The standard behavioral index for human consciousness is the ability to report events with accuracy. While this method is routinely used for scientific and medical applications in humans, it is not easy to generalize to other species. Brain evidence may lend itself more easily to comparative testing. Human consciousness involves widespread, relatively fast low-amplitude interactions in the thalamocortical core of the brain, driven by current tasks and conditions. These features have also been found in other mammals, which suggests that consciousness (...) is a major biological adaptation in mammals. We suggest more than a dozen additional properties of human consciousness that may be used to test comparative predictions. Such homologies are necessarily more remote in non-mammals, which do not share the thalamocortical complex. However, as we learn more we may be able to make “deeper” predictions that apply to some birds, reptiles, large-brained invertebrates, and perhaps other species. (shrink)
Many traditional attempts to show that nonhuman animals are deserving of moral consideration have taken the form of an argument by analogy. However, arguments of this kind have had notable weaknesses and, in particular, have not been able to convince two kinds of skeptics. One of the most important weaknesses of these arguments is that they fail to provide theoretical justifications for why particular physiological similarities should be considered relevant. This paper examines recent empirical research on pain and, in particular, (...) explores the implications of the dissociation between the sensory and the affective pain pathways. It is argued that these results show that the belief that nonhuman animals experience pain in a morally relevant way is reasonable, though not certain. It is further argued that the proposal to explore the relationship between consciousness and various forms of learning challenges the aforementioned skeptics to provide more physiological details for their claims that nonhuman mammals are probably not conscious. (shrink)
Burrowing mammals are ubiquitous on farms in South Africa and can hinder agricultural practices. This study explored farmer perspectives of these species, and specifically the factors that influence these perspectives. Forty-four farmers responded to a questionnaire that assessed their ecological knowledge of, tolerance towards and lethal management of burrowing mammals that occur on their farms. The results from generalised linear models showed that neither farmer age, nor level of education are accurate predictors of ecological knowledge, overall tolerance towards burrowers, or (...) their lethal management. Knowledge of burrowing mammals showed a significant relationship with tolerance, with more knowledgeable individuals displaying higher levels of tolerance. However, a farmer’s overall tolerance towards burrowing species did not affect the number of species managed. Our results also suggest that different values are attached to different species when it comes to lethal management. Thus, farmers commonly controlled the numbers of the problem rodent species, Highveld gerbil and Cape ground squirrel, but were less likely to manage black-backed jackal and warthog, even when experiencing these as problematic. We suggest that the larger, more charismatic species possibly evoke more sympathy from farmers. Agro-ecosystems are likely to become increasingly important for conservation in the future, and we encourage continued studies on the environmental attitudes and approaches of agricultural practitioners as a means to understanding the current status and future trends in ecologically sustainable agriculture. (shrink)
The primal motivational systems of all mammals are constituted of the evolved affective brain networks that gauge key survival issues. However, since progress in functional neuroscience has historically lagged behind conceptual developments in psychological science, motivational processes have traditionally been anchored to behavioral rather than neural and affective issues. Attempts to retrofit neuroaffective issues onto established psychological-conceptual structures are problematic, especially when fundamental evidence for primal affective circuits, and their neural nature, comes largely from animal research. This article provides a (...) synopsis of our growing understanding of primary-process emotional systems of mammalian brains and minds, which provides a new empirically based infrastructure for higher levels of human theorizing. (shrink)
The present article discusses different basic semiotic-scientific postulates regarding mammals’ sign activity. On the one hand, there are arguments denying animals sign activity, according to which mammals are not capable of semantic generalization on the basis of conventional linguistic values. According to another approach, mammals’ sign activity can be considered as means of ecological adaptation, that is, the features of animal behaviour based on the information, received by them through their habitat characteristics without direct visual contacts with their kind. Movement (...) elements, behavioural reactions of similar motivation and parameters of the sign field, which represents an animal’s sign-information environment, may have some numerical expression and can becalculated depending on the research tasks. Formalization of the animal activity implies simultaneous consideration of the following parameters: magnitude,intensity, anisotropy and the value of a given sign object. (shrink)
The circadian clock is a cell autonomous oscillator that controls many aspects of physiology through generating rhythmic gene expression in a time of day dependent manner. In addition, in endothermic mammals body temperature cycles contribute to rhythmic gene expression. These body temperature‐controlled rhythms are hard to distinguish from classic circadian rhythms if analyzed in vivo in endothermic organisms. However, they do not fulfill all criteria of being circadian if analyzed in cell culture or in conditions where body temperature of an (...) endothermic organism can be manipulated. Here we review and compare these characteristics, discuss the core clock independent mechanism of temperature‐controlled alternative splicing and highlight the requirement of double‐checking rhythms that appear circadian within an endothermic organism in a system that allows temperature manipulation. (shrink)
