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It has been suggested that evolution of domesticated phenotypes may have evolved as a result of correlated selection responses to reduced fear, a prominent feature in early domestication. To investigate whether domestication changes in social preferences can be attributed to increased tameness, we studied two lines of Red Junglefowl, ancestors of domesticated chickens, bidirectionally selected during 12 generations for high (HF) or low (LF) fear of humans and compared the differences between these lines to those between unselected Red Junglefowl (RJF) and domesticated White Leghorn egg layers (WL). One bird at a time was observed on its own for 12 min in an arena with one adjacent pen behind netting on each side. One of the adjacent pens contained familiar birds, and the other contained unfamiliar birds. Towards the end of the observation period, a sudden stressful stimulus was displayed, and we compared the reactions of the breeds to this as well. Male RJF spent more time close to the unfamiliar birds than WL, and performed more agonistic behaviour, but this was not mirrored in the selected birds. For females, it was WL that performed the most agonistic behaviour. Both LF and WL males showed more non-agonistic social exploration than HF and RJF respectively. Male LF and WL emitted more food calls than HF and RJF respectively. We conclude that several differences between RJF and WL were mirrored in the selection lines, with LF behaving more like domesticated WL. This is in line with the hypothesis that selection for tameness may have driven domestication related changes in social behaviour against conspecifics. [ABSTRACT FROM AUTHOR]

One of the reasons for the physiological and biochemical changes in the body of animals that occur as a result of selection for a defensive reaction toward humans is the activity of the hypothalamic-pituitary-adrenal system. An aggressive response, raising the level of stress in the body, contributes to the disruption of redox balance. However, data on the content of the main natural antioxidant vitamin E in mammals undergoing selection for behavior are limited. This study was designed to determine the content of α-tocopherol in American mink selected to eliminate ("domestic" or tame) or promote (aggressive) defensive reactions toward humans for 22–23 generations. We studied 4 groups (n = 10 in each) of 11-month-old male standard dark brown mink with varying degrees of aggressive (groups –2, –3) or tame (groups +3, +6) behavior. The content of α-tocopherol in the blood serum, liver, kidneys, heart, skeletal muscle, spleen was determined by HPLC. Aggressive mink have lower levels of α-tocopherol in the blood serum and liver, which reflect the status of vitamin E in the body. In most cases, differences were found between mink of the most aggressive and the most "domestic" groups. These results can be associated with features of the neuroendocrine system responsible for aggressive behavior, which affect the processes of metabolism and depletion of α-tocopherol in the body. [ABSTRACT FROM AUTHOR]

We propose that domestication is the result of interspecies cooperative breeding. Considering domestication as an outcome of cooperative breeding can explain how domestication occurs in both plants and animals, encompass cases of domestication that do not involve humans, and shed light on why humans are involved in so many domesticatory relationships. We review the cooperative breeding model of human evolution, which posits that care of human infants by alloparents enabled the evolution of costly human brains and long juvenile development, while selecting for tolerance of strangers. We then explore how human cooperation in the protection and provisioning of young plants and animals can explain the evolution of domestication traits such as changes in development; loss of aggressive, defensive, and bet‐hedging aspects of the phenotype; and increased fertility. We argue that the importance of cooperative breeding to human societies has made humans especially likely to enter into interspecies cooperative breeding relationships. [ABSTRACT FROM AUTHOR]

It has been suggested that evolution of domesticated phenotypes may have evolved as a result of correlated selection responses to reduced fear, a prominent feature in early domestication. To investigate whether domestication changes in social preferences can be attributed to increased tameness, we studied two lines of Red Junglefowl, ancestors of domesticated chickens, bidirectionally selected during 12 generations for high (HF) or low (LF) fear of humans and compared the differences between these lines to those between unselected Red Junglefowl (RJF) and domesticated White Leghorn egg layers (WL). One bird at a time was observed on its own for 12 min in an arena with one adjacent pen behind netting on each side. One of the adjacent pens contained familiar birds, and the other contained unfamiliar birds. Towards the end of the observation period, a sudden stressful stimulus was displayed, and we compared the reactions of the breeds to this as well. Male RJF spent more time close to the unfamiliar birds than WL, and performed more agonistic behaviour, but this was not mirrored in the selected birds. For females, it was WL that performed the most agonistic behaviour. Both LF and WL males showed more non-agonistic social exploration than HF and RJF respectively. Male LF and WL emitted more food calls than HF and RJF respectively. We conclude that several differences between RJF and WL were mirrored in the selection lines, with LF behaving more like domesticated WL. This is in line with the hypothesis that selection for tameness may have driven domestication related changes in social behaviour against conspecifics.

Wolves howl and dogs bark, both are able to produce variants of either vocalization, but we see a distinct difference in usage between wild and domesticate. Other domesticates also show distinct changes to their vocal output: domestic cats retain meows, a distinctly subadult trait in wildcats. Such differences in acoustic output are well‐known, but the causal mechanisms remain little‐studied. Potential links between domestication and vocal output are intriguing for multiple reasons, and offer a unique opportunity to explore a prominent hypothesis in domestication research: the neural crest/domestication syndrome hypothesis. This hypothesis suggests that in the early stages of domestication, selection for tame individuals decreased neural crest cell (NCCs) proliferation and migration, which led to a downregulation of the sympathetic arousal system, and hence reduced fear and reactive aggression. NCCs are a transitory stem cell population crucial during embryonic development that tie to diverse tissue types and organ systems. One of these neural‐crest derived systems is the larynx, the main vocal source in mammals. We argue that this connection between NCCs and the larynx provides a powerful test of the predictions of the neural crest/domestication syndrome hypothesis, discriminating its predictions from those of other current hypotheses concerning domestication. Research highlights: We outline the developmental link between the larynx and the neural crest. This connection provides a powerful test of the predictions of the most prominent hypothesis in domestication research, the neural crest domestication syndrome hypothesis. [ABSTRACT FROM AUTHOR]

