh /$$\end{document}. The resulting non-Newtonian model is exactly equivalent to the standard Newtonian one with ΩΛ=0.7\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega _\Lambda =0.7$$\end{document}, ΩM=0.3\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Omega _M=0.3$$\end{document}. Asymptotically flat rotation curves are obtained if ‘zero’, the neutral element 0X\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$0_{{\mathbb{X}}}$$\end{document} of addition, is nonzero from the point of view of the standard arithmetic of R\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${\mathbb{R}}$$\end{document}. This implies fX-1=0X>0\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f^{-1}_{{\mathbb{X}}}=0_{{\mathbb{X}}}>0$$\end{document}. The opposition Diophantine versus non-Diophantine, or Newtonian versus non-Newtonian, is an arithmetic analogue of Euclidean versus non-Euclidean in geometry. We do not yet know if the proposed generalization ultimately removes any need of dark matter, but it will certainly change estimates of its parameters. Physics of the dark universe seems to be both geometry and arithmetic. (shrink)

Artykuł podejmuje polemikę z obiegowym rozumieniem tolerancji. Autor podkreśla znaczenie podziału na tolerancję jako postawę i na dyskursy o tolerancji. Następnie, w nawiązaniu i częściowo w dyskusji z koncepcją tolerancji zaproponowaną przez Iję Lazari Pawłowską, przedstawione jest rozróżnienie trzech odmian tolerancji, a także rozróżnienie odpowiednich trzech odmian nietolerancji. Rozważane są również niektóre paradoksy związane z tolerancją oraz ze zwalczaniem nietolerancji.

According to UNESCO guidelines, one of the four forms of bioethics committees in medicine are the Hospital Ethics Committees. The purpose of this study was to evaluate how the above guidelines are implemented in real practice. There were 111 hospitals selected out of 176 Polish clinical hospitals and hospitals accredited by Center of Monitoring Quality in Health System. The study was conducted by the survey method. There were 56 hospitals that responded to the survey. The number of HECs members fluctuated (...) between 3 and 16 members, where usually 5 members were part of the board committee. The composition of the HECs for professions other than physicians was diverse and non-standardized. Only 55 % of HECs had a professional set of standards. 98 % of HECs had specific tasks. 62 % of HECs were asked for their expertise, and 55 % prepared <6.88 % of the opinions were related to interpersonal relations between hospital personnel, patients and their families with emphasis on the interactions between superiors and their inferiors or hospital staff and patients and their families. Only 12 % of the opinions were reported by the respondents as related to ethical dilemmas. In conclusion, few Polish hospitals have HECs, and the structure, services and workload are not always adequate. To ensure a reliable operation of HECs requires the development of relevant legislation, standard operating procedures and well trained members. (shrink)

We generalize the notion of analytic/Borel equivalence relations, orbit equivalence relations, and Borel reductions between them to their continuous and quantitative counterparts: analytic/Borel pseudometrics, orbit pseudometrics, and Borel reductions between them. We motivate these concepts on examples and we set some basic general theory. We illustrate the new notion of reduction by showing that the Gromov–Hausdorff distance maintains the same complexity if it is defined on the class of all Polish metric spaces, spaces bounded from below, from above, and from (...) both below and above. Then we show that [Formula: see text] is not reducible to equivalences induced by orbit pseudometrics, generalizing the seminal result of Kechris and Louveau. We answer in negative a question of Ben Yaacov, Doucha, Nies, and Tsankov on whether balls in the Gromov–Hausdorff and Kadets distances are Borel. In appendix, we provide new methods using games showing that the distance-zero classes in certain pseudometrics are Borel, extending the results of Ben Yaacov, Doucha, Nies, and Tsankov. There is a complementary paper of the authors where reductions between the most common pseudometrics from functional analysis and metric geometry are provided. (shrink)

According to The Consensus Gentium Argument from the premise: “Everyone believes that God exists” one can conclude that God does exist. In my paper I analyze two ways of defending the claim that somebody’s belief in God is a prima facie reason to believe. Kelly takes the fact of the commonness of the belief in God as a datum to explain and argues that the best explanation has to indicate the truthfulness of the theistic belief. Trinkaus Zagzebski grounds her defence (...) on rationality of epistemic trust in others. In the paper I argue that the second line of reasoning is more promising and I propose its improved version. (shrink)

ABSTRACT:Microfinance is often assumed to be an ethically progressive industry, but in recent years it has been the target of much ethical criticism. Microfinance institutions have been accused of using exploitative lending techniques and charging usurious interest rates; and critics even question the ability of microfinance to alleviate poverty. This article reviews recent research on the microfinance sector that addresses these ethical issues. We show how this research is relevant to a number of theoretical issues, such as how to define (...) poverty, how to understand exploitation, and how to balance financial and social goals in commercial organizations. We conclude by identifying a critical agenda for future research. (shrink)

We obtain several game characterizations of Baire 1 functions between Polish spaces _X_, _Y_ which extends the recent result of V. Kiss. Then we propose similar characterizations for equi-Bare 1 families of functions. Also, using related ideas, we give game characterizations of Baire measurable and Lebesgue measurable functions.

