Evolution: rationalism versus creationism

The actual neo-Darwinian concepts of human evolution conceive this evolution as a bush, unpredictable and at random. At the beginning of the 20th century, most of the biologists conceived evolution as a linear process oriented to progress, even if Darwin already presented evolution as a bush. It is this point of view, of a process in one dimension, that some Catholics, for instance, still see human evolution. One accepts with more difficulty that human evolution constitutes, as for all animal species, a bush where numerous abortive branches are present. The evolution does not correspond to any creator myths of the different religions: these myths are parts of the memes, from which the "reproductive success" is regularly decreasing, they keep only some allegoric value (AU)

Les concepts néo-Darwiniens actuels de l’évolution humaine conçoivent cette évolution comme un buisson, non‐prédictible et aléatoire. Au début du 20ème siècle, beaucoup de biologistes concevaient l’évolution comme un processus linéaire orienté vers le progrès. C’est par ce point de vue, de processus à une dimension, que certains Catholiques, par exemple, voient toujours l’évolution humaine. On accepte avec plus de difficulté que l’évolution humaine constitue, comme pour toutes les espèces animales, un buisson où de nombreuses branches abortives sont présentes. L’évolution ne correspond pas aux mythes créateurs des différentes religions: ces mythes sont des mèmes, dont le “succès reproductif” diminue régulièrement, ils gardent uniquement une valeur allégorique (AU)

Genetic contribution to variation in body configuration in Belgian nuclear families: a closer look at body lengths and circumferences.

The purpose of the current study was to evaluate the contribution of genetic factors on body configuration related phenotypes. The sample consisted of 119 Belgian nuclear families including 231 males and 229 females. Factor analysis with varimax rotation was carried out to analyse 13 length and circumference measures and the resulting two synthetic traits (LF and CF; linear and circumference factors, respectively) were used as summary variables. Univariate quantitative genetic analysis indicated that variation in anthropometric as well as in synthetic traits was significantly dependent on additive genetic effects, with heritabilities ranging from 0.55 to 0.88. Narrow sense heritability estimates were higher for measurements principally characterizing skeletal mass than in variables that also involve soft-tissues. Sex, age and their interactions explained 11-67% of the total phenotypic variance. This report also examined the covariations between pairs of anthropometric and synthetic traits (length measurements and LF vs. height; circumference measures and CF vs. weight and BMI; LF vs. CF). Significant genetic correlations among all the studied traits (except for middle finger length vs. height) confirmed the influence of pleiotropy on genetic determination of these phenotypes. Bivariate analysis showed that pleiotropic effects had a great influence in determining body traits variation within body length measurements, as well as between body circumferences and weight or BMI. In relation to the two synthetic traits, even the variation of body lengths and circumferences was highly determined by genetic factors, shared genetic influences were unlikely to explain much of the observed variation between LF and CF. The results of the present study allow us to conclude that in this population body configuration related traits are subject to a strong genetic control and that shared genes also contribute to this genetic structure.

Common genetic and environmental factors among craniofacial traits in Belgian nuclear families: comparing skeletal and soft-tissue related phenotypes.

The major objective of this study was to determine the possible effects of common genetic and environmental factors among 18 craniofacial anthropometric traits, with special attention to the differences between skeletal and soft-tissue related phenotypes. The studied sample consisted of 122 nuclear families living in Brussels and included 251 males and 258 females aged from 13 to 72 years. Univariate and bivariate quantitative genetic analyses were performed using a variance components procedure implemented in SOLAR software. All phenotypes were significantly influenced by additive genetic factors with heritability estimates ranging from 0.46 (nose height) to 0.72 (external biocular breadth). Sex, age and their interactions explained 7-46% of the total phenotypic variance of the traits. Bivariate analysis revealed that several traits share a common genetic and/or environmental basis while other traits show genetic and environmental independence from one another. More and greater genetic and environmental correlations were observed among skeletal phenotypes, than among soft-tissue traits and between both categories. Apart from the tissue composition, other characteristics of the craniofacial morphology such as the orientation (e.g. heights, breadths) have shown to be important factors in determining pleiotropy and common environmental effects between some pairs of traits. In conclusion, the results confirm that overall head configuration is largely determined by additive genetic effects, and that common genetic and environmental factors affecting craniofacial size and shape are stronger for the skeletal traits than for the soft-tissue traits.

Growth and nutritional status in children and adolescents with cystic fibrosis.

BACKGROUND: Growth retardation, delayed puberty and malnutrition are frequently observed in children suffering from cystic fibrosis. AIM: The aim of this study was to estimate growth and nutritional status in children with cystic fibrosis on the basis of body proportions and body mass index. SUBJECTS AND METHODS: Anthropometric data were collected from the medical histories of 62 patients treated in three cystic fibrosis treatment centers in Poland. Anthropometric parameters were expressed in terms of standard deviations away from age-specific and sex-specific reference means reported for the population of Poland. Two-way analysis of variance was used to determine whether the type of cystic fibrosis transmembrane conductance regulator (CFTR) mutation is correlated with age at the time of diagnosis and with body proportions. RESULTS: The type of mutation was significantly correlated with height, weight and transverse chest width. Growth retardation was greater in subjects diagnosed before they were 3 years old than in subjects diagnosed later. The children had infantile body proportions. Their legs were short and their trunks were long in comparison to their height. Almost 40% of the subjects suffered from malnourishment. CONCLUSION: Further study is needed to determine how growth in children with cystic fibrosis is affected by clinical practice and socio-economic factors.

