30 MAY 2012 by ideonexus
Humans are Nothing Special
Asian Homo erectus died without issue and does not enter our immediate ancestry (for we evolved from African populations); Neanderthal people were collateral cousins, perhaps already living in Europe while we emerged in Africa... In other words, we are an improbable and fragile entity, fortunately successful after precarious beginnings as a small population in Africa, not the predictable end result of a global tendency. We are a thing, an item of history, not an embodiment of general principl...Folksonomies: evolution
Folksonomies: evolution
"We are a thing, an item of history, not an embodiment of general principles."
21 SEP 2011 by ideonexus
Evolution of Lactose Tolerance
One case involves our ability to digest lactose, a sugar found in milk.
An enzyme called lactase breaks down this sugar into the more easily
absorbed sugars glucose and galactose. We are born with the ability to
digest milk, of course, for that’s always been the main food of infants.
But after we’re weaned, we gradually stop producing lactase. Eventually,
many of us entirely lose our ability to digest lactose, becoming “lactose
intolerant” and prone to diarrhea, bloating, and cramps a...Some groups of humans evolved the ability to digest milk beyond infancy as their societies domesticated cows.