EVOLUTION OF SEX:
A Genomic Battle of the Sexes
Elizabeth Pennisi
Organisms wield a genetic weapon in the battle of the sexes: genomic imprinting, in which genes from one parent are marked for later silencing or disposal. Because in mammals the developing fetus is a virtual parasite on the mother, mammalian researchers argue that imprinting represents a battle over the growth rate of the fetus and have new data from studies in mice to support their case. In addition, new data from plants are further bolstering the growth-rate hypothesis.