Contribution of genetics and environment to craniofacial anthropometric phenotypes in Belgian nuclear families.

In this study we estimate relative genetic and environmental influences on head-related anthropometric phenotypes. The subject group consisted of 119 nuclear families living in Brussels, Belgium, and included 238 males and 236 females, ages 17 to 72 years. Two factor analyses with varimax rotation (the first one related to facial measurements and the second one to overall head morphology) were used to analyze 14 craniofacial size traits. The resulting four synthetic traits [HFCF, VFCF, HDF1, and HDF2-horizontal (breadth) and vertical (height) facial factors and two head horizontal (breadth) factors, respectively] were used as summary variables. Maximum heritabilities (H2) were estimated for all studied traits, and variance components analysis was applied to determine the contribution of genetics and environment on the four craniofacial factors. In addition, we examined the covariations between the face (HFCF and VFCF) and head-related factors (HDF1 and HDF2), separately. Quantitative genetic analysis showed that HFCF, VFCF, HDF1, and HDF2 variation was appreciably attributable to additive genetic effects, with heritability (h2) estimates of 67.62%, 54.97%, 70.76%, and 65.05%, respectively. The three variance components reflecting a shared familial environment were nonsignificant for these four phenotypes. Bivariate analysis revealed significant additive and residual correlations for both pair of traits. The results confirm the existence of a significant genetic component determining the four craniofacial synthetic traits, and common genetic and environmental effects shared by the two face-related phenotypes and by the head-related ones.

Growth of children living in the outskirts of Ankara: impact of low socio-economic status.

BACKGROUND: Most studies of the growth of Turkish schoolchildren are limited to large cities and to subjects from high socio-economic background. Very little is known about growth and development of rural, suburban and low socio-economic children in Turkey. AIM: The purpose of this study is to compare height and weight of school-aged children of low socio-economic background with available growth data from high socio-economic strata, and to verify the possible influences of three socio-demographic parameters on their growth. SUBJECTS AND METHODS: The sample consisted of 1,052 girls and 1,223 boys, aged between 7-17 years, living in the outskirts of Ankara, a suburban area of poor socio-economic background. Centile distributions for height and weight were estimated by the LMS-method. ANOVA and Student's t-test were used to compare mean z-scores for height and weight among the various categories of the socio-demographic parameters. RESULTS: Children living in the outskirts of Ankara have lower mean values for height and weight when compared with growth data of upper socio-economic strata children. The differences were most pronounced during adolescence. Skinfolds were higher in girls than in boys at all ages (largest p = 0.007). There was no clear relationship between growth and the number of siblings, the number of rooms in the house, the mother's and father's education, and the father's professional status (p > 0.05), except for the height of girls (p < 0.05). CONCLUSION: It is suggested that the lower growth status of children living in the outskirts of Ankara is attributable to the poor socio-economic status of this suburban population, which has not changed over the past decades. It is postulated that the growth impairment during adolescence might be due to a reduced tempo of growth in these children.

What challenges offers nanotechnology to bioethics?

Aunque la ciencia significa hoy en día el progreso, para algunas personas supone moralmente un peligro. Sin embargo, el progreso no debe de ser suprimido, y en todo caso, debería ser controlado. Estos autores sostienen que la ciencia y la moral están estrechamente unidos y se complementan entre sí. Es decir, la tecnología, la sociedad y la moral por separado no tienen la verdad absoluta y se deben de complementar entre sí sin que ninguno de los tres sea suprimido (AU)

Though nowadays science means progress, for some people it means a moral danger. However, the progress should not be suppressed, and in every case, it should be controlled. These authors uphold that science and morality are closely linked and complementary. That is, technology, society and morality, by themselves, do not have the absolute truth and must be complemented among them without any of the three being suppressed (AU)

What challenges offers nanotechnology to bioethics?

Though nowadays science means progress, for some people it means a moral danger. However, the progress should not be suppressed, and in every case, it should be controlled. These authors uphold that science and morality are closely linked and complementary. That is, technology, society and morality, by themselves, do not have the absolute truth and must be complemented among them without any of the three being suppressed.

Comparative genetic variance and heritability of head and facial traits in northwest Indian and Belgian twins.

Genetic variance analysis of 13 head and facial traits is considered in samples of Northwest, Indian and Belgian twins. Modified t tests, based on the nested structure of twin data, indicate differences between monozygotic (MZ) and dizygotic (DZ) mean values of bigonial diameter in Indian females and in Belgian males, i.e., for only two of 52 instances. Heterogeneity of variance is observed in about 30% of the craniofacial traits in both samples, invalidating conventional within-pair genetic variance estimates for these traits. Patterns of environmental bias on zygosities differ between sexes within the same population and also between the two samples. Revised average genetic variance ratios are higher in Indian than in Belgian twins. Male twins manifest, on average, higher genetic variance ratios than female twins in both the samples. There is stronger evidence of enviornmental covariance in MZ than in DZ twins for both Indian and Belgian twins. The pattern of intraclass corrlations, based on average values, is as follows: ♂rMZ > ♀rMZ > ♂rDZ ≥ ♀rDZ in the Indian twins and ♂rMZ > ♀rMZ > ♀rDZ > ♂rDZ in the Belgian twins.