Experimental evolution, loss-of-function mutations, and "the first rule of adaptive evolution"

Adaptive evolution can cause a species to gain, lose, or modify a function; therefore, it is of basic interest to determine whether any of these modes dominates the evolutionary process under particular circumstances. Because mutation occurs at the molecular level, it is necessary to examine the molecular changes produced by the underlying mutation in order to assess whether a given adaptation is best considered as a gain, loss, or modification of function. Although that was once impossible, the advance of molecular biology in the past half century has made it feasible. In this paper, I review molecular changes underlying some adaptations, with a particular emphasis on evolutionary experiments with microbes conducted over the past four decades. I show that by far the most common adaptive changes seen in those examples are due to the loss or modification of a pre-existing molecular function, and I discuss the possible reasons for the prominence of such mutations.     

Clinical ethics and nursing: "yes" to caring, but "no" to a female ethics of care

According to a contemporary school of thought there is a specific female approach to ethics which is based not on abstract "male" ethical principles or rules, but on "care". Nurses have taken a keen interest in these female approaches to ethics. Drawing on the views expounded by Carol Gilligan and Nel Noddings, nurses claim that a female "ethics of care" better captures their moral experiences than a traditional male "ethics of justice". This paper argues that "care" is best understood in a dispositional sense, that is, as sensitivity and responsiveness to the particularities of a situation and the needs of "concrete" others. While "care", in this sense, is necessary for ethics, it is not sufficient. Ethics needs "justice" as well as "care". If women and nurses excessively devalue principles and norms, they will be left without the theoretical tools to condemn some actions or practices, and to defend others. They will, like generations of nurses before them, be condemned to silence.     

CLINICAL ETHICS AND NURSING: "YES" TO CARING, BUT "NO" TO A FEMALE ETHICS OF CARE

According to a contemporary school of thought there is a specific female approach to ethics which is based not on abstract "male" ethical principles or rules, but on "care". Nurses have taken a keen interest in these female approaches to ethics. Drawing on the views expounded by Carol Gilligan and Nel Noddings, nurses claim that a female "ethics of care" better captures their moral experiences than a traditional male "ethics of justice". This paper argues that "care" is best understood in a dispositional sense, that is, as sensitivity and responsiveness to the particularities of a situation and the needs of "concrete" others. While "care", in this sense, is necessary for ethics, it is not sufficient. Ethics needs "justice" as well as "care". If women and nurses excessively devalue principles and norms, they will be left without the theoretical tools to condemn some actions or practices, and to defend others. They will, like generations of nurses before them, be condemned to silence.     

Directional bias as a component of social behaviour with special reference to the Mallard, Anas platyrhynchos

Three types of "shake", given by male Mallards, Anas platyrhynchos, during Social Display, exhibit a crious "directional bias" in that the first sideways turn of the head tends to be made towards one of the females present. An investigation of the phenomenon by means of film suggests that directional bias reliably reflects a male's "interest" in a particular female. Evolutionary implications and the possible role of directional bias in social communication are briefly discussed.     

Reducing ambiguity in describing plant–insect interactions: "preference", "acceptability" and "electivity"

Ecologists and evolutionary biologists have a common interest in plant–insect interactions. Ecologists develop terminology describing patterns of association between plants and insects, while evolutionary biologists use the same words to denote potentially heritable traits of individuals. Use of the same terms to describe both traits of the interaction and traits of the organisms hinders communication. An example is "preference", often used by ecologists to denote properties of the plant–insect interaction and by behavioural or evolutionary biologists to denote insect traits. The existing term "electivity" could be incorporated into the lexicon of plant–insect interactions to supplant the ecological use of "preference". The term "preference" would then denote a behavioural trait of the insect. The mirror-image trait of the plant would be "acceptability". This could be a step towards a common terminology that would be usable by both ecologists and evolutionists.     

Signs, communication, and language

Noting the vagueness and confusion in the literature on animal behavior with regard to the phenomenon of communication, an attempt is made to define “sign” and “communication” from the point of view of cybernetics, drawing also on Susanne Langer's philosophy of symbols. The author argues that neither communication nor language can be successfully investigated as long as the dogmatic behaviorist's taboo against goal-directed or purposive activities is maintained. In accord with recent developments in feedback theory, he shows that the cyberneticist's concept of purpose can be used quite legitimately in the scientific analysis of behavior and that it makes possible a viable classification of signs as well as the discrimination of communication from other types of interaction. In conclusion some of Hockett's “design features” of language are discussed and an attempt is made to formulate criteria for the form of communcation that should be called linguistic.     

Bioethics for clinicians: 12. Ethical dilemmas that arise in the care of pregnant women: rethinking "maternal-fetal conflicts".

