The 'missing heritability' of common disorders: should health researchers care?

The Gene: An appraisal

The gene can be described as the foundational concept of modern biology. As such, it has spilled over into daily discourse, yet it is acknowledged among biologists to be ill-defined. Here, following a short history of the gene, I analyse critically its role in inheritance, evolution, development, and morphogenesis. Wilhelm Johannsen's genotype-conception, formulated in 1910, has been adopted as the foundation stone of genetics, giving the gene a higher degree of prominence than is justified by the evidence. An analysis of the results of the Long-Term Evolution Experiment (LTEE) with E. coli bacteria, grown over 60,000 generations, does not support spontaneous gene mutation as the source of variance for natural selection. From this it follows that the gene is not Mendel's unit of inheritance: that must be Johannsen's transmission-conception at the gamete phenotype level, a form of inheritance that Johannsen did not consider. Alternatively, I contend that biology viewed on the bases of thermodynamics, complex system dynamics, and self-organisation, provides a new framework for the foundations of biology. In this framework, the gene plays a passive role as a vital information store: it is the phenotype that plays the active role in inheritance, evolution, development, and morphogenesis.

The gene: An appraisal

The gene can be described as the foundational concept of modern biology. As such, it has spilled over into daily discourse, yet it is acknowledged among biologists to be ill-defined. Here, following a short history of the gene, I analyse critically its role in inheritance, evolution, development, and morphogenesis. Wilhelm Johannsen's genotype-conception, formulated in 1910, has been adopted as the foundation stone of genetics, giving the gene a higher degree of prominence than is justified by the evidence. An analysis of the results of the Long-Term Evolution Experiment (LTEE) with E. coli bacteria, grown over 60,000 generations, does not support spontaneous gene mutation as the source of variance for natural selection. From this it follows that the gene is not Mendel's unit of inheritance: that must be Johannsen's transmission-conception at the gamete phenotype level, a form of inheritance that Johannsen did not consider. Alternatively, I contend that biology viewed on the bases of thermodynamics, complex system dynamics and self-organisation, provides a new framework for the foundations of biology. In this framework, the gene plays a passive role as a vital information store: it is the phenotype that plays the active role in inheritance, evolution, development, and morphogenesis.

Advantaged socioeconomic conditions in childhood are associated with higher cognitive functioning but stronger cognitive decline in older age

There is increasing evidence that socioeconomic conditions early in life have an impact on cognitive functioning in later life. Based on the large longitudinal sample from SHARE we find a clear pattern in cognitive functioning in old age, related to childhood socioeconomic conditions: Those from more affluent households show higher levels of fluid intelligence in old age and experience stronger decline over time in executive functions. The latter phenomenon is not often documented. Although modifications in cognitive functioning with aging are inevitable, life course socioeconomic circumstances impact the timing of this process. We conclude that the etiology of cognitive aging is the result of multiple social processes, defined by the socioeconomic conditions in childhood and all along the life course.

Cognitive aging is characterized by large heterogeneity, which may be due to variations in childhood socioeconomic conditions (CSC). Although there is substantial evidence for an effect of CSC on levels of cognitive functioning at older age, results on associations with cognitive decline are mixed. We examined by means of an accelerated longitudinal design the association between CSC and cognitive trajectories from 50 to 96 years. Cognition included two functions generally found to decline with aging: delayed recall and verbal fluency. Data are from six waves of the Survey of Health, Aging, and Retirement in Europe (SHARE), conducted between 2004 and 2015 (n = 24,066 at baseline; 56% female, age 50+). We found a consistent CSC pattern in levels of cognitive functioning in later life. Older people with disadvantaged CSC had lower levels of cognitive functioning than those with more advantaged CSC. We also find that decline is almost 1.6 times faster in the most advantaged group compared with the most disadvantaged group. The faster decline for people with more advantaged CSC becomes less pronounced when we additionally control for adulthood socioeconomic conditions and current levels of physical activity, depressive symptoms, and partner status. Our findings are in line with the latency, pathway, and cumulative model and lend support to theories of cognitive reserve, stating that neuronal loss can no longer be repaired in people with more cognitive reserve once the underlying pathology is substantial and speed of decline is accelerated.

