(Not a teacher)
The author is suggesting that life today is as perilous in some ways as it was for our remote ancestors, and that we must keep something in reserve. Just as the ancients kept dried mammoth (mammoth jerky) for use in lean times, so must we maintain reserves (financial, foodstuffs, etc.).
When women have more say in running the world, says the writer, some men will still be useful, as, for example, in helping to lift heavy objects down off the shelf (no doubt a reference to the mammoth meat).
I hope this answered your questions.