When a pregnant woman makes a decision or acts in a manner that may be detrimental to the health and well-being of her fetus, her physician may be faced with an ethical dilemma. Is the physician''s primary duty to respect the woman''s autonomy, or to promote behaviour that may be in the best interest of the fetus? The controversial concept of "fetal rights" or the "fetus as a patient" contributes to the notion that the pregnant woman and her fetus are potential adversaries. However, Canadian law has upheld women''s right to life, liberty and security of the person and has not recognized fetal rights. If a woman is competent and refuses medical advice, her decision must be respected even if the physician believes that her fetus will suffer as a result. Coercion of the woman is not permissible no matter what appears to be in the best interest of the fetus.     

An even "newer" animal phylogeny

Metazoa are one of the great monophyletic groups of organisms. They comprise several major groups of organisms readily recognizable based on their anatomy. These major groups include the Bilateria (animals with bilateral symmetry), Cnidaria (jellyfish, corals and other closely related animals), Porifera (sponges), Ctenophores (comb jellies) and a phylum currently made up of a single species, the Placozoa. Attempts to systematize the relationships of these major groups as well as to determine relationships within the groups have been made for nearly two centuries. Many of the attempts have led to frustration, because of a lack of resolution between and within groups. Other attempts have led to "a new animal phylogeny". Now, a study by Dunn et al., using the expresssed sequence tag (EST) approach to obtaining high-throughput large phylogenetic matrices, presents an "even newer" animal phylogeny. There are two major aspects of this study that should be of interest to the general biological community. First, the methods used by the authors to generate their phylogenetic hypotheses call for close examination. Second, the relationships of animal taxa in their resultant trees also prompt further discussion.     

Light-mediated "conversation" among microorganisms

Light emitted from a wide variety of microorganisms was considered previously as a waste product. However, it is becoming apparent that it might be involved in microbial communication. This paper presents information on such a novel mode of communication in different microorganisms.     

On hits and being hit on: error management theory,signal detection theory,and the male sexual overperception bias

Although Error Management Theory (EMT) can explain male sexual overperception, more advanced Signal Detection Theory (SDT) analyses can identify sensitivity and bias separately. An SDT analysis of perceptions of relatively clear interest/disinterest signals (Study 1) found that sensitivity to sexual interest/disinterest signals drove participants' perceptions, rather than an overall bias to perceive sexual interest. Cues of interest were generally underperceived, while sensitivity and accuracy were uniformly high. EMT analysis also found overall sexual interest underperception, but with men slightly overperceiving interest relative to women. These discrepant results were due to EMT using difference scores, which obscure baseline perceptions for men and women. Individual differences in life history strategy, mating strategy, and mate value did not affect sensitivity or bias. Study 2 largely replicated these results using more ambivalent scenarios, except EMT analyses found men's misperception to be significantly larger than women's, despite being closer to pre-rated communication levels. These results show that sexual communication may be more nuanced than previously thought, and that an SDT analysis is more appropriate for such data.     

A "wringing" endorsement for myosin phosphorylation in the heart

On average, the human heart beats 100,000 times a day and it is in a person's best interest to have the heart move blood as efficiently as possible. For example, imagine a wet rag: squeezing the rag in your fist does not remove as much water as wringing the same rag between two hands. Thus, in hearts as in rags, torsional wringing, as opposed to squeezing, more thoroughly empties the heart of blood. Recent reports indicate that the activity and the distribution of myosin light chain kinase (MLCK) in the myocardium is key to this process. MLCK-dependent phosphorylation of the regulatory light chain (R-LC), a subunit of the myosin molecule, may lead to increased force and power of contraction. It is the asymmetric distribution of MLCK in the myocardium that allows for torsional wringing rather than squeezing. Specifically targeting MLCK expression in the heart might, in the future, lead to promising therapies that counteract cardiomyopathy.     

The Physician and Industry

Many employers are interested in helping their employees improve and maintain health through a program of preventive medicine designed to supplement health services which already exist in the community. The objectives of such a health program can be attained only through team work between physicians, both within and outside industry. Such specific objectives as the development of measures for the maintenance and improvement of health and the prevention of disease; the provision of readily available diagnostic, treatment and counselling services; the rehabilitation of disabled employees; and the effective administration of sick-benefit plans require the closest communication and co-operation among the occupational health service, the private physician, and other health and welfare agencies. Only by such liaison can the maximum benefits of both preventive and curative medicine be extended to the employee—in his best interest as well as that of the community and the employer.     

In the patient's best interest--a call to action,a call to balance

Nurses, physicians, and other healthcare professionals often complain that a loss of freedom or other obstacles hinder their ability to act in the best interest of the patient. These barriers cause professional burnout and moral outrage, and may contribute to a migration away from medicine or, more broadly, healthcare. Understanding the historical underpinnings of the phrase "in the patient's best interest," and realizing that healthcare, which is fundamentally a moral enterprise must be built on sound business principles can help healthcare professionals reframe the issue, and reclaim their original commitment to a difficult path.     

