Sex reversal is the phenomenon whereby organisms developing at sex-specific temperatures hatch the opposite sex. This can be caused by human pollutants, including herbicides, which can act as estrogen promoters or inhibitors, which would respectively increase or decrease the number of female offspring, through controlling aromatase. However, much is still unknown about temperature-dependent sex determination, so the exact mechanism for sex reversal is unknown.
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Sex reversal Wikipedia(Text) CC BY-SA