Domesticated animals have been developed by selecting desirable traits following the initial unconscious selection stage, and now exhibit phenotypes desired by humans. Tameness is a common behavioural trait found in all domesticated animals. At the same time, these domesticated animals exhibit a variety of morphological, behavioural, and physiological traits that differ from their wild counterparts of their ancestral species. These traits are collectively referred to as domestication syndrome. However, whether this phenomenon exists is debatable. Previously, selective breeding has been used to enhance active tameness, a motivation to interact with humans, in wild heterogeneous stock mice derived from eight wild inbred strains. In the current study, we used tame mice to study how selective breeding for active tameness affects behavioural and morphological traits. A series of behavioural and morphological analyses on mice showed an increased preference for social stimuli and a longer duration of engagement in non‐aggressive behaviour. However, no differences were observed in exploratory or anxiety‐related behaviours. Similarly, selection for tameness did not affect ultrasonic vocalisations in mice, and no changes were observed in known morphological traits associated with domestication syndrome. These results suggest that there may be a link between active tameness and sociability and provide insights into the relationship between tameness and other behaviours in the context of domestication. [ABSTRACT FROM AUTHOR]

The way genes contribute to behavior is complicated. Although there are some single genes with large contributions, most behavioral differences are due to small effects from many interacting genes. This makes it hard to identify the genes that cause behavioral differences. Mutagenesis screens in model organisms, selective breeding experiments in animals, comparisons between related populations with different behaviors, and genome-wide association studies in humans are promising and complementary approaches to understanding the heritable aspects of complex behaviors. To connect genes to behaviors requires measuring behavioral differences, locating correlated genetic changes, determining when, where, and how these candidate genes act, and designing causative confirmatory experiments. This area of research has implications from basic discovery science to human mental health.

We broaden the framework of metric abstract elementary classes (mAECs) in several essential ways, chiefly by allowing the metric to take values in a well-behaved quantale. As a proof of concept we show that the result of Boney and Zambrano (Around the set-theoretical consistency of d-tameness of metric abstract elementary classes, arXiv:1508.05529, 2015) on (metric) tameness under a large cardinal assumption holds in this more general context. We briefly consider a further generalization to partial metric spaces, and hint at connections to classes of fuzzy structures, and structures on sheaves. [ABSTRACT FROM AUTHOR]

Although there is some evidence to suggest that there is a link between behavior and immune parameters in animals, this issue is still not well understood. In particular, there is a lack of understanding of how specific behaviors affect the size of immune cells. To address this issue, we investigated the relationship between behavior and the morphometric parameters of lymphocytes in American mink (Neogale vison) that have been selectively bred for aggression and tameness toward humans at the Institute of Cytology and Genetics in Novosibirsk, Russia, for 37 years. Minks with high ("-3") and medium ("-2") aggressiveness, moderate ("+ 3") and high tameness ("+ 6"), as well as those not affected by special behavior selection, were compared with each other. We found that aggressive and tame mink significantly differed in lymphocyte size, cytoplasm content and nucleus to cell ratio (NCR). The lymphocytes of tame mink were characterized by larger size, increased cytoplasm content and lower NCR compared to those of aggressive mink and unselected mink. Among the studied parameters, the largest differences were found in the size of lymphocytes between "+ 3" and unselected minks (p = 0.000018) and in the cytoplasm content between "+ 6" and unselected minks (p = 0.000039). Minks with similar behavior ("-3" and "-2", "+ 3" and "+ 6") showed no significant differences. Our data, combined with the strong correlation reported by other researchers between morphological characteristics of lymphocytes and cytokine levels indicates that selection for specific behaviors may lead to a rebalancing in the immune system. • There are differences between mink behavioral lines in morphometric parameters of lymphocytes. • The tame mink have significantly larger lymphocytes as compared to aggressive mink. • Selection for tame and aggressive behavior toward to humans leads to a rebalancing of the immune system. [ABSTRACT FROM AUTHOR]

Abstract The neural crest hypothesis posits that selection for tameness resulted in mild alterations to neural crest cells during embryonic development, which directly or indirectly caused the appearance of traits associated with the “domestication syndrome” (DS). Although representing an appealing unitary explanation for the generation of domestic phenotypes, support for this hypothesis from morphological data and for the validity of the DS remains a topic of debate. This study used the frameworks of morphological integration and modularity to assess patterns that concern the embryonic origin of the skull and issues around the neural crest hypothesis. Geometric morphometric landmarks were used to quantify cranial trait interactions between six pairs of wild and domestic mammals, comprising representatives that express between five and 17 of the traits included in the DS, and examples from each of the pathways by which animals entered into relationships with humans. We predicted the presence of neural crest vs mesoderm modular structure to the cranium, and that elements in the neural crest module would show lower magnitudes of integration and higher disparity in domestic forms compared to wild forms. Our findings support modular structuring based on tissue origin (neural crest, mesoderm) modules, along with low module integration magnitudes for neural crest cell derived cranial elements, suggesting differential capacity for evolutionary response among those elements. Covariation between the neural crest and mesoderm modules accounted for major components of shape variation for most domestic/wild pairs. Contra to our predictions, however, we find domesticates share similar integration magnitudes to their wild progenitors, indicating that higher disparity in domesticates is not associated with magnitude changes to integration among either neural crest or mesoderm derived elements. Differences in integration magnitude among neural crest and mesoderm elements across species suggest that developmental evolution preserves a framework that promotes flexibility under the selection regimes of domestication.