Can mammalian mothers adaptively control the sex of their offspring? The influential Trivers-Willard hypothesis proposes that when maternal condition increases the fitness of sons more than that of daughters, the proportion of sons produced should increase with maternal condition. Studies of mammals, however, often fail to support this hypothesis. This article highlights recent advances, including studies on the assumptions of the TWH and physiological mechanisms for sex-ratio manipulation. Particular emphasis is placed on how factors such as paternal quality, maternal reproductive (...) costs and environmental conditions experienced by mothers early in life can mask/alter the expected relationship between maternal condition and offspring sex ratio or lead to apparent support for the TWH. While there is growing evidence that sex ratio around conception may be maternally and paternally manipulated, a challenge for future studies on sex allocation is to integrate how multiple and potentially opposite selective pressures affect offspring sex ratio. The relationship between offspring sex and maternal condition lies at the heart of one of the most controversial hypotheses in evolutionary biology. This review highlights recent findings on the Trivers-Willard hypothesis with particular emphasis on factors which may mask the relationship of interest or falsely demonstrate it. (shrink)
Observations on the morphological and functional similarity between embryonic or trophoblast tissues and tumors are very old. Over a period of time many investigators have created different hypotheses on the origin of cancerogenesis or tumor efficiency in relation to the host immune system. Some of these ideas have been rejected but many of them are still current. A presumption of the inefficiency of anti-tumor immunity in mammals due to the high similarity between trophoblast and embryonic cells to tumor cells is (...) very real. The mechanisms for the escape of tumors from the immune response are very similar to the mechanisms for the escape of a fetoplacental unit from the maternal immune response. The similarity between these two mechanisms is so great that any randomness must be banished. At the same time, an incidence of malignant tumors and the types of more frequent tumors in non-mammalian vertebrates is significantly different to that in mammals. Lastly, the mechanisms of anti-tumor immunity in mammals are substantially different from the mechanisms of anti-tumor immunity in other classes of vertebrates. These facts indicate that the immune system of mammals during anti-tumor immune response is tricked by the similarity between tumor cells and trophoblast or other placental cells. From this aspect, our conclusion is that anti-tumor immunity failure in mammals can be defined as an immunoreproductive phenomenon, which is developed under the evolutionary pressure of autoimmunity and reproductive effectiveness. (shrink)
The view that female mammals are more docile appears to arise in part from imposing human values on animal studies. Many reports of sexual dimorphism in physical aggression favouring the male in laboratory rodents appear to select circumstances where that expectation is supported. Other situations that favour the expression of conflict in females have been (until recently) relatively little studied. Although female rodents generally do not show the “ritualised” forms of conflict that characterise male sexual competition, they can use notably (...) damaging strategies (especially if they are of short duration). Such considerations might weigh in the selection of strategies by our own species. (shrink)
(1941). A survey of the growth of knowledge about certain parts of the foetal cardio-vascular apparatus, and about the foetal circulation, in Man and some other mammals. Part I: Galen to Harvey. Annals of Science: Vol. 5, No. 1, pp. 57-89.
The use of anecdotes is not a viable research strategy to study animal culture. Social learning processes can often be documented with careful quantitative analyses of observational data. Unfortunately, suggestions that killer whales engage in teaching are entirely based on subjective interpretations of qualitative observations. Thus, of teaching in killer whales cannot be used to argue for the occurrence of culture in marine mammals.
Because network scaling costs tend to limit absolute brain size, Striedter suggests that large cetacean brains must have evolved some novel ways to cope with these costs. A new analysis of available data shows that the scaling pattern of interhemispheric connectivity in cetaceans is isometric and differs from that observed in terrestrial mammals.
Regenerative medicine promises to greatly impact on human health by improving repair outcomes in a range of tissues and injury contexts. Successful therapies will rely on identifying both intrinsic and extrinsic biological circuits that control wound healing, proliferation, cell survival, and developmental cell fate. Animals such as the zebrafish and the salamander display powerful examples of near‐perfect regeneration and scar‐free healing in a range of injury contexts not attained in mammals. By studying regeneration in a range of highly regenerative species (...) that maintain regenerative potential throughout life, many instructive and permissive factors have been identified that could assist in the development of regenerative therapies. This review highlights some of the recent observations in immune regulation, epigenetic regulation, stem cell mobilization, and regenerative signatures that have improved our understanding of the regenerative process. Potential opportunities in harnessing this knowledge for future translation into the clinic are discussed. (shrink)
Fossil remains witness the relationship between the appearance of the middle ear and the expansion of the brain in early mammals. Nevertheless, the lack of detachment of ear ossicles in the mammaliaform Morganucodon, despite brain enlargement, points to other factors that triggered brain expansion in early mammals. Moreover, brain expansion in some early mammalian groups seems to have favored brain regions other than the cortex.
