3 ms·
Yes. And it didn't have to be an all-or-nothing thing. It's also plausible that cow milk was used for babies who lost their mother. So to create an evolutionari
by asymptosis 6y ago
Yes. And it didn't have to be an all-or-nothing thing. It's also plausible that cow milk was used for babies who lost their mother. So to create an evolutionarily significant effect, it was sufficient to simply select for babies who could keep drinking cow's milk for longer and longer, on average.
- thaumasiotes 6y agoYou might be interested to know that there are -- broadly -- three lactase production strategies that humans exhibit. Everyone produces lactase as an infant, for obvious reasons. Some people cease producing lactase at some point in childhood, so that they are unable to digest lactose as adults. Some people continue producing lactase throughout their lives, so that they are always able to digest lactose. But some people continue producing lactase as long as they maintain regular dietary lactose intake, even if that circumstance lasts well into adulthood. However, if they ever go for an extended period without consuming lactose, they permanently cease lactase production.