Data from 236 pairs of black twins and white twins aged 13-17 years were used to examine genetic and environmental factors influencing cranial size, an indirect estimate of brain volume. Genetic factors are required to account for the phenotypic variance in cranial capacity. (SLD)

The relationship between mental retardation and brain size is discussed. Research suggests that a common path for many otherwise idiopathic mild retardation cases (genetic or environmental) could be small brain size, indicating reduced information processing capacity. Suggestions are made for further research on neuron number. (SLD)

Studies of families, twins, and adoptees support a genetic predisposition to alcoholism. Alcohol metabolism may affect the regulation of alcohol intake, because interference with production or elimination of the alcohol metabolite acetaldehyde has behavioral effects. Ongoing research is examining individual and tribal differences in alcohol…

This case study describes a 12-year-old boy with autism in association with the folate-sensitive fragile site fra(2)(q13). Cytogenetic results of blood analysis are described, and two possibilities are discussed: the fragile site may be a coincidental finding unrelated to the autism, or may represent an area of potential gene damage. (JDD)

Discusses ecological, social, and moral issues associated with destruction of rural communities, industrial agriculture, gene patenting and international trade. Analyzes agricultural ramifications of the Common Agriculture Policy (CAP) and the General Agreement on Tariffs and Trade. Cites these and other measures as the struggle of industrialized…

Presents four misconceptions students have concerning the concepts of recessive and dominant alleles. Discusses the spectrum of dominant-recessive relationships, different levels of analysis between phenotype and genotype, possible causes of dominance, and an example involving wrinkled peas. (MDH)

Fifty-seven same-sex twin sets (32 monozygotic and 25 dizygotic) were examined for concordance of speech and language disorders. Monozygotic twins had a higher concordance than dizygotic twins and also were more similar in the types of disorders they presented than dizygotic twins. Positive family histories were reported for both groups.…

The methodology of many studies that have identified specific genetic loci for disorders associated with mental retardation is criticized as failing to demonstrate an association between the behavior phenotype and the genetic marker. A more appropriate methodology using a multitrait-multimethod approach is suggested. (Author/JDD)

Outlines some of the current scientific and educational issues related to behavioral genetics and recommends using behavior as a vehicle to improve the teaching of genetics at the high school level. Contains 77 references. (DDR)

Describes the successful use of giving examples of genes affecting various steps in biochemical pathways to teach gene interaction. Finds that once students grasp the notion that genes can interact because they control different steps within biochemical pathways, the reason why phenotypic ratios appear to be non-Mendelian becomes more obvious and…

Used prospective data to examine the relationship between the family environment and child and adolescent achievement and to determine genetic and environmental contributions to this relationship. Data from 2,108 sibling full- and half-sibling pairs from the National Longitudinal Survey of Youth suggest that genetic factors explain about…

Argues that Darwinian evolution provides a framework for understanding how a polymer such as RNA might have arisen and perpetuated itself in a changing environment. Also explains how one genetic system invents another. (DDR)

Recommends the use of ethical issues to engage college nonscience majors in discussion. Focuses on using problems that pertain to biomedical situations and decisions such as transferring living parts from one type of organism into another. (DDR)

Proposes models for the lichen symbiosis, genomic, and plasmid DNA and fluid mosaic membrane structure. The models operate at the classroom level with the classroom becoming the cell in a DNA exercise with students as interactive components. (DDR)

Attempts to show how genes and environments cooperate in the construction of organisms, focusing on how genes require environmental and behavioral inputs to function appropriately during the normal course of human development. The discussion is related to a model of probabilistic epigenesis. (SLD)