The program-over-monoid model of computation originates with Barrington’s proof that the model captures the complexity class NC¹ . Here we make progress in understanding the subtleties of the model. First, we identify a new tameness condition on a class of monoids that entails a natural characterization of the regular languages recognizable by programs over monoids from the class. Second, we prove that the class known as DA satisfies tameness and hence that the regular languages recognized by programs over monoids in DA are precisely those recognizable in the classical sense by morphisms from QDA. Third, we show by contrast that the well studied class of monoids called J is not tame. Finally, we exhibit a program-length-based hierarchy within the class of languages recognized by programs over monoids from DA. [ABSTRACT FROM AUTHOR]

We show that graph map with zero topological entropy is Li-Yorke chaotic if and only if it has an NS-pair (a pair of non-separable points containing in a same solenoidal \omega-limit set), and a non-diagonal pair is an NS-pair if and only if it is an IN-pair if and only if it is an IT-pair. This completes characterization of zero topological sequence entropy for graph maps. [ABSTRACT FROM AUTHOR]

The neural crest hypothesis posits that selection for tameness resulted in mild alterations to neural crest cells during embryonic development, which directly or indirectly caused the appearance of traits associated with the "domestication syndrome" (DS). Although representing an appealing unitary explanation for the generation of domestic phenotypes, support for this hypothesis from morphological data and for the validity of the DS remains a topic of debate. This study used the frameworks of morphological integration and modularity to assess patterns that concern the embryonic origin of the skull and issues around the neural crest hypothesis. Geometric morphometric landmarks were used to quantify cranial trait interactions between six pairs of wild and domestic mammals, comprising representatives that express between five and 17 of the traits included in the DS, and examples from each of the pathways by which animals entered into relationships with humans. We predicted the presence of neural crest vs mesoderm modular structure to the cranium, and that elements in the neural crest module would show lower magnitudes of integration and higher disparity in domestic forms compared to wild forms. Our findings support modular structuring based on tissue origin (neural crest, mesoderm) modules, along with low module integration magnitudes for neural crest cell derived cranial elements, suggesting differential capacity for evolutionary response among those elements. Covariation between the neural crest and mesoderm modules accounted for major components of shape variation for most domestic/wild pairs. Contra to our predictions, however, we find domesticates share similar integration magnitudes to their wild progenitors, indicating that higher disparity in domesticates is not associated with magnitude changes to integration among either neural crest or mesoderm derived elements. Differences in integration magnitude among neural crest and mesoderm elements across species suggest that developmental evolution preserves a framework that promotes flexibility under the selection regimes of domestication. [ABSTRACT FROM AUTHOR]

We provide comprehensive, level-by-level characterizations of large cardinals, in the range from weakly compact to strongly compact, by closure properties of powerful images of accessible functors. In the process, we show that these properties are also equivalent to various forms of tameness for abstract elementary classes. This systematizes and extends results of [W. Boney and S. Unger, Large cardinal axioms from tameness in AECs, Proc. Amer. Math. Soc.145(10) (2017) 4517–4532; A. Brooke-Taylor and J. Rosický, Accessible images revisited, Proc. AMS145(3) (2016) 1317–1327; M. Lieberman, A category-theoretic characterization of almost measurable cardinals (Submitted, 2018), http://arxiv.org/abs/1809.06963; M. Lieberman and J. Rosický, Classification theory for accessible categories. J. Symbolic Logic81(1) (2016) 1647–1648]. [ABSTRACT FROM AUTHOR]

Tameness is a major element of animal domestication and involves two components: motivation to approach humans (active tameness) and reluctance to avoid humans (passive tameness). To understand the behavioral and genetic mechanisms of active tameness in mice, we had previously conducted selective breeding for long durations of contact and heading toward human hands in an active tameness test using a wild‐derived heterogeneous stock. Although the study showed a significant increase in contacting and heading with the 12th generation of breeding, the effect on other behavioral indices related to tameness and change of gene expression levels underlying selective breeding was unclear. Here, we analyzed nine tameness‐related traits at a later stage of selective breeding and analyzed how gene expression levels were changed by the selective breeding. We found that five traits, including contacting and heading, showed behavioral change in the selective groups comparing to the control through the generations. Furthermore, we conducted cluster analyses to evaluate the relationships among the nine traits and found that contacting and heading combined in an independent cluster in the selected groups, but not in the control groups. RNA‐Seq of hippocampal tissue revealed differential expression of 136 genes between the selection and control groups, while the pathway analysis identified the networks associated with these genes. These results suggest that active tameness was hidden in the control groups but became apparent in the selected populations by selective breeding, potentially driven by changes in gene expression networks. [ABSTRACT FROM AUTHOR]

