I wonder why an apple should be healthy. Wouldn’t any animal be satisfied with a fruit that just had calories? Enough, in any case, to come back for more and scatter the seeds? Why should an apple—or anything ‘natural’—be so especially healthy for humans?
You’re missing the other side of the story. Humans evolved to obtain their nutritional needs from those foods that were available in the EEA and this effect is probably more significant than the selection pressure in the other direction (on fruits to be nutritionally beneficial to animals that eat them). Humans are adapted to a diet that includes things that were available to them during the long pre-agricultural evolutionary period.
OK. So reading between the lines somewhat and pushing the argument further, would it similarly/analogously/generally be the case that eating nearly any part of an evolutionarily ‘old’, highly evolved autotroph would usually be healthy, because they have learned how to make things that are useful for living things to have? (That is, ignoring the part of the argument possibly implying that we might have evolved a dependency upon apples in particular, because that seemed unlikely to me. Though I could be convinced because know it is the case to some degree for oranges and scurvy, for example.)
I don’t think that is correct. Much autotroph biomass is indigestible (think tree trunks) and some of the rest is deliberately poisonous. A clever plant doesn’t want to be eaten. Furthermore, we ought to eat stuff that has good ingredients—we don’t really care whether it makes them itself, or steals them from the manufacturer. And in any case, different living things are built from slightly different kinds of stuff—a lot of autotrophs don’t even bother with vitamins A, C, D, and E.
And finally, try to avoid using the terms “evolutionarily old” and “highly evolved”. Every living thing you see around you is equally “evolved”, since every living thing has the same “evolutionary age”—roughly 3.5 billion years.
I’m not sure that this is at all meaningful because things like selection pressure and mutation rate also arguably matter. If one has a species with lots of generations but an incredibly low mutation rate it isn’t going to adapt to an environment as much as another species in the same environment with a higher mutation rate.
Ok, then. Number of generations. Which makes human among the least evolved of all species on the planet. Well, maybe some tortoises are less evolved than us, and maybe elephants and whales and sequoias too, but we certainly have evolved through fewer generations than rats, jellyfish, mosquitoes, sunflowers, earthworms, amoebae, and E. coli.
And finally, try to avoid using the terms “evolutionarily old” and “highly evolved”.
OK, corrected, thanks. I definitely see the problem with ‘highly evolved’. (For example, a “highly evolved” organism could lose and gain the ability to make a vitamin many times over). I was having trouble separating the ideas of ‘older’ (as in chronologically first) and ‘autotroph’ (as in independent). Animals don’t dependably make the vitamins they need from plants because they can get these vitamins from plants. Plants, though, couldn’t and can’t depend upon something else producing them, so they make them on their own.
Much autotroph biomass is indigestible (think tree trunks) and some of the rest is deliberately poisonous.
Yes, of course. It was sloppy of me not to add the qualifier, ‘if edible’. Instead, what about the validity of this statement: regardless of its edibility, and the amount and type of toxins that might be present, any plant part would be expected to have as many vitamins as a fruit part? The argument being that plants did not have evolutionary pressure to make their fruits particularly full of vitamins?
Furthermore, we ought to eat stuff that has good ingredients—we don’t really care whether it makes them itself, or steals them from the manufacturer.
Agreed. My question is why the former would be healthier. Perhaps because manufacturers sequester more, in greater concentrations?
The argument being that plants did not have evolutionary pressure to make their fruits particularly full of vitamins?
Animals have abilities to detect whether what they eat is nutritious, plants give the animals what they want. That includes things like Vitamin C—though that isn’t an essential nutrient for most animals.
As mattnewport mentioned above our ancestors evolved to live on fruits. Most animals can synthesis their own vitamin C. We only lost that ability because our ancestors had so much of it in their diet that they didn’t need to synthesize it.
If fruits didn’t contain vitamin C, we wouldn’t have lost the ability to synthesize it, possibly losing the ability to synthesize something else that they did have.
… what about the validity of this statement: regardless of its edibility, and the amount and type of toxins that might be present, any plant part would be expected to have as many vitamins as a fruit part?
I don’t see any reason for thinking it would be true. Any plant part should be expected to have as many vitamins as it needs to do what that part of a plant does. Different vegetables are rich in different vitamins.
The argument being that plants did not have evolutionary pressure to make their fruits particularly full of vitamins?
Fruits are relatively rich in vitamin C because they need antioxidants. Except for the seeds, they are relatively poor in B vitamins because they don’t conduct a lot of metabolic activity.
… we don’t really care whether it makes them itself, or steals them from the manufacturer.
Agreed. My question is why the former would be healthier.
Who says that it is healthier? Oh, there are certainly arguments against dining too high on the food chain, but I am very uncomfortable with any blanket claim that vegetarianism is healthier than being omnivorous.
Fruits are relatively rich in vitamin C because they need antioxidants.
You mean the fruits themselves need antioxidants? That’s interesting! And would explain why fruits are high in antioxidants. What do they need them for?
To keep their (concentrated, moist) sugars from oxidizing, and effectively becoming caramel-like or tar-like, and hence less appetizing to the animals that are going to be tricked into distributing the seeds. Or rather, appetizing for too short a time.
Multinationals put anti-oxidants into junk food to promote shelf-life. Nature puts anti-oxidants into fruit to promote branch-life.
Warning! I might just be making this up. Check more authoritative sources if this info matters to you.
