On the evolution of epigenetics via exaptation: A developmental systems perspective.

Evolution and development are interrelated processes influenced by genomic, epigenetic, and environmental factors. Epigenetic processes serve critical roles in development and operate as intermediaries that connect the genome to the rest of the world. Therefore, it is of interest to consider the evolution of epigenetic processes. The developmental systems perspective offers a distinctive, coherent, integrative way to understand the relationships between evolution, epigenetics, development, and the effects of experienced contexts. By adopting this perspective, this paper draws attention to the role of exaptation in the evolution of epigenetics in the RNA world and addresses the role of epigenetics in the later evolution of developmental processes such as cellular differentiation, learning, and memory. In so doing, the paper considers the appearance and functions of epigenetics in evolutionary history-sketching a pathway by which epigenetic processes might have evolved via exaptation and then contributed to the later development and evolution of phenotypes.

Polygenic scores ignore development and epigenetics, dramatically reducing their value.

Polygenic scores cannot elucidate the mechanisms that produce behavioral phenotypes (including "intelligence"). Therefore, they are unlikely to yield helpful interventions. Moreover, they are poor predictors of individuals' developmental outcomes. Burt's critique is well-supported by the details of molecular biology. Specifically, experiences affect epigenetic factors that influence phenotypes via how the genome functions, a fact that lends support to Burt's conclusions.

Development as explanation: Understanding phenotypic stability and variability after the failure of genetic determinism.

In the predominately gene-centered view of 20th century biology, the relationship between genotype and phenotype was essentially a relationship between cause and effect, between a plan and a product. Abandoning the idea of genes as inherited instructions or blueprints for phenotypes raises the question of how to best account for observed phenotypic stability and variability within and across generations of a population. We argue that the processes responsible for phenotypic stability and the processes responsible for phenotypic variability are one and the same, namely, the dynamics of development. This argument proposes that stability of phenotypic form is found not because of the transmission of genotypes, genetic programs, or the transfer of internal blueprints, but because similar internal and external conditions-collectively conceptualized as resources of development-can be reliably reconstituted in each generation. Variability of phenotypic form, which is an indispensable feature of any evolving system, relies on these same resources, but because the internal and external conditions of development are not reconstituted identically in succeeding generations, these conditions-and the phenotypes to which they give rise-will always be characterized by at least some variability.

How deep do we have to go to rehabilitate evolutionary psychology? Reply to Bjorklund et al. (2022).

Disciplines like evolutionary developmental psychology admirably focus on trying to rehabilitate narrow evolutionary psychology (NEP) from within, by adding a developmental focus to NEP's tenets of adaptationism and computationalism. We argue, however, that these tenets are fundamentally incompatible with taking psychology and its development seriously, and that the kinds of modifications introduced by evolutionary developmental psychologists do not go deep enough to qualitatively change the nondevelopmental outlook of NEP. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Evolving evolutionary psychology.

Which evolutionary theory can best benefit psychological theory, research, and application? The most well-known school of evolutionary psychology has a narrow conceptual perspective (a.k.a., "Narrow Evolutionary Psychology" or NEP). Proponents of NEP have long argued that their brand of evolutionary psychology represents a full-fledged scientific revolution, with Buss (2020) recently likening NEP's scientific impact to that of a Copernican or Darwinian paradigm shift. However, NEP stands on two traditions that are now the subjects of serious debate and revision: the neo-Darwinian adaptationist framework within evolutionary biology, and the computationalist "mind-as-computer" framework within cognitive science. Although NEP calls itself revolutionary, the significant revolutions taking place today in both evolutionary biology and cognitive science reveal NEP to be rooted in the orthodoxies of the past. We propose a more inclusive, developmental evolutionary psychology theory (DEPTH) better suited for our field in multiple ways, from acknowledging epigenesis to incorporating developmental science. To discern appropriate baselines for human nature and for human becoming, one must integrate developmental neuroscience, anthropology, and cognitive archeology. To be of value in addressing and remedying the challenges facing humanity, psychological theories must recognize the central importance of our plasticity, evolved developmental niche, and deep history. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Using confocal imaging approaches to understand the structure and function of osteocytes and the lacunocanalicular network.

