Variation of human sex ratios at birth by the sex combinations of the existing sibs, and by reproductive stopping rules : answer to comments by William H. James.
We thank Dr James for his always stimulating comments on variations in the sex ratio at birth.
Dr James makes some specific comments and queries about our interpretation of the Lexis variations that we found in data from both Europe and Africa.
These Lexis variations (different probability of bearing a boy among couples) were shown primarily by a statistical analysis of the distribution of boys and girls according to the number of males and female already born in the family (Garenne, 2008b, 2009a).
In another paper, we showed Poisson variations by age of mother and birth order using the same African data (Garenne, 2008b).
We fully agree with Dr James that any systematic Poisson variation will have only a minor effect on the variance of the distribution of boys and girls in families.
We have also addressed the issue of behavioural factors in a comment to a study based on American data (Garenne, 2009b).
Mots-clés Pascal : Variation, Homme, Sex ratio, Naissance, Sexe, Reproduction, Etude critique, Sociobiologie
Mots-clés Pascal anglais : Variations, Human, Sex ratio, Birth, Sex, Reproduction, Critical study, Sociobiology
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 11-0449167
Code Inist : 002B30A11. Creation : 12/12/2011.