Taxonomic surrogacy in biodiversity assessments, and the meaning of Linnaean ranks

Copyright © 2006 The Natural History MuseumThe majority of biodiversity assessments use species as the base unit. Recently, a series of studies have suggested replacing numbers of species with higher ranked taxa (genera, families, etc.); a method known as taxonomic surrogacy that has an important potential to save time and resources in assesments of biological diversity. We examine the relationships between taxa and ranks, and suggest that species/higher taxon exchanges are founded on misconceptions about the properties of Linnaean classification. Rank allocations in current classifications constitute a heterogeneous mixture of various historical and contemporary views. Even if all taxa were monophyletic, those referred to the same rank would simply denote separate clades without further equivalence. We conclude that they are no more comparable than any other, non-nested taxa, such as, for example, the genus Rattus and the phylum Arthropoda, and that taxonomic surrogacy lacks justification. These problems are also illustrated with data of polychaetous annelid worms from a broad-scale study of benthic biodiversity and species distributions in the Irish Sea. A recent consensus phylogeny for polychaetes is used to provide three different family-level classifications of polychaetes. We use families as a surrogate for species, and present Shannon–Wiener diversity indices for the different sites and the three different classifications, showing how the diversity measures rely on subjective rank allocations.Y. Bertrand, F. Pleijel and G. W. Rous

<a name="top"></a>Antropometria de atletas culturistas em relação à referência populacional Anthropometry of body builders in relation to the population standard

Atletas de culturismo têm como alvo de treinamento a hipertrofia muscular e a redução da adiposidade. A falta de referências antropométricas apropriadas pode levar esses indivíduos a serem erroneamente considerados em situação de sobrepeso ou desnutrição. Portanto, objetivamos comparar a composição corporal de atletas de culturismo com os padrões populacionais. Foram avaliados 36 atletas, de ambos os sexos, 26 do sexo masculino (27,2 ± 7,2 anos) e 10 do sexo feminino (30,0 ± 6,1 anos), por ocasião da competição nacional, quanto aos indicadores antropométricos de peso, estatura, índice de massa corpórea, pregas cutâneas, adiposidade corpórea e circunferência muscular do braço. Os resultados foram referidos quanto à posição percentual ou de desvios-padrão (pelo escore Z) tendo como referências padrões populacionais locais. Como resultado, encontramos que os indicadores com menor contraste com os padrões adotados foram peso e estatura e os maiores contrastes foram encontrados na circunferência muscular do braço para os homens, e pregas cutâneas tricipital para as mulheres. Pelo indicador muscular todos foram classificados como obesos ou sobrepeso, enquanto que pela prega cutânea tricipital e adiposidade corpórea, a desnutrição esteve presente em 100,0% das mulheres e 88,5% dos homens. Fica evidenciada a inadequação da utilização do padrão antropométrico populacional para a classificação nutricional de atletas de força, em particular culturistas, sendo assim necessário o estabelecimento de padrões próprios para esse tipo de treinamento (modalidade).<br>Body builders have as their training goals the maximum muscle hypertrophy with minimum adiposity. However, the scarcity of specific standards implies often in framing wrongly those athletes either as overweight (by their BMI) or energy malnourished (by their fat stores). The objective of this study was to compare the body composition of body builders with population standards. Thirty-six adults, 26 male (27.2 ± 7.2 years) and 10 female (30 ± 6.1 years) nationwide competitive body builders, were assessed considering weight, height, body mass index, adiposity, arm and leg circumferences and skinfolds. The data were referred either as percentile or standard deviations (Z score) of population standards. Body weight and height were among the closest values from the populational mean whereas upper arm muscle circumference (for men) and body adiposity (for women) were the farterest. By using fat parameters as indicators of their protein-energy status, the undernourishment was found in 88.5% of men and 100.0% of women. Thus, it seems that body builders deserve their own anthropometric standards to avoid nutritional status misplacements