Early animal domestication may have been driven by selection on tameness. Selection on only tameness can bring about correlated selection responses in other traits, not intentionally selected upon, which may be one cause of the domesticated phenotype. We predicted that genetically reduced fear towards humans in Red Junglefowl, ancestors of domesticated chickens, would be correlated to other traits included in the domesticated phenotype. Fear level was determined by a standardised behaviour test, where the reaction towards an approaching human was recorded. We first selected birds for eight generations for either high or low fear levels in this test, to create two divergent selection lines. An F3 intercross, with birds from the eighth generation as parentals, was generated to study correlations between fear‐of‐human scores and other unselected phenotypes, possibly caused by pleiotropy or linkage. Low fear‐of‐human scores were associated with higher body weight and growth rates, and with increased activity in an open field test, indicating less general fearfulness. In females, low fear‐of‐human scores were also associated with more efficient fear habituation and in males with an increased tendency to emit food calls in a mirror test, indicating increased social dominance. Low fear‐of‐human scores were also associated with smaller brain relative to body weight, and with larger cerebrum relative to total brain weight in females. All these effects are in line with the changes observed in domesticated chickens compared to their ancestors, and we conclude that tameness may have been a driving factor underlying some aspects of the domesticated phenotype. [ABSTRACT FROM AUTHOR]

Brain size reduction is a common trait in domesticated species when compared to wild conspecifics. This reduction can happen through changes in individual brain regions as a response to selection on specific behaviours. We selected red junglefowl for 10 generations for diverging levels of fear towards humans and measured brain size and composition as well as habituation learning and conditioned place preference learning in young chicks. Brain size relative to body size as well as brainstem region size relative to whole brain size were significantly smaller in chicks selected for low fear of humans compared to chicks selected for high fear of humans. However, when including allometric effects in the model, these differences disappear but a tendency towards larger cerebra in low-fear chickens remains. Low-fear line chicks habituated more effectively to a fearful stimulus with prior experience of that same stimulus, whereas high-fear line chicks with previous experience of the stimulus had a response similar to naive chicks. The phenotypical changes are in line with previously described effects of domestication.

We introduce the notion of a w-good λ -frame which is a weakening of Shelah's notion of a good λ -frame. Existence of a w-good λ -frame implies existence of a model of size λ + + . Tameness and amalgamation imply extension of a w-good λ -frame to larger models. As an application we show: Theorem 0.1. Suppose 2 λ < 2 λ + < 2 λ + + and 2 λ + > λ + + . If I (K , λ) = I (K , λ +) = 1 ≤ I (K , λ + +) < 2 λ + + and K is (λ , λ +) -tame, then K λ + + + ≠ ∅ . The proof presented clarifies some of the details of the main theorem of Shelah (Isr J Math 126:29–128, 2001) and avoids using the heavy set-theoretic machinery of Shelah (Classification theory for abstract elementary classes, College Publications, Charleston, 2009 [§VII]) by replacing it with tameness. [ABSTRACT FROM AUTHOR]

Abstract Background Japanese indigenous chicken breeds are often used to improve meat quality rather than broilers in the Jidori industry. There are sometimes severe crowding accidents caused by many birds frightened by environmental stimuli. To prevent the economic loss, the chickens need to be more gentle, tame, and imperturbable. Methods In this study, a new handling test for tameness in adult chickens in individual cages was performed with 100 birds from each sex of Shamo, Rhode Island Red, Nagoya, Australorp, and Ukokkei, as well as 10 hens of F1 hybrid between Shamo and Rhode Island Red, to measure both active and passive tameness. We counted the number heading toward human hands (heading) and retreating in other directions (avoiding) in both active and passive tameness phases, as well as the number of steps taken (step) during the handling test. Results Male chickens exhibited higher avoidance behavior than females. Nagoya females displayed the lowest level of avoidance behavior, which implies passive tameness. In terms of active tameness, a variety of phenotypes can be obtained in different combinations of breed and sex. These results suggested the handling test will be good method for rapid screening of individual differences in tameness. In addition, there were heterosis effects on avoidance and locomotive behaviors. Since F1 is often used in the Jidori industry, the breeders should be tested not only for meat production but also for tameness. Conclusions In the future, combining both the behavioral screening and the population genomics will establish typical evidence about mechanisms of tameness and domestication in animals.

"Self‐domestication" has been invoked to understand important aspects of human evolution, integrating physiological, behavioral, and morphological information in a novel way. It proposes that selection for reduced aggression on animals undergoing domestication provides a model for selection favoring prosocial behaviors in humans and for a set of seemingly independent features, which arose as a result of developmental correlation. We review the history of the idea and examine patterns of domestication. A lack of empirical studies on evolutionary rates and variation thwarts meaningful comparison with domestication. The neural crest hypothesis for domestication has great explanatory power but it is difficult to test. We suggest a scenario in which the morphological byproducts of domestication can act as an honest signal of reduced xenophobia. Future studies should test if alternative explanations for the features deemed to result from self‐domestication are mutually exclusive and generate data to test predictions of these hypotheses. [ABSTRACT FROM AUTHOR]

Let S be a Noetherian scheme and ƒ : X → S a proper morphism. By SGA 4 XIV, for any constructible sheaf F of Z/nZ-modules on X, the sheaves of Z/nZ-modules Ri ƒ*F obtained by direct image (for the étale topology) are themselves constructible, that is, there is a stratification S of S on whose strata these sheaves are locally constant constructible. After previous work of N. Katz and G. Laumon, or L. Illusie, on the special case in which S is generically of characteristic zero or the sheaves F are constant (with invertible torsion on S), here we study the dependency of S on F. We show that a natural ‘uniform’ tameness and constructibility condition satisfied by constant sheaves, which was introduced by O. Gabber, is stable under the functors Ri ƒ*. If f is not proper, this result still holds assuming tameness at infinity, relative to S. We also prove the existence of uniform bounds on Betti numbers, in particular for the stalks of the sheaves Ri ƒ*Fl, where L ranges through all prime numbers invertible on S. [ABSTRACT FROM AUTHOR]

