There's a reason grass is so common - it's because it's a wildly effective life strategy. Grass is actually quite hard to eat - there's basically no nutrition in the leaves themselves, and grass evolved to incorporate silica "needles" in its leaves, so that it wears down your teeth when you try to eat it anyways.
Not to say that it's impossible to eat grass, but you need to undergo a ton of highly specialized adaptations to make it possible. For most animals (including humans), it's just not worth the effort
Ruminants that eat it have like several stomachs, they regurgitate the food they eat to re-eat it, and they require specialized gut bacteria to digest it. They have to spend like all of their time eating.
Plants are selected to not be great to eat, basically. Cellulose in particular is almost impossible to biochemically break back down (but not completely), and is a pretty good structural material, too.
Seeds are often still palatable once you get through the shell, basically because turning into a baby plant is an already tough design constraint. Some plants still have tricks - notice that it's the spiciest part of a hot pepper.
Grass is mostly cellulose and lignin. Those molecules are difficult to break down.
Animals that can digest the cellulose either need a really long digestive track or to do something really gross to keep the stuff in their digestive track longer.
Folks have looked at it with acid or enzymes to try and produce fuel ethanol from the sugar forming the cellulose. Humans use the chemistry of grazing animals.
Rye used to be a weed that evolved to resemble wheat so early farmers wouldn't uproot it. But it evolved to resemble wheat so much that it became an edible crop in its own right.
The thing is that cows can't digest grass either. They have an extra stomach along their oesophagus which is basically just a pouch where the grass goes in first. There are a lot of bacteria and they can digest grass. Then these bacteria grow because they eat the grass.
Then the cow swallows these bacteria and digests those. That's where a cow gets their calories from.
when you eat fruit, the sugar can enter your bloodstream directly through the mucosa in your mouth, you don't even need to swallow it. although the main part of the absorption happens in the colon still.
It's all down to the way the brain works. Our brains use up something like 20% of our calories when standing still doing nothing.
Grass does not supply the amount of calories and micronutrients needed to keep the human brain running, simply because it is low on both of those things.
Grass eaters have multiple stomachs, slow digestion and graze pretty much the whole time they're awake, and because their brains use a lot less energy than human brains, the balance works out.
Vegetables have pretty limited availability for protein, as an animal you have sit there eating grass all day. Our ways allow us plenty of time to be smart & stuff
Because it requires a lot of biological investment to eat it. It's rough on teeth and requires rumination or similar calorically expensive techniques to extract much nutrition. We evolved in the opposite path and optimized heavily for easily digested foods. We then take it a step further and cook them breaking the difficult to digest parts into an easer to digest form.
Also we do eat grasses, but only their seeds and fruits. Wheat, maize, rice, and bananas are all grasses
Essentially as others said, because you need to invest heavily in your gut and metabolism to get enough energy out of grass alone. You don't evolve into what you want, you evolve into what you can while you are pressured to do so. There is currently no pressure to rely solely on grass, that pressure hasn't been on us for millions of years. Our foods may be trickier to find but on average they yield more energy compared to grass.
But don't get me wrong. It's a valid strategy. Our ancestors did have the window of opportunity at some point, and they took it... We were something more like rats back then, the grass eaters niche had room. Grass was everywhere. And our cousins back then adapted and spent practically the whole day foraging for grass in order to get by. But you know what also was everywhere? Trees. And our ratlike ancestors that were more inclined to climb, jump, and spot predators from above found it easier to stick to the omnivore diet.
Adapting to trees lets you move into places with less grass... Like jungles and swamps. And while you are there for a couple million years you will have other problems to solve, problems that require wits, sharp vision, and social skills. You don't have time to forage 18hrs every day and grass isn't as abundant here anyway.
If you don't rely solely on grass you will probably fare better during winter. Especially during those ice ages. By the time you have grass as an option again you are pretty much an ape and pivoting back to it makes no sense.
Grass is nutritionally poor. The reason we are smart in many ways is due to our varied diet. Even if we had evolutionary gone in that direction we would be dumber. Eating grass is a specialisation.
Also, we would not look like we do. If you look at the digestive track of a horse or a cow, you will see that they are longer. Carnivores have the shortest and we as omnivores are in between. Being an omnivote is a good thing and in the end, we can get more nutrition by hunting and gathering than by grassing.
Worth noting, while individual cows' behaviour and preferences vary greatly, the time spent feeding and ruminating usually adds up to 4-7 hours a day. Our society would be were we are today if we spent 7 hours as a species eating grass in order to make ir worthwhile.
Evolution can only evolve so much within an existing animal especies in order to specialise or fit in a survival niche. Hence you do not see sea crabs that can fly or flies that live in the bottom of the sea.
If you look at all the other animals in the world that do eat grass, we did. But the "we" that eat grass, look like those animals, with those traits.
The "we" that became smart became so due to what we evolved to eat and do.
Sentience is the ability to perceive your surroundings using your senses. What cows (probably) haven't achieved is sapience, roughly the ability to think about more than your immediate sensual impressions, in the abstract. Modern humans have decided they are extra sapient, hence "homo sapiens sapiens" whereas Neanderthals are "homo sapiens neanderthalensis".
Yeah, that was the lazy answer. The more correct is, because grass contains stuff (mainly lignin, reminds me of this i found this morning) that's hard to digest with a normal stomach. So cows & co. have multiple gastric ... sections(? Mägen), the first of which contains microrganisms specialized in breaking down lignin. The following gastrics are more the usual bio-chemical kind, to digest the microorganisms.
In short, eating grass needs a specialized process and you can't eat anything else as main food source, (they do occasionally eat a chicken or critter).
