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People have burned peat or used lead for centuries, which is horrible for your health. Just because humans have had something in the environment historically do
by kritiko 5y ago
People have burned peat or used lead for centuries, which is horrible for your health. Just because humans have had something in the environment historically doesn't mean it's safe.
- forgotmypw17 5y agoI had a different scale in mind. I'm not talking about "historically", but "evolutionarily", so on the order of millions of years, not hundreds.
- abainbridge 5y agoI don't think centuries is long enough. We don't seem to have finished evolving our coping strategies for alcohol and lactose and it is probably 20,000 years since those were added to our environment. And in both cases, we already had a head start - there has been trace amounts of alcohol in overripe fruit and lactose in breast milk, basically forever.
- faeyanpiraat 5y agoHavent rotten fruits been around since forever? Our evolutionary ancestors could’ve involuntarily consumed alcohol way before 20k BC.
- checkyoursudo 5y agoInvoluntarily on 1 Jan 20,000 BC, but voluntarily ever since 2 Jan 20,000 BC.
- kube-system 5y agoEvolution only corrects as much as is required for reproduction; and as far as reproduction is concerned, avoidance is just as good of a response as tolerance. Humans have evolved to cope with lactose and alcohol. Getting sick is that response. This is the same in how we've evolved to live with fire. Not because evolution can magically make us invincible to chemical combustion -- instead we have pain receptors and learn to avoid it.
- tsimionescu 5y agoA minor quibble, though I agree with your point overall: lactose intolerance is not an adaptive response to something harmful in lactose (the way getting sick from alcohol is), it's more of an efficiency hack: since mammals normally only consume lactose as babies, our bodies stop producing the lactase enzyme around the time we stop breast-feeding, so we stop being able to digest this type of sugar, which we would normally never encounter again (or no more than trace amounts). Some 20k years ago, some of our ancestors started consuming milk even in adulthood, and it turned out a few of them had a mutation that allowed them to continue producing lactase even in adulthood. Since milk is actually a very nutritious substance if you can farm it, these people thrived and passed on their genes, in some areas.
- kube-system 5y agoThat's a good point. I was thinking more generally: "someone drinks milk, they get sick, they don't drink it, don't die".
- tsimionescu 5y agoYes, but it's interesting to contrast with alcohol sickness. The reason people without lactase get sick from lactose is because the lactose passes most of their digestive tract intact, and is then broken down by bacteria in their intestines, releasing gas, causing mechanical pressures on their intestines that are perceived as pain and other symptoms. In the case of alcohol, our body detects the alck of balance and other neural impacts, classifies this as a poisoning, and it tries to provoke vomiting to eliminate as much as possible of the poison. It's explicitly an adaptive response that we developed to survive consumption of poisonous substances.
- deleted 5y ago[deleted]
- kube-system 5y agoIt's a different biological means to the same evolutionary ends. Maybe the additional involuntary processes associated with alcohol were evolutionarily necessary because humans also experience other feelings which induce the consumption of alcohol. I mean, milk is fine, but we don't call it happy-hour when we drink milk. :)