For Some Mammals, Large Adult Daughters, Not Sons, Are the Norm

Female elephant seals are not delicate creatures. They are rippling tubes of muscle and blubber that can weigh more than 1,000 pounds. Still, female elephant seals are absolutely dwarfed by their male counterparts, which are typically at least three times heavier.It is an extreme case of what is known as sexual size dimorphism, and one that fits within a longstanding narrative that male mammals tend to be larger…