We give a necessary condition for a subset of R³ to be the set of critical points of some smooth function. In particular we obtain that for example neither the Whitehead continuum nor the p-adic solenoid are such critical sets. [ABSTRACT FROM AUTHOR]

We initiate a systematic investigation of the abstract elementary classes that have amalgamation, satisfy tameness (a locality property for orbital types), and are stable (in terms of the number of orbital types) in some cardinal. Assuming the singular cardinal hypothesis (SCH), we prove a full characterization of the (high-enough) stability cardinals, and connect the stability spectrum with the behavior of saturated models. We deduce (in ZFC) that if a class is stable on a tail of cardinals, then it has no long splitting chains (the converse is known). This indicates that there is a clear notion of superstability in this framework. We also present an application to homogeneous model theory: for D a homogeneous diagram in a first-order theory T , if D is both stable in | T | and categorical in | T | then D is stable in all λ ≥ | T |. [ABSTRACT FROM AUTHOR]

Shelah has provided sufficient conditions for an ${\Bbb L}_{\omega _1 ,\omega } $ -sentence ψ to have arbitrarily large models and for a Morley-like theorem to hold of ψ. These conditions involve structural and set-theoretic assumptions on all the ${\aleph _n}$ 's. Using tools of Boney, Shelah, and the second author, we give assumptions on ${\aleph _0}$ and ${\aleph _1}$ which suffice when ψ is restricted to be universal: Theorem. Assume ${2^{{\aleph _0}}}. Let ψ be a universal ${\Bbb L}_{\omega _1 ,\omega } $ -sentence. (1) If ψ is categorical in ${\aleph _0}$ and $1 \leqslant {\Bbb L}\left({\psi ,\aleph _1 } \right) , then ψ has arbitrarily large models and categoricity of ψ in some uncountable cardinal implies categoricity of ψ in all uncountable cardinals. (2) If ψ is categorical in ${\aleph _1}$ , then ψ is categorical in all uncountable cardinals. The theorem generalizes to the framework of ${\Bbb L}_{\omega _1 ,\omega } $ -definable tame abstract elementary classes with primes. [ABSTRACT FROM AUTHOR]

Let T be a consistent o-minimal theory extending the theory of densely ordered groups and let T ′ be a consistent theory. Then there is a complete theory T ⁎ extending T such that T is an open core of T ⁎ , but every model of T ⁎ interprets a model of T ′ . If T ′ is NIP, T ⁎ can be chosen to be NIP as well. From this we deduce the existence of an NIP expansion of the real field that has no distal expansion. [ABSTRACT FROM AUTHOR]

Similar phenotypic changes occur across many species as a result of domestication, e.g. in pigmentation and snout size. Experimental studies of domestication have concentrated on intense and directed selection regimes, while conditions that approximate the commensal and indirect interactions with humans have not been explored. We examine long-term data on a free-living population of wild house mice that have been indirectly selected for tameness by regular exposure to humans. In the course of a decade, this mouse population exhibited significantly increased occurrence of white patches of fur and decreased head length. These phenotypic changes fit to the predictions of the ‘domestication syndrome'.

In the context of abstract elementary classes (AECs) with a monster model, several possible definitions of superstability have appeared in the literature. Among them are no long splitting chains, uniqueness of limit models, and solvability. Under the assumption that the class is tame and stable, we show that (asymptotically) no long splitting chains implies solvability and uniqueness of limit models implies no long splitting chains. Using known implications, we can then conclude that all the previously-mentioned definitions (and more) are equivalent:Corollary.LetKbe a tame AEC with a monster model. Assume thatKis stable in a proper class of cardinals. The following are equivalent:(1)For all high-enough λ,Khas no long splitting chains.(2)For all high-enough λ, there exists a good λ-frame on a skeleton ofKλ.(3)For all high-enough λ,Khas a unique limit model of cardinality λ.(4)For all high-enough λ,Khas a superlimit model of cardinality λ.(5)For all high-enough λ, the union of any increasing chain of λ-saturated models is λ-saturated.(6)There exists μ such that for all high-enough λ,Kis (λ,μ) -solvable.This gives evidence that there is a clear notion of superstability in the framework of tame AECs with a monster model. [ABSTRACT FROM AUTHOR]

We develop a notion of forking for Galois-types in the context of Abstract Elementary Classes (AECs). Under the hypotheses that an AEC K is tame, type-short, and failure of an order-property, we consider Definition 1 Let M 0 ≺ N be models from K and A be a set. We say that the Galois-type of A over N does not fork over M 0 , written A ⫝ M 0 N , iff for all small a ∈ A and all small N − ≺ N , we have that Galois-type of a over N − is realized in M 0 . Assuming property ( E ) (Existence and Extension, see Definition 3.3) we show that this non-forking is a well behaved notion of independence, in particular satisfies symmetry and uniqueness and has a corresponding U-rank. We find conditions for a universal local character, in particular derive superstability-like property from little more than categoricity in a “big cardinal”. Finally, we show that under large cardinal axioms the proofs are simpler and the non-forking is more powerful. In [10] , it is established that, if this notion is an independence notion, then it is the only one. [ABSTRACT FROM AUTHOR]