Although overlooked in the past, osteocytes have come to the forefront of skeletal biology and are now recognized as a key cell type that integrates hormonal, mechanical and other signals to control bone mass through regulation of both osteoblast and osteoclast activity. With the surge of recent interest in osteocytes as bone regulatory cells and the discovery that they also function as endocrine regulators of phosphate homeostasis, there has been renewed interest in understanding the structure and function of these unique and relatively inaccessible cells. Osteocytes are embedded within the mineralized bone matrix and are housed within a complex lacunocanalicular system which connects them with the circulation and with other organ systems. This has presented unique challenges for imaging these cells. This review summarizes recent advances in confocal imaging approaches for visualizing osteocytes and their lacunocanalicular networks in both living and fixed bone specimens and discusses how computational approaches can be combined with live and fixed cell imaging techniques to generate quantitative outputs and predictive models. The integration of advanced imaging with computational approaches promises to lead to a more in depth understanding of the structure and function of osteocyte networks and the lacunocanalicular system in the healthy and aging state as well as in pathological conditions in bone.

The development of mental rotation ability across the first year after birth.

Mental rotation (MR) is the ability to imagine the appearance of an object from a different perspective. This ability is involved in many human cognitive and behavioral activities. We discuss studies that have examined MR in infants and its development across the first year after birth. Despite some conflicting findings across these studies, several conclusions can be reached. First, MR may be available to human infants as young as 3 months of age. Second, MR processes in infancy may be similar or identical to MR processes later in life. Third, there may be sex differences in MR performance, in general favoring males. Fourth, there appear to be multiple influences on infants' MR performance, including infants' motor activity, stimulus complexity, hormones, and parental attitudes. We conclude by calling for additional research to examine more carefully the causes and consequences of MR abilities early in life.

Spatial Thinking in Infancy: Origins and Development of Mental Rotation Between 3 and 10 Months of Age.

Mental rotation (MR) is the ability to transform a mental representation of an object so as to accurately predict how the object would look from a different angle (Sci 171:701-703, 1971), and it is involved in a number of important cognitive and behavioral activities. In this review we discuss recent studies that have examined MR in infants and the development of MR across the first year after birth. These studies have produced many conflicting results, yet several tentative conclusions can be reached. First, MR may be operational in infants as young as 3 months of age. Second, there may be sex differences in MR performance in infancy, in general favoring males, as there are in children and in adults. Third, there appear to be multiple influences on infants' MR performance, including infants' motor activity, stimulus or task complexity, hormones, and parental attitudes. We conclude by calling for additional research to examine more carefully the causes and consequences of MR abilities early in life.

Object exploration facilitates 4-month-olds' mental rotation performance.

How do infants learn to mentally rotate objects, to imagine them rotating through different viewpoints? One possibility is that development of infants' mental rotation (MR) is facilitated by visual and manual experience with complex objects. To evaluate this possibility, eighty 4-month-olds (40 females, 40 males) participated in an object exploration task with Velcro "sticky mittens" that allow infants too young to grasp objects themselves to nonetheless explore those objects manually as well as visually. These eighty infants also participated in a visual habituation task designed to test MR. Half the infants (Mittens First group) explored the object prior to the MR task, and the other half afterwards (Mittens Second group), to examine the role of immediate prior object experience on MR performance. We compared performance of male and female infants, but found little evidence for sex differences. However, we found an important effect of object exploration: The infants in the Mittens First group who exhibited the highest levels of spontaneous object engagement showed the strongest evidence of MR, but there were no consistent correlations between these measures for infants in the Mittens Second group. These findings suggest an important contribution from object experience to development of MR.

Gene × Environment interaction: What exactly are we talking about?

An ambiguity exists in how psychological scientists use the word "interaction." This word can refer to physical interactions between components that form the mechanisms in complex systems, but it can also refer to statistical interactions revealed by General Linear Statistical Models (e.g., Analyses of Variance). Statistical interactions indicate that the nature of the relationship between two variables depends on a third variable, but the discovery of such interactions does not constitute evidence of physical interactions between components in a system. Studies conducted using traditional behavioral genetics methods sometimes reveal statistical interactions between genes and environments, but the presence or absence of such interactions tell us surprisingly little about actual, physical interactions between genes and their contexts. This is important, because it is only the latter kinds of interactions that cause the development of behavioral phenotypes, including developmental disabilities. Therefore, when behavioral scientists discover (or fail to discover) Genotype × Environment interactions, it is important to exercise care in interpreting their meaning and in assessing the utility of such findings.