Edit: It occurs to me that the essential oils (fragrances) are also subject to being oxidized into something less savory than the original. Maybe more at risk of oxidizing than the sugars.
I would guess this is not true in general since many things do not want to be eaten and so evolve various defense mechanisms. In turn the organisms that eat them may develop counter-measures that enable them to safely digest their meal despite the defense mechanisms but this will depend on the complex evolutionary history of both organisms. Ruminants are adapted to a quite different diet than humans for example.
You’re missing the other side of the story. Humans evolved to obtain their nutritional needs from those foods that were available in the EEA and this effect is probably more significant than the selection pressure in the other direction (on fruits to be nutritionally beneficial to animals that eat them). Humans are adapted to a diet that includes things that were available to them during the long pre-agricultural evolutionary period.
OK. So reading between the lines somewhat and pushing the argument further, would it similarly/analogously/generally be the case that eating nearly any part of an evolutionarily ‘old’, highly evolved autotroph would usually be healthy, because they have learned how to make things that are useful for living things to have? (That is, ignoring the part of the argument possibly implying that we might have evolved a dependency upon apples in particular, because that seemed unlikely to me. Though I could be convinced because know it is the case to some degree for oranges and scurvy, for example.)
I don’t think that is correct. Much autotroph biomass is indigestible (think tree trunks) and some of the rest is deliberately poisonous. A clever plant doesn’t want to be eaten. Furthermore, we ought to eat stuff that has good ingredients—we don’t really care whether it makes them itself, or steals them from the manufacturer. And in any case, different living things are built from slightly different kinds of stuff—a lot of autotrophs don’t even bother with vitamins A, C, D, and E.
And finally, try to avoid using the terms “evolutionarily old” and “highly evolved”. Every living thing you see around you is equally “evolved”, since every living thing has the same “evolutionary age”—roughly 3.5 billion years.
Surely number of generations matters, too?
I’m not sure that this is at all meaningful because things like selection pressure and mutation rate also arguably matter. If one has a species with lots of generations but an incredibly low mutation rate it isn’t going to adapt to an environment as much as another species in the same environment with a higher mutation rate.
Ok, then. Number of generations. Which makes human among the least evolved of all species on the planet. Well, maybe some tortoises are less evolved than us, and maybe elephants and whales and sequoias too, but we certainly have evolved through fewer generations than rats, jellyfish, mosquitoes, sunflowers, earthworms, amoebae, and E. coli.
OK, corrected, thanks. I definitely see the problem with ‘highly evolved’. (For example, a “highly evolved” organism could lose and gain the ability to make a vitamin many times over). I was having trouble separating the ideas of ‘older’ (as in chronologically first) and ‘autotroph’ (as in independent). Animals don’t dependably make the vitamins they need from plants because they can get these vitamins from plants. Plants, though, couldn’t and can’t depend upon something else producing them, so they make them on their own.
Yes, of course. It was sloppy of me not to add the qualifier, ‘if edible’. Instead, what about the validity of this statement: regardless of its edibility, and the amount and type of toxins that might be present, any plant part would be expected to have as many vitamins as a fruit part? The argument being that plants did not have evolutionary pressure to make their fruits particularly full of vitamins?
Agreed. My question is why the former would be healthier. Perhaps because manufacturers sequester more, in greater concentrations?
Animals have abilities to detect whether what they eat is nutritious, plants give the animals what they want. That includes things like Vitamin C—though that isn’t an essential nutrient for most animals.
E.g. see: http://en.wikipedia.org/wiki/Specific_appetite
As mattnewport mentioned above our ancestors evolved to live on fruits. Most animals can synthesis their own vitamin C. We only lost that ability because our ancestors had so much of it in their diet that they didn’t need to synthesize it.
If fruits didn’t contain vitamin C, we wouldn’t have lost the ability to synthesize it, possibly losing the ability to synthesize something else that they did have.
I don’t see any reason for thinking it would be true. Any plant part should be expected to have as many vitamins as it needs to do what that part of a plant does. Different vegetables are rich in different vitamins.
Fruits are relatively rich in vitamin C because they need antioxidants. Except for the seeds, they are relatively poor in B vitamins because they don’t conduct a lot of metabolic activity.
Who says that it is healthier? Oh, there are certainly arguments against dining too high on the food chain, but I am very uncomfortable with any blanket claim that vegetarianism is healthier than being omnivorous.
You mean the fruits themselves need antioxidants? That’s interesting! And would explain why fruits are high in antioxidants. What do they need them for?
To keep their (concentrated, moist) sugars from oxidizing, and effectively becoming caramel-like or tar-like, and hence less appetizing to the animals that are going to be tricked into distributing the seeds. Or rather, appetizing for too short a time.
Multinationals put anti-oxidants into junk food to promote shelf-life. Nature puts anti-oxidants into fruit to promote branch-life.
Warning! I might just be making this up. Check more authoritative sources if this info matters to you.
Edit: It occurs to me that the essential oils (fragrances) are also subject to being oxidized into something less savory than the original. Maybe more at risk of oxidizing than the sugars.
I would guess this is not true in general since many things do not want to be eaten and so evolve various defense mechanisms. In turn the organisms that eat them may develop counter-measures that enable them to safely digest their meal despite the defense mechanisms but this will depend on the complex evolutionary history of both organisms. Ruminants are adapted to a quite different diet than humans for example.