We study when a union of saturated models is saturated in the framework of tame abstract elementary classes (AECs) with amalgamation. We prove: Theorem 0.1. If K is a tame AEC with amalgamation satisfying a natural definition of superstability (which follows from categoricity in a high-enough cardinal), then for all high-enough $$\lambda {:}$$ Our proofs use independence calculus and a generalization of averages to this non first-order context. [ABSTRACT FROM AUTHOR]

This paper is part of a program initiated by Saharon Shelah to extend the model theory of first order logic to the non-elementary setting of abstract elementary classes (AECs). An abstract elementary class is a semantic generalization of the class of models of a complete first order theory with the elementary substructure relation. We examine the symmetry property of splitting (previously isolated by the first author) in AECs with amalgamation that satisfy a local definition of superstability. The key results are a downward transfer of symmetry and a deduction of symmetry from failure of the order property. These results are then used to prove several structural properties in categorical AECs, improving classical results of Shelah who focused on the special case of categoricity in a successor cardinal. We also study the interaction of symmetry with tameness, a locality property for Galois (orbital) types. We show that superstability and tameness together imply symmetry. This sharpens previous work of Boney and the second author. [ABSTRACT FROM AUTHOR]

Islands play an important conservation role due to high rates of speciation as well as providing a predator-free refuge environment for species that are vulnerable to terrestrial predation on the mainland. Many animals show marked 'island tameness' on predator-free islands, reducing costly escape responses in the absence of predation threat. Island tameness also translates to altered responses toward humans, making many island species attractive for wildlife tourism. We explored temporal and spatial differences in behavioral responses in the Rottnest Island quokka Setonix brachyurus. This marsupial is an excellent species to test for the effects of ecotourism, as well as of being conservation significance ( IUCN-listed as vulnerable). Comparing escape responses for n = 339 individuals in high tourism and low tourism seasons, quokkas at tourism sites allowed a person to approach closer before moving away compared with non-tourisms sites, and two-thirds of individuals around tourism sites allowed a person to approach within 1 m (compared with 14% of individuals at non-tourism sites). For n = 67 ad hoc interactions with tourists, quokkas would only move away from an interaction with a tourist when the tourist group was noisy or there was an attempt to touch the animal. Time budgets ( n = 379 individuals) showed that quokkas spent more time in group behavior and locomotion, but less in vigilance and feeding for tourism sites compared with non-tourism sites. Understanding the impact of ecotourism on animal behavior will help to frame conservation management actions to ensure persistence of threatened wildlife species. We propose two models describing animal responses toward ecotourism: spatial separation according to animal temperament or temporal adjustment due to learned habituation. These models are not mutually exclusive and we suggest that both spatial separation and habitation are likely evident for Rottnest quokkas. We discuss the implications of these results for protection of animals on the island as well as for species conservation. [ABSTRACT FROM AUTHOR]

In the setting of abstract elementary classes (AECs) with amalgamation, Shelah has proven a downward categoricity transfer from categoricity in a successor and Grossberg and VanDieren have established an upward transfer assuming in addition a locality property for Galois types that they called tameness. We further investigate categoricity transfers in tame AECs. We use orthogonality calculus to prove a downward transfer from categoricity in a successor in AECs that have a good frame (a forking-like notion for types of singletons) on an interval of cardinals: Theorem 0.1 Let K be an AEC and let LS ( K ) ≤ λ < θ be cardinals. If K has a type-full good [ λ , θ ] -frame and K is categorical in both λ and θ + , then K is categorical in all μ ∈ [ λ , θ ] . We deduce improvements on the threshold of several categoricity transfers that do not mention frames. For example, the threshold in Shelah's transfer can be improved from ℶ ℶ ( 2 LS ( K ) ) + to ℶ ( 2 LS ( K ) ) + assuming that the AEC is LS ( K ) -tame. The successor hypothesis can also be removed from Shelah's result by assuming in addition either that the AEC has primes over sets of the form M ∪ { a } or (using an unpublished claim of Shelah) that the weak generalized continuum hypothesis holds. [ABSTRACT FROM AUTHOR]