Early contributions to infants' mental rotation abilities.

Some cognitive abilities exhibit reliable gender differences, with females outperforming males in specific aspects of verbal ability, and males showing an advantage on certain spatial tasks. Among these cognitive gender differences, differences in mental rotation are the most robust, and appear to be present even in infants. A large body of animal research suggests that gonadal hormones, particularly testosterone, during early development could contribute to this gender difference in mental rotation. Also, substantial evidence supports an influence of socialization on mental rotation performance. The present study investigated the relationship of two types of factors, early postnatal testosterone exposure and parental attitudes about gender, to mental rotation performance in 61 healthy infants (29 males, 32 females). We measured salivary testosterone at two time points: 1-2.5 months of age and 5-6 months of age. Infants' mental rotation performance and parents' attitudes about gender were assessed at 5-6 months of age. As predicted, testosterone concentrations were significantly higher in boys than girls in early infancy (d = 0.54), and boys performed significantly better than girls on mental rotation (d = 0.64). A significant positive correlation between testosterone at age 1-2.5 months and mental rotation was found only in boys (r = 0.50, p = .01). A significant negative correlation between parents' gender-stereotypical attitudes and mental rotation performance was found only in girls (r = -.57, p = .002). These findings suggest that the early postnatal testosterone surge (also known as "mini-puberty") may have organizational influences on mental rotation performance in boys, and that parents may influence their daughters' mental rotation abilities beginning very early in life.

Overt and covert attention in infants revealed using steady-state visually evoked potentials.

Although looking-time methods have long been used to measure infant attention and investigate aspects of cognitive development, steady-state visually evoked potential (SSVEP) measures may be more sensitive or practical in some contexts. Here, we demonstrate habituation of infants' SSVEP amplitudes to a flickering checkerboard stimulus, and recovery of attention upon presentation of a novel checkerboard stimulus. This modulation of SSVEP amplitude was more robust than the modulation of looking time. In addition, we provide evidence of enhanced SSVEPs in response to covertly attended checkerboards flickering in peripheral visual fields, even while infants are fixating a central stimulus. These experiments provide the first evidence of habituation and recovery of infant SSVEP amplitudes, as well as the first evidence of sustained infant covert attention using SSVEPs. SSVEPs may be a sensitive, efficient measure for use in studying early cognitive development, in particular infants' overt and covert attention. (PsycINFO Database Record

Babies and math: A meta-analysis of infants' simple arithmetic competence.

Wynn's (1992) seminal research reported that infants looked longer at stimuli representing "incorrect" versus "correct" solutions of basic addition and subtraction problems and concluded that infants have innate arithmetical abilities. Since then, infancy researchers have attempted to replicate this effect, yielding mixed findings. The present meta-analysis aimed to systematically compile and synthesize all of the primary replications and extensions of Wynn (1992) that have been conducted to date. The synthesis included 12 studies consisting of 26 independent samples and 550 unique infants. The summary effect, computed using a random-effects model, was statistically significant, d = +0.34, p < .001, suggesting that the phenomenon Wynn originally reported is reliable. Five different tests of publication bias yielded mixed results, suggesting that while a moderate level of publication bias is probable, the summary effect would be positive even after accounting for this issue. Out of the 10 metamoderators tested, none were found to be significant, but most of the moderator subgroups were significantly different from a null effect. Although this meta-analysis provides support for Wynn's original findings, further research is warranted to understand the underlying mechanisms responsible for infants' visual preferences for "mathematically incorrect" test stimuli. (PsycINFO Database Record

The heritability fallacy.

The term 'heritability,' as it is used today in human behavioral genetics, is one of the most misleading in the history of science. Contrary to popular belief, the measurable heritability of a trait does not tell us how 'genetically inheritable' that trait is. Further, it does not inform us about what causes a trait, the relative influence of genes in the development of a trait, or the relative influence of the environment in the development of a trait. Because we already know that genetic factors have significant influence on the development of all human traits, measures of heritability are of little value, except in very rare cases. We, therefore, suggest that continued use of the term does enormous damage to the public understanding of how human beings develop their individual traits and identities. WIREs Cogn Sci 2017, 8:e1400. doi: 10.1002/wcs.1400 For further resources related to this article, please visit the WIREs website.

