Although most discussions today start from the assumption that the secular rise in IQ must be environmental in origin, three reasons warrant giving the genetic phenomenon heterosis a closer look as a potential cause. First, it easily accounts for both the high heritability and low shared environmental effects seen in IQ, findings that are…

Epidemiological and clinical studies have consistently reported associations between smoking and posttraumatic stress disorder (PTSD). This study analyzed diagnostic interview data on 6,744 members of the Vietnam Era Twin Registry to clarify the PTSD-smoking relation and to examine whether genetic liability for smoking moderated this relation.…

This article analyzes the power of ambiguous metaphors to present scientific novelty. Its focus is a series of papers by the prominent population biologist W. D. Hamilton in which he redefined the meaning of biological altruism. In particular, the article draws on Kenneth Burke's dramatistic pentad to examine why suggestions of motive are so…

The cGMP-dependent protein kinase (PKG) has many cellular functions in vertebrates and insects that affect complex behaviors such as locomotion and foraging. The "foraging" ("for") gene encodes a PKG in "Drosophila melanogaster." Here, we demonstrate a function for the "for" gene in sensory responsiveness and nonassociative learning. Larvae of the…

To investigate whether motor skill learning depends on de novo protein synthesis, adult rats were trained in an acrobatic locomotor task (accelerating rotarod) for 7 d. Animals were systemically injected with cycloheximide (CHX, 0.5 mg/kg, i.p.) 1 h before sessions 1 and 2 or sessions 2 and 3. Control rats received vehicle injections before…

We previously reported that five repeated pulses of 5-HT lead to down-regulation of the TM-apCAM isoform at the surface of "Aplysia" sensory neurons (SNs). We here examined whether apCAM down-regulation is required for 5-HT-induced long-term facilitation. We also analyzed the role of the cytoplasmic and extracellular domains by overexpressing…

We present and discuss three examples of misapplication of the notion of conditional probability. In each example, we present the problem along with a published and/or well-known incorrect--but seemingly plausible--solution. We then give a careful treatment of the correct solution, in large part to show how careful application of basic probability…

The etiology of intellectual disability was studied both in incident (n = 9,432) and prevalent (n = 9,351) populations in a one-year birth cohort born in Northern Finland in 1985-1986. Data from multiple sources were used to follow the children until the age of 11.5 years. Of the incident cases (n = 119) with intellectual disabilities, 66.4% had…

This study compared the contribution of genes and environment to teacher-rated reactive and proactive aggression in 6-year-old twin pairs (172 pairs: 55 monozygotic girls, 48 monozygotic boys, 33 dizygotic girls, 36 dizygotic boys). Genetic effects accounted for 39% of the variance of reactive aggression and for 41% of the variance of proactive…

Providing a biotechnology experience for students can be challenging on several levels, and time is a real constraint for many experiments. Many DNA based methods require a gel electrophoresis step, and although some biotechnology procedures have convenient break points, gel electrophoresis does not. In addition to the time required for loading…

Attention-Deficit/Hyperactivity Disorder (ADHD) is a neurobiological disorder that is characterized by developmentally inappropriate levels of inattention, impulsivity, and hyperactivity. Between 3% and 7% of school-aged children are affected by ADHD. ADHD is a lifespan condition that affects children, adolescents and adults of all ages. It…

Researchers are becoming aware of the influence of students' presuppositions in directing their construction of science concepts. When these are entrenched and drastically nonscientific, they predispose the children to alternative explanatory frameworks that are inhibiting, especially in a knowledge domain such as genetics. In this study, we…

"Hoffman v. Monsanto" raises questions about the civil litigation system. Are courts appropriate institutions, and are class actions the appropriate procedure, for resolving disputes about genetically modified organisms (GMOs)? After addressing the institutional question, this article focuses on procedure. Although class actions are…

Human beings vary in their responses to the drugs prescribed to them. These variations can be due to differences in their age, gender, weight, health status, diet, concurrent therapy and genetic make-up. Recently, it has been estimated that 85% of a patient's response to drugs is due to the genetic make-up of the individual (Snedden, 1999).…

Petroglyphs can help students confront the challenges of cross-cultural interpretation, the "perilous venture" the author and his students will face in their Native American Literature course. Cultural artifacts, carved in rock or printed on paper, are a part of particular discursive systems. In this article, the author wants his…