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>during a time of scarcity and near-starvation You may not know much about lactation, but nutrition is a big part of it. If there is a famine/drought, there is

>during a time of scarcity and near-starvation You may not know much about lactation, but nutrition is a big part of it. If there is a famine/drought, there is no milk to be had, doesn't matter how strong you may be.

raldi 12y ago
Why do you think lactose intolerance came about, if not as evolution's way to ensure that the available milk went to those who needed it because they were not yet old enough to eat normal food?
- samatman 12y ago
  Producing lactase is costly, those proteins could be doing other things. What's the evolutionary selection pressure to continue digesting a food source that's only present in the infant diet? None.
  - raldi 12y ago
    That's circular reasoning. The only reason it was "only present in the infant diet" is because of the evolution of lactose intolerance. Without that development, children would keep drinking milk for as long as they could get away with it. But don't take my word for it; here's what Slate has to say: "With Cain weaned, Abel could claim more of his mother's attention and all of her milk. This kept a lid on sibling rivalry [...] while allowing women to bear more young." http://www.slate.com/articles/health_and_science/human_evolution/2012/10/evolution_of_lactose_tolerance_why_do_humans_keep_drinking_milk.html http://www.slate.com/articles/health_and_science/human_evolu...
raldi 12y ago
That doesn't appear to be correct; e.g.: "There is a common misconception that malnutrition greatly reduces the amount of milk a mother produces. Although malnutrition may affect the quality of milk, studies show that the amount of breastmilk produced depends mainly on how often and how effectively the baby sucks on the breast. If a mother temporarily produces less milk than the infant needs, the infant responds by suckling more vigorously, more frequently, or longer at each feeding. This stimulates greater milk production." http://rehydrate.org/breastfeed/faq-maternal-nutrition.htm http://rehydrate.org/breastfeed/faq-maternal-nutrition.htm Do you have a citation saying otherwise?
- irishcoffee 12y ago
  No I don't. Perhaps I should do more homework. I was appealing to common sense. If there is a famine or drought, people are starving and thirsty. Making milk is a lot of work and requires at least marginally decent nutrition. If someone is only eating one "meal" a day and drinking 2-4 cups of water a day, there's just not much with which to make milk. N=1 anecdote, my daughters mother was very easily able to tell how her diet affected breastfeeding. A lot of it had to do with water intake.

raldi 12y ago

Why do you think lactose intolerance came about, if not as evolution's way to ensure that the available milk went to those who needed it because they were not yet old enough to eat normal food?

samatman 12y ago
Producing lactase is costly, those proteins could be doing other things. What's the evolutionary selection pressure to continue digesting a food source that's only present in the infant diet? None.
- raldi 12y ago
  That's circular reasoning. The only reason it was "only present in the infant diet" is because of the evolution of lactose intolerance. Without that development, children would keep drinking milk for as long as they could get away with it. But don't take my word for it; here's what Slate has to say: "With Cain weaned, Abel could claim more of his mother's attention and all of her milk. This kept a lid on sibling rivalry [...] while allowing women to bear more young." http://www.slate.com/articles/health_and_science/human_evolution/2012/10/evolution_of_lactose_tolerance_why_do_humans_keep_drinking_milk.html http://www.slate.com/articles/health_and_science/human_evolu...

raldi 12y ago

That doesn't appear to be correct; e.g.: "There is a common misconception that malnutrition greatly reduces the amount of milk a mother produces. Although malnutrition may affect the quality of milk, studies show that the amount of breastmilk produced depends mainly on how often and how effectively the baby sucks on the breast. If a mother temporarily produces less milk than the infant needs, the infant responds by suckling more vigorously, more frequently, or longer at each feeding. This stimulates greater milk production." http://rehydrate.org/breastfeed/faq-maternal-nutrition.htm http://rehydrate.org/breastfeed/faq-maternal-nutrition.htm Do you have a citation saying otherwise?

irishcoffee 12y ago
No I don't. Perhaps I should do more homework. I was appealing to common sense. If there is a famine or drought, people are starving and thirsty. Making milk is a lot of work and requires at least marginally decent nutrition. If someone is only eating one "meal" a day and drinking 2-4 cups of water a day, there's just not much with which to make milk. N=1 anecdote, my daughters mother was very easily able to tell how her diet affected breastfeeding. A lot of it had to do with water intake.