The production of renewable energy in agricultural biogas plants is being widely criticized because—among other things—most of the feedstock comes from purpose-grown crops like maize. These activities generate competitive pressure to other crops that are used for feeding or food production, worsening their affordability. Unique pretreatment technology that allows substitution of the purpose-grown crops by farming residues was built 6 years ago on a commercial basis in Pěčín under modest funding and without publicity. The design of the concept; financial assessment (...) and moral viewpoint were analyzed based on practical operating data. It showed that the apparatus improves economic, environmental and moral acceptance as well. However, according to the government’s view, public funding for this type of processing was shortened, “because waste materials represent a lower cost”. The impact of such governance was analyzed as well. (shrink)

The Polish equivalents of Research Ethics Committees are Bioethics Committees (BCs). A questionnaire study has been undertaken to determine their situation. The BC is usually comprised of 13 members. Nine of these are doctors and four are non-doctors. In 2006 BCs assessed an average of 27.3 ± 31.7 (range: 0–131) projects of clinical trials and 71.1 ± 139.8 (range: 0–638) projects of other types of medical research. During one BC meeting an average of 10.3 ± 14.7 (range: 0–71) projects of (...) medical research were assessed (2006). The amendment of Polish laws according with Directive 2001/20/EC caused a percentage increase in BCs which assessed less than 20 projects per year (16% vs. 33% or 42% in 2003 vs. 2005 or 2006 respectively, p < 0,05). The results confirm the usefulness of the current practice of creating BCs by medical universities, medical institutes and regional chambers of physicians and dentists but rationalization of the workload for individual BCs is necessary. (shrink)

Referring to basic Weberian notions of rationalization and secularization, I try to find a more accurate sense of the term “secularization”, intending to describe adequately the position of religion in modernity. The result of this query is—or at least should be—a new, original conceptualization of religion as one of finite provinces of meaning within one paramount reality of the life-world, as defined by Alfred Schutz. I proceed by exposing a well known, major oversimplification of the Weberian concept of secularization, very (...) well outlined in Peter Berger’s The sacred canopy, in order to point to the genuine, much more differentiated position of Max Weber in this matter (especially from the period of Foundations of social economic and Economy and society), and, consequently, to return to the roots of Berger’s thought: phenomenological sociology of Alfred Schutz, an attempt to assure the philosophical foundations of Weber’s sociological theory. At a closer glimpse, transformation of religion in the modern process of rationalization does not consist—according to Weber—in eliminating religion and thus depriving society of the religious source of meaning, but in parallel emancipation of many different domains of rationality, including religion itself. Using Schutz’s analysis of the social world as a complex structure of many different final provinces of meaning, I describe religion as such a province and show what does the process of rationalization of this province consist and what it should consist in: a complex, ongoing exchange of cognitive relevances and contents, combined with growing autonomy of many different sub-worlds. Schutz’s theory of symbol, rooted in Edmund Husserl’s description of constitution of complex objects in mono- and polythetic acts of consciousness, moves the analysis to the epistemological level, pointing to a chance of intensifying our cognitive relation to reality through increasing interpenetration of various sub-universes of meaning. (shrink)

Elekes proved that any infinite-fold cover of a σ-finite measure space by a sequence of measurable sets has a subsequence with the same property such that the set of indices of this subsequence has density zero. Applying this theorem he gave a new proof for the random-indestructibility of the density zero ideal. He asked about other variants of this theorem concerning I-almost everywhere infinite-fold covers of Polish spaces where I is a σ-ideal on the space and the set of indices (...) of the required subsequence should be in a fixed ideal ${{\mathcal{J}}}$ on ω. We introduce the notion of the ${{\mathcal{J}}}$ -covering property of a pair ${({\mathcal{A}}, I)}$ where ${{\mathcal{A}}}$ is a σ-algebra on a set X and ${{I \subseteq \mathcal{P}(X)}}$ is an ideal. We present some counterexamples, discuss the category case and the Fubini product of the null ideal ${\mathcal{N}}$ and the meager ideal ${\mathcal{M}}$ . We investigate connections between this property and forcing-indestructibility of ideals. We show that the family of all Borel ideals ${{\mathcal{J}}}$ on ω such that ${\mathcal{M}}$ has the ${{\mathcal{J}}}$ -covering property consists exactly of non weak Q-ideals. We also study the existence of smallest elements, with respect to Katětov–Blass order, in the family of those ideals ${\mathcal{J}}$ on ω such that ${\mathcal{N}}$ or ${\mathcal{M}}$ has the ${\mathcal{J}}$ -covering property. Furthermore, we prove a general result about the cases when the covering property “strongly” fails. (shrink)

The origin and early evolution of animals marks an important event in life's history. This event is historically associated with an important variable in Earth history – oxygen. One view has it that an increase in oceanic oxygen levels at the end of the Neoproterozoic Era (roughly 600 million years ago) allowed animals to become large and leave fossils. How important was oxygen for the process of early animal evolution? New data show that some modern sponges can survive for several (...) weeks at low oxygen levels. Many groups of animals have mechanisms to cope with low oxygen or anoxia, and very often, mitochondria – organelles usually associated with oxygen – are involved in anaerobic energy metabolism in animals. It is a good time to refresh our memory about the anaerobic capacities of mitochondria in modern animals and how that might relate to the ecology of early metazoans. (shrink)