The global diabetes epidemic and the nonprofit state corporate complex: Equity implications of discourses, research agendas, and policy recommendations of diabetes nonprofit organizations

Important insights have been gained from studying how corporate social actors -- such as Big Tobacco or Big Food -- influence how global health issues are framed, debated, and addressed, and in so doing contribute to reproducing health inequities. Less attention has been paid to the role of nonprofit organizations (NPOs), even when all too often NPOs actively contribute to these inequities through normalizing discourses and practices that legitimize establishment views, poor public policies and existing relations of power. Our study attempts to fill this gap by assessing the influence on global health inequities of major NPOs -- specifically three disease associations -- whose mission includes preventing type 2 diabetes (henceforth diabetes) or reducing inequities in the global diabetes epidemic. No longer considered a "disease of prosperity", diabetes is known to affect the poor and racialized minorities disproportionately, in countries at all levels of income. While the contribution of the social and political determinants of health is well established, major NPOs ostensibly committed to eradicate, or at least moderate the effects of, diabetes give short shrift to these determinants, framing them at best as the context that promotes behaviours that combine with genetic predispositions to drive the inequitable, global distribution of diabetes. Drawing from Marxian theory and critical discourse analysis, we assess publicly available information - on educational and policy prescriptions, funding sources, corporate affiliations, funded research and social media presence -- pertaining to one Canadian, one US and one international NPO to identify discourses and practices that may contribute to the global, unequal distribution of diabetes and elaborate on their implications for health equity more broadly.

Basing Science Ethics on Respect for Human Dignity

A "no ethics" principle has long been prevalent in science and has demotivated deliberation on scientific ethics. This paper argues the following: (1) An understanding of a scientific "ethos" based on actual "value preferences" and "value repugnances" prevalent in the scientific community permits and demands critical accounts of the "no ethics" principle in science. (2) The roots of this principle may be traced to a repugnance of human dignity, which was instilled at a historical breaking point in the interrelation between science and ethics. This breaking point involved granting science the exclusive mandate to pass judgment on the life worth living. (3) By contrast, respect for human dignity, in its Kantian definition as "the absolute inner worth of being human," should be adopted as the basis to ground science ethics. (4) The pathway from this foundation to the articulation of an ethical duty specific to scientific practice, i.e., respect for objective truth, is charted by Karl Popper's discussion of the ethical principles that form the basis of science. This also permits an integrated account of the "external" and "internal" ethical problems in science. (5) Principles of the respect for human dignity and the respect for objective truth are also safeguards of epistemic integrity. Plain defiance of human dignity by genetic determinism has compromised integrity of claims to knowledge in behavioral genetics and other behavioral sciences. Disregard of the ethical principles that form the basis of science threatens epistemic integrity.

The Developmental Systems Approach and the Analysis of Behavior

The developmental systems approach is a perspective that has been adopted by increasing numbers of developmental scientists since it emerged in the twentieth century. The overview presented in this paper makes clear that proponents of this approach and proponents of modern behavior analysis should be natural allies. Despite some distinctions between the two schools of thought, the essential ideas associated with each are compatible with the other; in particular, scientists in both camps work to analyze the provenance of behavior and recognize the central role that contextual factors play in behavioral expression.

Epigenetic Alterations Associated with War Trauma and Childhood Maltreatment

Survivors of war trauma or childhood maltreatment are at increased risk for trauma-spectrum disorders such as post-traumatic stress disorder (PTSD). In addition, traumatic stress has been associated with alterations in the neuroendocrine and the immune system, enhancing the risk for physical diseases. Traumatic experiences might even affect psychological as well as biological parameters in the next generation, i.e. traumatic stress might have transgenerational effects. This article outlines how epigenetic processes, which represent a pivotal biological mechanism for dynamic adaptation to environmental challenges, might contribute to the explanation of the long-lasting and transgenerational effects of trauma. In particular, epigenetic alterations in genes regulating the hypothalamus-pituitary-adrenal axis as well as the immune system have been observed in survivors of childhood and adult trauma. These changes could result in enduring alterations of the stress response as well as the physical health risk. Furthermore, the effects of parental trauma could be transmitted to the next generation by parental distress and the pre- and postnatal environment, as well as by epigenetic marks transmitted via the germline. While epigenetic research has a high potential of advancing our understanding of the consequences of trauma, the findings have to be interpreted with caution, as epigenetics only represent one piece of a complex puzzle of interacting biological and environmental factors. Copyright © 2015 John Wiley & Sons, Ltd.