Putting the "landscape" in landscape genetics

Landscape genetics has emerged as a new research area that integrates population genetics, landscape ecology and spatial statistics. Researchers in this field can combine the high resolution of genetic markers with spatial data and a variety of statistical methods to evaluate the role that landscape variables play in shaping genetic diversity and population structure. While interest in this research area is growing rapidly, our ability to fully utilize landscape data, test explicit hypotheses and truly integrate these diverse disciplines has lagged behind. Part of the current challenge in the development of the field of landscape genetics is bridging the communication and knowledge gap between these highly specific and technical disciplines. The goal of this review is to help bridge this gap by exposing geneticists to terminology, sampling methods and analysis techniques widely used in landscape ecology and spatial statistics but rarely addressed in the genetics literature. We offer a definition for the term "landscape genetics", provide an overview of the landscape genetics literature, give guidelines for appropriate sampling design and useful analysis techniques, and discuss future directions in the field. We hope, this review will stimulate increased dialog and enhance interdisciplinary collaborations advancing this exciting new field.     

Medical housing "lines".

General practitioners are often asked for medical certificates (housing "lines") by applicants for council housing who claim to have medical problems requiring housing priority. The results of a survey by questionnaire showed that general practitioners in Edinburgh do not know how the housing system works and that they seem to overestimate their patients'' chances of obtaining suitable council housing. General practitioners need to know how the housing system works, and communication between general practitioners and housing departments should be improved. A comparison was also made between the number of medical points awarded by a community medicine specialist and a group of general practitioners who had written housing "lines" for their patients. The general practitioners tended to award more points than the specialist. Social priority for housing should be recognised as an independent factor and a new category of top social priority added.     

The doctor and the "delta factor": Walker Percy and the dilemma of modern medicine

As medical science progresses, a tension has developed between the art of medicine, which deals with patients as individual persons, and the science itself, which focuses on the objective pathology.This tension is furthered as medicine identifies itself increasingly with science. To explore the consequences of this unbalanced identification, and the strain it places on the physician-patient relationship, this article examines the thought of Walker Percy, and in particular his novel The Second Coming. In this novel, Percy, a physician by training, presents a case of a patient suffering at the hands of medicine-turned-reductionist. The novel highlights the breakdown of communication between physician and patient within modern medicine, and raises important questions about how to best understand, and thereby preserve, medicine's true art.     

Mounting Media for phase Microscope Specimens

-Results with phase microscopy can often be improved by the proper selection of mounting media. Temporary mounts can first be made in liquid mixtures of water and glycerol, butyl carbitol and alpha-chloronaphthalene, alpha-chloronaphthalene and alpha-bromonaphthalene or alpha-bromonaphthalene with methylene iodide to determine what index liquid serves best to emphasize structures of primary interest. Once this has been determined, permanent mounts can be prepared by the substitution of a solid mounting medium that most closely approaches the refractive index of the liquid.     

Consensus decision making in animals

Individual animals routinely face decisions that are crucial to their fitness. In social species, however, many of these decisions need to be made jointly with other group members because the group will split apart unless a consensus is reached. Here, we review empirical and theoretical studies of consensus decision making, and place them in a coherent framework. In particular, we classify consensus decisions according to the degree to which they involve conflict of interest between group members, and whether they involve either local or global communication; we ask, for different categories of consensus decision, who makes the decision, what are the underlying mechanisms, and what are the functional consequences. We conclude that consensus decision making is common in non-human animals, and that cooperation between group members in the decision-making process is likely to be the norm, even when the decision involves significant conflict of interest.     

Approximate likelihood-ratio test for branches: A fast, accurate, and powerful alternative

We revisit statistical tests for branches of evolutionary trees reconstructed upon molecular data. A new, fast, approximate likelihood-ratio test (aLRT) for branches is presented here as a competitive alternative to nonparametric bootstrap and Bayesian estimation of branch support. The aLRT is based on the idea of the conventional LRT, with the null hypothesis corresponding to the assumption that the inferred branch has length 0. We show that the LRT statistic is asymptotically distributed as a maximum of three random variables drawn from the chi(0)2 + chi(1)2 distribution. The new aLRT of interior branch uses this distribution for significance testing, but the test statistic is approximated in a slightly conservative but practical way as 2(l1- l2), i.e., double the difference between the maximum log-likelihood values corresponding to the best tree and the second best topological arrangement around the branch of interest. Such a test is fast because the log-likelihood value l2 is computed by optimizing only over the branch of interest and the four adjacent branches, whereas other parameters are fixed at their optimal values corresponding to the best ML tree. The performance of the new test was studied on simulated 4-, 12-, and 100-taxon data sets with sequences of different lengths. The aLRT is shown to be accurate, powerful, and robust to certain violations of model assumptions. The aLRT is implemented within the algorithm used by the recent fast maximum likelihood tree estimation program PHYML (Guindon and Gascuel, 2003).