Body Size Growth Research Articles

Growth in Body Size: A Compendium of Findings on Contemporary Children Living in Different Parts of the World

This chapter focuses on somatic development during the segment of human ontogeny between birth and the beginning of adolescence. From studies across the globe, findings are assembled for groups of infants and children measured largely between 1950 and 1965. Body weight and stature are investigated widely. Other variables, including head girth, sitting height, chest girth, shoulder width, hip width, arm girth, and calf girth are also discussed. The chapter serves a threefold function: It colligates quantities of knowledge currently scattered in scientific journals, books, monographs, and unpublished documents; it provides composite statistics able to support more substantial and precise inferences than the statistics available in the piecemeal reports; and it yields new generalizations through the alignment and intercomparison of results.

Childhood retardation resulting in reduction of adult body size due to lesser adolescent skeletal delay

AbstractThe skeletal maturation of 7972 rural children from the six Central American nations, aged one month through 22 years, is evaluated. The results suggest that retardation in skeletal maturation during childhood is significantly greater than during adolescence, while growth in body size shows a progressive delay from infancy through adolescence. In other words, the apparent improvement in skeletal maturation during adolescence is not associated with an equivalent “catch‐up” in body size. Similarly, prolongation of the period of growth does not fully compensate for the slow rate of growth. It is postulated that the small stature in Central America is related to the marked childhood retardation and to the fact that during adolescence, the timing of skeletal maturation is less affected than growth in size.

Altitude and growth: a study of the patterns of physical growth of a high altitude Peruvian Quechua population.

AbstractData on physical growth were obtained for a sample of 1202 Quechua subjects, aged 2 to 35 years from the district of Nuñoa, Puno, located in the southern highlands (altitude 4000–5500m) of Peru. These data were supplemented by a three‐year longitudinal study of 300 subjects, aged 1 to 22 years.The patterns of physical growth of members of the indigenous population of Nuñoa are characterized by (1) late sexual dimorphism, (2) slow and prolonged growth in body size, (3) late and poorly defined adolescent stature spurt in both males and females, and (4) accelerated development in chest size. The socio‐economic factors associated with urban‐rural and altitude differences appear to be reflected in greater deposition of subcutaneous fat and increased weight but do not seem to influence the development of stature. We suggest the pattern of growth of this population is related to the hypoxic effects of high altitude, and/or reflects a genetic adaptation to such stress. The anthropometric and physiological studies conducted during this and previous studies and the comparative data from Peruvian populations situated at lower altitudes document the specific adaptive response of the chest wall to the hypoxic effects of high altitude.

The lack of evidence for co-adaptation in crosses between geographical races ofDrosophila subobscuraColl.

1. The paper described an attempt to see whether differences in co-adaptation between populations ofDrosophila subobscuraare related to the distance between them. The mean and the variance of body-size, development time and survival were recorded on parent populations and the F1and F2of various crosses to test for heterosis in the F1and decline in performance or greater variance in the F2, which might indicate the break-up of co-adapted gene arrays. Comparisons were carried out at different temperatures and on a variety of larval diets, especially sub-optimal ones in which the larvae were grown on synthetic media. A large number of wild flies were caught at sites separated by about 10 miles along a transect of southern Scotland; these comprised one series of comparisons. For more distant crosses flies were caught at sites in southern England, Denmark, Switzerland and Israel.2. There were well-defined differences in body-size, and, to a lesser degree, development time between populations from more widely separated localities and these showed evidence of a cline, northern populations having larger body-size. The difference in size between the Scottish and Isreal populations is about 20%.3. There was no evidence of differences in co-adaptation between populations even in crosses between populations from sites as far apart as Scotland and Israel. The F1's were always close to the mid-parent values and there was no evidence of breakdown in the F2nor of increased variability.4. There was hardly any evidence of gene-environment interaction either with respect to different diets or to different temperatures.5. Records of body-size on flies caught in the wild showed that they are extremely variable, indicating great variation in larval nutrition. Under natural condition stability of growth in body-size is conspicuously lacking in this species.6. An additional test of co-adaptation was based on the between-family variance of abdominal bristle number of intra- and inter-population matings in the two most widely separated populations. There was no evidence of greater variance in the inter-population series.7. To test for possible differences in breeding structure, the response to inbreeding was determined for two widely separated populations ofD. subobscuraand a long-established cage population ofD. melanogaster, on an unrestricted larval diet and also on several different kinds of sub-optimal diets. There was little or no sign of consistent differences between the species in their response to inbreeding.8. This test revealed differences between the two species in their minimum requirements for particular nutrients.subobscurais less able thanmelanogasterto withstand lower levels of protein and survival is particularly reduced. On the other hand,melanogasterhas a considerably higher requirement for choline. Where there are apparent differences between the species in the average effect of inbreeding, the inbreeding effect is greater on the relatively more sub-optimal diet.9. Comparison of the performance of the immediate descendants of wild flies with those derived from the same site, but kept in the laboratory for some twenty generations, failed to show any differences on several different diets and so there was no evidence that adaptation to laboratory conditions was important.10. The lack of evidence for co-adaptation apparently conflicts with what has been claimed for other species. Such differences are discussed.

GROWTH AND VARIABILITY IN DAPHNIA PULEX

Eighty-two individually reared female Daphnia pulex were observed from the time they were released from the brood chamber of their mothers until they died. Measurements of total length, carapace length, and height were made daily on each animal. The number of young released during each instar was recorded.Seventy-one animals were primiparous during the fifth instar and 9 during the sixth. Consequently the number of pre-adult instars is variable, the minimum being four.Data from the 47 animals which were primiparous during the fifth instar and which lived for twenty instars or more were used in constructing growth curves. Growth in the three dimensions studied is sigmoid. The point of inflection in all curves comes during the fourth instar, the last pre-adult.The Robertson and the Gompertz equations do not fit the data satisfactorily. This may be due to the time unit employed, which in this case is the instar.The growth increment is greatest during the fourth instar. The increments increase up to the fourth instar, then decrease gradually until the eleventh instar, after which they remain low and relatively constant.A significant negative correlation exists between initial body size and initial growth rate, also between duration of growth and final body size. Other characteristics of the growth process investigated appear to vary independently.The number of young released during the adult instars increases to a maximum at the tenth instar followed by a gradual decrease.The number of young released during any adult instar is significantly correlated with the growth increment for the instar preceding the one during which the young are released.Relative growth in the dimensions studied may be expressed satisfactorily by the equationy = bxα.No marked changes occur in the relations between total length and carapace length. Marked changes in the relations between carapace length and height and between total length and height occur at the thirteenth instar.The standard deviation and coefficient of variation of total length tend to increase somewhat during the early instars, but after the eighth instar both decrease rather steadily.Relative variability in body size, as measured by the coefficient of variation of total length, is roughly directly proportional to the logarithm of the growth rate. The existence of this relationship is ascribed largely to the mode of action of environmental factors during growth. It may perhaps also be explicable in terms of Rahn's theory of the physico-chemical origin of variability in growth rate.Size-frequency analyses of natural populations as methods of studying growth are shown to be inferior to the method using individually reared animals.