The problem of the origin of domestic animals and plants, and the means by which they were produced along human history, were of deep interest to Charles Darwin who considered domestic breeding ‘one grand experiment’ in evolution. In frst place, he elaborated an analogy between artifcial selection, by which breeders obtained desired characters in domestic species, and natural selection, the powerful force driving evolution in nature. At the same time, Darwin distinguished two processes within artifcial selection: methodical and unconscious selection. He attached great importance to the latter since it could produce gradual unexpected changes in association with those characters that were consciously selected for. Although the analogy natural/artifcial selection was initially controversial, it proved to be extremely useful in establishing the reality of natural selection as a key evolutionary factor. Nevertheless, the mechanisms involved in the process of domestication were largely unknown and posed intriguing problems such as the recurrent morphological, physiological, and behavioural similarities that appeared in widely different domestic animals. A distinguished Russian geneticist, Dmitry K. Belyaev, proposed that domestication was ruled by a process of ‘destabilizing selection’ affecting mechanisms of ontogenetic neuroendocrine control, either directly or indirectly in response to the appearance of a factor of stress. He also suggested that the key factor of domestication producing striking similar results in many species is selection for tameness. Thus, in 1959 he set up a long-term experiment of domestication of wild foxes (Vulpes vulpes) in which individuals were exclusively selected for tameness. Today, almost 50 generations later, near 100% of the experimental population actively seeks contact with humans. They exhibit a typical dog-like behaviour, which has been shown to be directly related to neuroendocrine ontogenetic modifcations. Typical dog-like morphological, physiological and reproductive characteristics also appeared in the domesticated foxes. In this essay I review Darwin’s ideas on domestication and then focus on Belyaev’s still ongoing experiment and the consequences of its results for the theory of domestication and evolution.El problema del origen de los animales y plantas domésticos, y los medios por los cuales fueron producidos a lo largo de la historia humana, eran de profundo interés para Charles Darwin que consideraba la domesticación como ‘one grand experiment’ en evolución. En primer lugar, elaboró una analogía entre la selección artifcial, por la cual los criadores obtenían caracteres deseados en especies domésticas, y la selección natural, la poderosa fuerza conductora de la evolución en la naturaleza. Al mismo tiempo, Darwin distinguió dos procesos dentro de la selección artifcial: selección metódica y selección inconsciente. Adjudicó gran importancia a esta última ya que podía producir cambios graduales inesperados asociados a aquellos caracteres conscientemente seleccionados. Aunque la analogía selección natural/selección artifcial fue inicialmente controvertida, demostró ser extremadamente útil para establecer la realidad de la selección natural como el factor clave de la evolución. De todos modos, los mecanismos involucrados en el proceso de domesticación eran ampliamente desconocidos y planteaban problemas intrigantes como las causas subyacentes a las recurrentes similaridades morfológicas, fsiológicas y comportamentales que aparecían en distintas especies de animales domésticos. Un distinguido genetista ruso, Dmitry K. Belyaev, propuso que la domesticación era regida por un proceso de ‘selección desestabilizadora’ que afecta los mecanismos de control neuroendocrino de la ontogénesis directa o indirectamente en respuesta a la aparición de un factor de stress. También sugirió que el factor clave de la domesticación, que producía sorprendentes resultados similares en muchas species, es la selección para mansedumbre (tameness). Entonces, en 1959, diseñó un experimento a largo plazo de domesticación de zorros silvestres (Vulpes vulpes), en el cual los zorros eran exclusivamente seleccionados para mansedumbre. Actualmente, casi 50 generaciones después, cerca del 100% de la población experimental busca contacto activo con los humanos exhibiendo un comportamiento típicamente perruno que ha sido directamente relacionado a modifcaciones neuroendocrinas ontogenéticas. Los zorros domesticados tambien exhiben características morfológicas, fsiológicas y reproductivas típicamente perrunas. En este ensayo, paso revista a las ideas de Darwin sobre domesticación y luego me enfoco en el experimento, aún en marcha, de Belyaev y las consecuencias de sus resultados para la teoría de la domesticación y la evolución.

We show that ℶ (2 LS (K)) + is the lower bound to the Hanf numbers for the length of the order property and for stability in stable abstract elementary classes (AECs). Our examples satisfy the joint embedding property, no maximal model, and (< ℵ 0) -tameness but not necessarily the amalgamation property. We also define variations on the order and syntactic order properties insofar as it allows the index set to be linearly ordered rather than well-ordered. Combining with Shelah's stability theorem, we deduce that our examples can have the order property up to any μ < ℶ (2 LS (K)) + . Boney conjectured that the joint embedding property is needed for two type-counting lemmas. We solved the conjecture by showing it is independent of ZFC. [ABSTRACT FROM AUTHOR]

We study general methods to build forking-like notions in the framework of tame abstract elementary classes (AECs) with amalgamation. We show that whenever such classes are categorical in a high-enough cardinal, they admit a good frame: a forking-like notion for types of singleton elements. Theorem 0.1 Superstability from categoricity Let K be a ( < κ ) -tame AEC with amalgamation. If κ = ℶ κ > LS ( K ) and K is categorical in a λ > κ , then: • K is stable in any cardinal μ with μ ≥ κ . • K is categorical in κ. • There is a type-full good λ-frame with underlying class K λ . Under more locality conditions, we prove that the frame extends to a global independence notion (for types of arbitrary length). Theorem 0.2 A global independence notion from categoricity Let K be a densely type-local, fully tame and type short AEC with amalgamation. If K is categorical in unboundedly many cardinals, then there exists λ ≥ LS ( K ) such that K ≥ λ admits a global independence relation with the properties of forking in a superstable first-order theory. As an application, we deduce (modulo an unproven claim of Shelah) that Shelah's eventual categoricity conjecture for AECs (without assuming categoricity in a successor cardinal) follows from the weak generalized continuum hypothesis and a large cardinal axiom. Corollary 0.3 Assume 2 λ < 2 λ + for all cardinals λ, as well as an unpublished claim of Shelah. If there exists a proper class of strongly compact cardinals, then any AEC categorical in some high-enough cardinal is categorical in all high-enough cardinals. [ABSTRACT FROM AUTHOR]

