The two great modern naturalists, Linnaeus and Darwin, expressed their intuition about how best to visualize patterns of affinities, that is, morphological similarities and divergences between taxa. Linnaeus suggested that "all plants show affinities on all sides, like a territory on a geographical map," while Darwin thought that it was virtually impossible to understand the affinities between living and extinct species without a genealogical tree. Genealogical trees follow the diachronic, evolving logic of a timeline, whereas maps depict a synchronous pattern of extant taxa.
View Article and Find Full Text PDFThe sole diagram in On the Origin of Species is generally considered to be merely an illustration of Darwin's ideas, but such an interpretation ignores the fact that Darwin himself expressly stated that the diagram helped him to discover and express his ideas. This article demonstrates that developing the so-called "tree diagram" substantially aided Darwin's heuristics. This demonstration is based on an interpretation of the diagram and of 17 sketches found in Darwin's scientific papers.
View Article and Find Full Text PDFThe main aim of the present study was to test Rogers' theory, stating that parental styles characterized by unconditional positive regard (UPR) promote healthier adults than parental styles characterized by conditional regard (CR). For both caregivers CR was found to be associated with significantly higher scores on psychological complaints than UPR (on nearly all SCL-90 scales and the SCL-total score), even when controlling for gender. Although lack of emotional warmth by the father and harsh discipline by the mother were significant predictors of SCL-90-Total (indicating state neuroticism) it should be noted that both variables only explained a small amount of the total variance.
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