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Early field studies in human nutrition documented the eating habits of African Americans living in a variety of circumstances. We compare the results of these investigations. Our analysis shows systematic differences along a continuum reaching from remote, rural communities in the South toward increasingly metropolitan locations. On the latter end of the continuum, we find diets richer in protein, composed of a wider variety of foods and containing fewer of what we now call "soul foods." Greater market involvement and access to low cost alternatives to more traditional foods help explain these developments.

This article provides a set of codes that rate the starvation and famine experiences of societies in the Standard Cross-Cultural Sample. The codes are used to test several theoretical generaliza tions regarding the underlying cultural causes of famine. The results indicate that several changes arising from world systems involvements increase the likelihood of famine. They suggest fur ther that the extent to which societies experience famine depends on cultural definitions of property and exchange rights. In addition, results confirm the understanding that famine is especially prone to break out in environments of chronic hunger and recurrent starvation.

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Cytoplasmic effects on plant performance have been documented, but are not well understood. Cucumber (Cucumis sativus) is a useful plant for studying organellar effects on phenotypes because chloroplasts show maternal transmission and mitochondria paternal transmission. We produced doubled haploids (DH) from divergent cucumber populations, generated reciprocal hybrids in a diallel crossing scheme, measured fresh and dry weights of plants 22–30 days after planting seed, estimated combining abilities and heterosis for early plant growth, and assessed performance differences between reciprocal hybrids with identical nuclear genotypes. Across experiments, general and specific combining abilities and reciprocal effects, as well as their interactions with replicated experiments, were all highly significant (P < 0.001). Hybrids consistently out-performed parental lines with average heterosis over midparent values between 14% and 30%. A mitochondrial mutant (MSC3) showed negative effects when used as the male due to paternal transmission of mitochondria, but not as the female parent. Reciprocal hybrids among wild-type DH parents were identified that differed significantly (P = 0.032 to 0.001) for dry and fresh weights across experiments, indicating that cucumber breeders should evaluate both directions of crosses when producing hybrid cultivars. Reciprocal hybrids from DH cucumbers offer a unique opportunity to study biological factors contributing to significantly better performances, due to specific nuclear-cytoplasmic combinations and/or parent-of-origin effects in identical nuclear backgrounds.