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Men determine the sex of a baby depending on whether their sperm is carrying an X or Y chromosome.
This would explain why the men that survived the war were more likely to have male children, which resulted in the boy-baby boom.
Boy or girl? It's in the father's genes
In his paper, Mr Gellatly demonstrates that it is likely men carry two different types of allele, which results in three possible combinations in a gene that controls the ratio of X and Y sperm;.
In many of the countries that fought in the World Wars, there was a sudden increase in the number of boys born afterwards.
Description: Journal Reference : Gellatly et al.