Domestication of wild animals alters the aggression towards humans, brain monoamines and coat pigmentation. Our aim is the interplay between aggression, brain monoamines and depigmentation. The Hedlund white mutation in the American mink is an extreme case of depigmentation observed in domesticated animals. The aggressive (−2.06 ± 0.03) and tame (+3.5 ± 0.1) populations of wild-type dark brown color (standard) minks were bred during 17 successive generations for aggressive or tame reaction towards humans, respectively. The Hedlund mutation was transferred to the aggressive and tame backgrounds to generate aggressive (−1.2 ± 0.1) and tame (+3.0 ± 0.2) Hedlund minks. Four groups of 10 males with equal expression of aggressive (−2) or tame (+5) behavior, standard or with the Hedlund mutation, were selected to study biogenic amines in the brain. Decreased levels of noradrenaline in the hypothalamus, but increased concentrations of the serotonin metabolite, 5-hydroxyindoleacetic acid and dopamine metabolite, homovanillic acid, in the striatum were measured in the tame compared with the aggressive standard minks. The Hedlund mutation increased noradrenaline level in the hypothalamus and substantia nigra, serotonin level in the substantia nigra and striatum and decreased dopamine concentration in the hypothalamus and striatum. Significant interaction effects were found between the Hedlund mutation and aggressive behavior on serotonin metabolism in the substantia nigra ( P < 0.001), dopamine level in the midbrain ( P < 0.01) and its metabolism in the striatum ( P < 0.05). These results provide the first experimental evidence of the interplay between aggression, brain monoamines and the Hedlund mutation in the American minks. [ABSTRACT FROM AUTHOR]

We prove that any tame abstract elementary class categorical in a suitable cardinal has an eventually global good frame: a forking-like notion defined on all types of single elements. This gives the first known general construction of a good frame in ZFC. We show that we already obtain a well-behaved independence relation assuming only a superstability-like hypothesis instead of categoricity. These methods are applied to obtain an upward stability transfer theorem from categoricity and tameness, as well as new conditions for uniqueness of limit models. [ABSTRACT FROM PUBLISHER]

We show that a number of results on abstract elementary classes (AECs) hold in accessible categories with concrete directed colimits. In particular, we prove a generalization of a recent result of Boney on tameness under a large cardinal assumption. We also show that such categories support a robust version of the Ehrenfeucht–Mostowski construction. This analysis has the added benefit of producing a purely language-free characterization of AECs, and highlights the precise role played by the coherence axiom. [ABSTRACT FROM PUBLISHER]

We combine two approaches to the study of classification theory of AECs: (1) that of Shelah: studying non-forking frames without assuming the amalgamation property but assuming the existence of uniqueness triples and (2) that of Grossberg and VanDieren [6] : (studying non-splitting) assuming the amalgamation property and tameness. In [7] we derive a good non-forking λ + -frame from a semi-good non-forking λ -frame. But the classes K λ + and ⪯ ↾ K λ + are replaced: K λ + is restricted to the saturated models and the partial order ⪯ ↾ K λ + is restricted to the partial order ⪯ λ + NF . Here, we avoid the restriction of the partial order ⪯ ↾ K λ + , assuming that every saturated model (in λ + over λ ) is an amalgamation base and ( λ , λ + ) -tameness for non-forking types over saturated models (in addition to the hypotheses of [7] ): Theorem 7.15 states that M ⪯ M + if and only if M ⪯ λ + NF M + , provided that M and M + are saturated models. We present sufficient conditions for three good non-forking λ + -frames: one relates to all the models of cardinality λ + and the two others relate to the saturated models only. By an ‘unproven claim’ of Shelah, if we can repeat this procedure ω times, namely, ‘derive’ good non-forking λ + n frame for each n < ω then the categoricity conjecture holds. In [14] , Vasey applies Theorem 7.8 , proving the categoricity conjecture under the above ‘unproven claim’ of Shelah. In [10] , we apply Theorem 7.15 , proving the existence of primeness triples. [ABSTRACT FROM AUTHOR]

O artigo defende a idéia de que a questão da gênese social de técnicas deve ser abordada levando-se em conta prioritariamente aquilo que se chama, por convenção, de "escolhas técnicas", invertendo o procedimento habitual para estudá-las. Ao invés de explicações tautológicas que visam a esclarecer as vantagens adaptativas que tornariam necessárias a emergência de uma técnica, questiona-se, aqui, as determinações negativas da escolha: por que tal técnica não apareceu em tal contexto particular que a tornaria possível? Toda técnica resumindo-se a uma relação entre o homem e a matéria viva (nela compreendido ele mesmo) ou inorgânica, esta relação deve ser objetivável, ou seja, representável a partir do estoque preexistente de relações consideradas como possíveis no interior do conjunto cultural considerado. Esta proposição é ilustrada por uma explicação da rejeição da domesticação animal pelas populações ameríndias da Amazônia.The present article defends the idea that we should subvert the usual procedure used to study the social genesis of techniques. The issue of the social genesis of techniques should be studied by considering, first and foremost, that which is conventionally called "technical choices." Habitually, tautological explanations are given in an attempt to explain the adaptive advantages that make a certain technique necessarily emerge. Rather than offering such explanations, the negative determinants for a technological choice are examined here. Negative determinants are sought with questions such as why did such technique not appear in that particular context where it could have possibly appeared? Any technique may be thought of as a relationship between man and the inorganic or live matter (which he himself is a part of). If so, then such a relationship can be objectified, that is, it can be represented with preexistent relationships considered possible in a given cultural group. This idea regarding technique is illustrated here with an explanation for the rejection by the Amazon Amerindian populations of animal domestication.

Let R = ⨁j≥0 Rj be a homogeneous Noetherian ring with irrelevant ideal R+ = ⨁j≥1 Rj. Let M, N be two finitely generated graded R-modules. Several results on the Artinianness, tameness and asymptotic property of the graded R-modules will be investigated. [ABSTRACT FROM AUTHOR]