Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pm
But it is overly simplistic to just say that sometimes evolution is faster. Two factors contribute to evolution: mutation and natural selection.
A beneficial mutation can also be lost if there's not enough pressure for it, due to the randomness of sexual reproduction. Evolution is fast when there's more pressure, that isn't to say there's not still a speed-limit.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmSo was there enough genetic variability in the protodog population to allow an herbivorous dog to emerge, or similarly to turn us from frugivores into whatever it is that eats beans? Maybe.
Given we have yo-yoed between vastly different diets as need arose, it is evolutionarily advantageous to keep those genes around. Given how fast dogs and other species adapt to new diets, there's no reason to believe humans are any different.
When we did eat fruit, we didn't eat it for very long; no reason to believe there were any more than modest adaptations to it that didn't significantly harm our ability to eat other foods (like improved color vision, perhaps). We never specialized for it in a substantial way. Certainly much less than dogs specialized as carnivores, and yet contemporary dogs are healthier on plant based diets.
You could argue that, even for a carnivore, plants are inherently more healthy as a source of nutrition for a number of reasons -- I think you'd be right, but you'd be appealing to modern evidence and not making an evolutionary appeal. The same kind of evidence tells us how healthy veggies and beans are.
I went over the claims against beans elsewhere.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmHas there been enough time since the dawn of agriculture to mutate new genes to metabolize all these things better than we could before? 10,000 years? I doubt it, that's a drop in the bucket.
We already had those genes. Phytates, for example, are widely occurring in plants (not just beans, they're just more concentrated) and there was never a period where we didn't eat greens, except perhaps brief periods of carnivory.
Given how drastically levels reduce with cooking, I don't think we even had to get better at getting around them at all. Chimps and other close relatives are much more challenged by "anti-nutrients" (which are actually good for us anyway, in many ways) than humans are by cooked beans.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmThe argument for evolutionary changes to digest meat are stronger because we have been eating meat a lot longer than we have been farming, but I don't think all those changes overcome certain facts, like our long digestive tract, which is not great for eating meat.
The problem with meat is fundamentally different from the problem of eating a different type of plant (and it applies to carnivores too, regardless of evolution).
Also, cultivation resulted in us changing the plants to better suit us (like lower levels of certain substances), we didn't need to change for things like beans.
The only significant changes involve better adaptation to starches from cooked tubers and grains.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmScience tells us that every chronic disease is like an animal in a zoo we can study and master, and it's such a great thing we now have science to do that. Ideally, it then produces a pharmaceutical to cure every ill. (sorry, that was a low blow, I'm sure you don't promote pharmaceuticals!)
That's not how it works. We're doing a lot of work to look at dietary factors today, and mainstream scientific bodies make recommendations on plant based diets to do just that (not pills).
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmBut the larger truth is that chronic diseases are primarily the consequence of bad diets, regardless of whether you are young or old, that start to emerge later in life only because the immune system and other auto-repair mechanisms are starting to fail.
I addressed the auto-repair bit elsewhere, but the reason we know diet is to blame is science.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmBad diets will still adversely affect younger people, e.g. making them feel tired, getting them sick with colds, etc.
Only very bad diets. Humans are remarkably flexible.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmIf aging could be cured, we could keep eating bad diets for much longer before noticing any ill effects, and could probably do a number of unhealthy things indefinitely and completely cure them along the way. So aging just amplifies the effects of bad diet.
Not really. Things like heart disease actually take a long time to build up; it's not just because you got older but because the plaques had to form.
Cancer is the same way, it's a lottery, not an issue of breakdown in repair mechanisms. Some people lose the lottery as children.
Your understanding of disease is quite off base.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmThat makes sense; it is hard to imagine that a carnivorous diet wouldn't be at least somewhat bad for pets as well, if for no other reason that it is top of the food chain and so highest toxicity and acidity.
Bioaccumulation of toxins is part of it.
There's also the high concentration of methionine (where restriction has been shown to increase longevity in many animals), the high levels of iron which are carcinogenic themselves (heme iron) and facilitate the replication of pathogens, and the fact that when your food is made from the same stuff you are (meat) your microbiome is fine tuned to digest you from the inside out (a disturbing prospect).
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmI've always said that our best hope of saving the planet is to destroy it as quickly as possible. I say this tongue in cheek, but what I mean is that people won't take strong enough action until they see real cataclysms.
That might be true. Hopefully we can get a wake up call before it's too late.
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmThe green revolution feeds the planet, but at the cost of killing it.
How is that?
Steve Wagar wrote: ↑Fri Sep 01, 2017 6:50 pmAnd in vitro meat may be available in ten years, but will still cause chronic disease.
True, but at least we'll be around to get sick.