The environment can have a long‐lasting influence on an individual's physiology and behavior. While some environmental conditions can be beneficial and result in adaptive responses, others can lead to pathological behaviors. Many studies have demonstrated that changes induced by the environment are expressed not only by the individuals directly exposed, but also by the offspring sometimes across multiple generations. Epigenetic alterations have been proposed as underlying mechanisms for such transmissible effects. Here, we review the most relevant literature on these changes (...) and the developmental stages they affect the most. We discuss current evidence for transgenerational effects of prenatal and postnatal factors on bodily functions and behavioral responses, and the potential epigenetic mechanisms involved. We also discuss the need for a careful evaluation of the evolutionary importance with respect to health and disease, and possible directions for future research in the field. (shrink)
Perception is a first-person internal sensation induced within the nervous system at the time of arrival of sensory stimuli from objects in the environment. Lack of access to the first-person properties has limited viewing perception as an emergent property and it is currently being studied using third-person observed findings from various levels. One feasible approach to understand its mechanism is to build a hypothesis for the specific conditions and required circuit features of the nodal points where the mechanistic operation of (...) perception take place for one type of sensation in one species and to verify it for the presence of comparable circuit properties for perceiving a different sensation in a different species. The present work explains visual perception in mammalian nervous system from a first-person frame of reference and provides explanations for the homogeneity of perception of visual stimuli above flicker fusion frequency, the perception of objects at locations different from their actual position, the smooth pursuit and saccadic eye movements, the perception of object borders, and perception of pressure phosphenes. Using results from temporal resolution studies and the known details of visual cortical circuitry, explanations are provided for (a) the perception of rapidly changing visual stimuli, (b) how the perception of objects occurs in the correct orientation even though, according to the third-person view, activity from the visual stimulus reaches the cortices in an inverted manner and (c) the functional significance of well-conserved columnar organization of the visual cortex. A comparable circuitry detected in a different nervous system in a remote species-the olfactory circuitry of the fruit fly Drosophila melanogaster-provides an opportunity to explore circuit functions using genetic manipulations, which, along with high-resolution microscopic techniques and lipid membrane interaction studies, will be able to verify the structure-function details of the presented mechanism of perception. (shrink)
The present study combines dehumanization research with the concept of organizational trust to examine how employees perceive various types of maltreatment embedded within the organizational practices that form the ethical climate of an organization. With the help of grounded theory methodology, we analyzed 188 employment exit interview transcripts from an ICT subcontracting company. By examining perceived trustworthiness and perceived humanness, we found that dehumanizing employees can deteriorate trust within organizations. The violations found in the empirical material were divided into animalistic (...) and mechanistic forms of dehumanization and linked to perceived integrity and benevolence, respectively. Based on the results, a model describing the link between dehumanization and trust is presented and discussed in relation to the ways in which perceptions of humanness become rooted in practices and affect the basic assumptions underlying ethical organizational behavior. (shrink)
Histone acetylation has been recognized as an important post‐translational modification of core nucleosomal histones that changes access to the chromatin to allow gene transcription, DNA replication, and repair. Histone acetyltransferases were initially identified as co‐activators that link DNA‐binding transcription factors to the general transcriptional machinery. Over the years, more chromatin‐binding modes have been discovered suggesting direct interaction of histone acetyltransferases and their protein complex partners with histone proteins. While much progress has been made in characterizing histone acetyltransferase complexes biochemically, cell‐free (...) activity assay results are often at odds with in‐cell histone acetyltransferase activities. In‐cell studies suggest specific histone lysine targets, but broad recruitment modes, apparently not relying on specific DNA sequences, but on chromatin of a specific functional state. Here we review the evidence for general versus specific roles of individual nuclear lysine acetyltransferases in light of in vivo and in vitro data in the mammalian system. (shrink)
Rendell and Whitehead argue persuasively that individual foraging specializations, if socially learned, are examples of cetacean culture. However, they discount ecological variation experienced by individuals within a population as a factor in such behavior. I suggest that ecological variation may play an important role in individual foraging specializations and describe several ecological parameters that may help us understand the high frequency of this interesting behavior in the marine habitat.