Behavioral epigenetics.

Why do we grow up to have the traits we do? Most 20th century scientists answered this question by referring only to our genes and our environments. But recent discoveries in the emerging field of behavioral epigenetics have revealed factors at the interface between genes and environments that also play crucial roles in development. These factors affect how genes work; scientists now know that what matters as much as which genes you have (and what environments you encounter) is how your genes are affected by their contexts. The discovery that what our genes do depends in part on our experiences has shed light on how Nature and Nurture interact at the molecular level inside of our bodies. Data emerging from the world's behavioral epigenetics laboratories support the idea that a person's genes alone cannot determine if, for example, he or she will end up shy, suffering from cardiovascular disease, or extremely smart. Among the environmental factors that can influence genetic activity are parenting styles, diets, and social statuses. In addition to influencing how doctors treat diseases, discoveries about behavioral epigenetics are likely to alter how biologists think about evolution, because some epigenetic effects of experience appear to be transmissible from generation to generation. This domain of research will likely change how we think about the origins of human nature. WIREs Syst Biol Med 2017, 9:e1333. doi: 10.1002/wsbm.1333 For further resources related to this article, please visit the WIREs website.

Seeing double: 5-month-olds' mental rotation of dynamic, 3D block stimuli presented on dual monitors.

Mental rotation (MR) involves the ability to predict how an object will look once it has been rotated into a new orientation in space. To date, studies of MR in infants have tested this ability using abstract stimuli presented using a single display. Evidence from existing studies suggests that using multiple displays may affect an infant's performance in some kinds of MR tasks. This study used Moore & Johnson's (2008) simplified Shepard-Metzler objects in a dual-monitor MR task presented to five-month-old infants. Evidence for MR in infancy was found. These findings have implications for MR testing in infancy and the influence of display properties on infant MR performance.

Antigen-Specific Binding of Multivalent Soluble Antigen Arrays Induces Receptor Clustering and Impedes B Cell Receptor Mediated Signaling.

A pressing need exists for autoimmune disease therapies that act in an antigen-specific manner while avoiding global immunosuppression. Multivalent soluble antigen arrays (SAgAPLP:LABL), designed to induce tolerance to a specific multiple sclerosis autoantigen, consist of a flexible hyaluronic acid (HA) polymer backbone cografted with multiple copies of autoantigen peptide (PLP) and cell adhesion inhibitor peptide (LABL). Previous in vivo studies revealed copresentation of both signals on HA was necessary for therapeutic efficacy. To elucidate therapeutic cellular mechanisms, in vitro studies were performed in a model B cell system to evaluate binding and specificity. Compared to HA and HA arrays containing only grafted PLP or LABL, SAgAPLP:LABL displaying both PLP and LABL exhibited greatly enhanced B cell binding. Furthermore, the binding avidity of SAgAPLP:LABL was primarily driven by the PLP antigen, determined via flow cytometry competitive dissociation studies. Fluorescence microscopy showed SAgAPLP:LABL induced mature receptor clustering that was faster than other HA arrays with only one type of grafted peptide. SAgAPLP:LABL molecules also reduced and inhibited IgM-stimulated signaling as discerned by a calcium flux assay. The molecular mechanisms of enhanced antigen-specific binding, mature receptor clustering, and dampened signaling observed in B cells may contribute to SAgAPLP:LABL therapeutic efficacy.

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.

Advances in explosives analysis--part II: photon and neutron methods.

The number and capability of explosives detection and analysis methods have increased dramatically since publication of the Analytical and Bioanalytical Chemistry special issue devoted to Explosives Analysis [Moore DS, Goodpaster JV, Anal Bioanal Chem 395:245-246, 2009]. Here we review and critically evaluate the latest (the past five years) important advances in explosives detection, with details of the improvements over previous methods, and suggest possible avenues towards further advances in, e.g., stand-off distance, detection limit, selectivity, and penetration through camouflage or packaging. The review consists of two parts. Part I discussed methods based on animals, chemicals (including colorimetry, molecularly imprinted polymers, electrochemistry, and immunochemistry), ions (both ion-mobility spectrometry and mass spectrometry), and mechanical devices. This part, Part II, will review methods based on photons, from very energetic photons including X-rays and gamma rays down to the terahertz range, and neutrons.