Evolution is a purely subtractive process. It doesn't design things in, it just removes poorly-designed creatures (and all hypothetical offspring) until only things equipped to survive are left. And obviously, there are things to eat that aren't grass.
Edit: Herbivores can be smart, even the grazers. Look at elephants.
I can't believe how many other replies heap that fallacy on top of teleological evolution. Apes are mostly herbivorous anyway, WTF.
In the sense humans are "better" or "greater" or something? Well, consider the global biomass of bacteria compared to humans - they seem to be doing okay. Or that there's more bacterial cells in you than human cells. Single-celled yeast evolved from mushrooms, barnacles evolved from something like shrimp or crabs, and there are eukaryotes that lost eukaryotic features like mitochondria because they didn't need them to survive.
Buuut that's besides the point. I'm not sure how to make it more clear, but I meant subtractive as in selection is just about who dies. Random mutation is what adds features and new species.
59 Comments
Contramuffin@lemmy.world · 61 pts · 147d
There's a reason grass is so common - it's because it's a wildly effective life strategy. Grass is actually quite hard to eat - there's basically no nutrition in the leaves themselves, and grass evolved to incorporate silica "needles" in its leaves, so that it wears down your teeth when you try to eat it anyways.
Not to say that it's impossible to eat grass, but you need to undergo a ton of highly specialized adaptations to make it possible. For most animals (including humans), it's just not worth the effort
teyrnon@sh.itjust.works · 26 pts · 146d
Ruminants that eat it have like several stomachs, they regurgitate the food they eat to re-eat it, and they require specialized gut bacteria to digest it. They have to spend like all of their time eating.
doomsdayrs@lemmy.ml · 2 pts · 146d
I'd like a source on the silica needles?
Cyteseer@lemmy.world · 11 pts · 146d
Basically all grasses contain silica phytoliths but they likely don't significantly contribute to teeth wear. https://www.sciencedirect.com/science/article/abs/pii/S0305440306001245
Contramuffin@lemmy.world · 3 pts · 146d
Interesting, thanks for sharing that. I wasn't aware that there has been newer research countering the tooth wear model
doomsdayrs@lemmy.ml · 2 pts · 146d
Thank you very much Sis! ✨
pelespirit@sh.itjust.works · 39 pts · 147d
All forms of grass:
Mothra@mander.xyz · 22 pts · 147d
We eat the seeds, I presume OP refers to the leaves/blades of grass which are also present in species that aren't cereals
pelespirit@sh.itjust.works · 10 pts · 147d
Good point. This made me look further, but some of these also are just the seeds:
https://smartgardenhome.com/edible-plants/grasses/
fizzle@quokk.au · 6 pts · 147d
Bamboo shoots are a common ingredient.
CanadaPlus@futurology.today · 5 pts · 147d
Plants are selected to not be great to eat, basically. Cellulose in particular is almost impossible to biochemically break back down (but not completely), and is a pretty good structural material, too.
Seeds are often still palatable once you get through the shell, basically because turning into a baby plant is an already tough design constraint. Some plants still have tricks - notice that it's the spiciest part of a hot pepper.
Eh_I@lemmy.world · 1 pts · 146d
Every species of grain:
Wheat
etc
etchinghillside@reddthat.com · 37 pts · 147d
Smarts required more calories.
Alcoholicorn@mander.xyz · 23 pts · 147d
Grass is mostly cellulose and lignin. Those molecules are difficult to break down.
Animals that can digest the cellulose either need a really long digestive track or to do something really gross to keep the stuff in their digestive track longer.
Peppycito@sh.itjust.works · 7 pts · 147d
Looking at you, rabbits.
Alcoholicorn@mander.xyz · 3 pts · 147d
Deer too, but slightly less gross, and some others.
NKBTN@feddit.uk · 2 pts · 146d
Any chemistry we could perform to make it more viable? E.g. cook it with alcohol?
INeedANewUserName@piefed.social · 2 pts · 146d
Folks have looked at it with acid or enzymes to try and produce fuel ethanol from the sugar forming the cellulose. Humans use the chemistry of grazing animals.
NKBTN@feddit.uk · 2 pts · 146d
Yeah the grass to milk, meat and hide pipeline is a great one
daannii@lemmy.world · 22 pts · 147d
A lot of grass. Like lawn grass. Is wheat.
If you let it grow more.
So actually we did evolve to eat grass.
Cat grass is wheat grass.
Infrapink@thebrainbin.org · 24 pts · 147d
Rye, barley, oats, and rice are also grasses.
Rye used to be a weed that evolved to resemble wheat so early farmers wouldn't uproot it. But it evolved to resemble wheat so much that it became an edible crop in its own right.
pastermil@sh.itjust.works · 14 pts · 146d
they faked it until they made it!
100_kg_90_de_belin@feddit.it · 8 pts · 147d
Vavilovian mimicry goes brrr
electric_nan@lemmy.ml · 2 pts · 146d
Don't forget corn!
ICastFist@programming.dev · 3 pts · 146d
Bamboo is also grass, we can eat the shoots/sprouts
gandalf_der_12te@discuss.tchncs.de · 18 pts · 146d
The thing is that cows can't digest grass either. They have an extra stomach along their oesophagus which is basically just a pouch where the grass goes in first. There are a lot of bacteria and they can digest grass. Then these bacteria grow because they eat the grass.
Then the cow swallows these bacteria and digests those. That's where a cow gets their calories from.
SaveTheTuaHawk@lemmy.ca · 2 pts · 146d
Humans can't digest anything without bacteria either.
gandalf_der_12te@discuss.tchncs.de · 7 pts · 146d
they can
when you eat fruit, the sugar can enter your bloodstream directly through the mucosa in your mouth, you don't even need to swallow it. although the main part of the absorption happens in the colon still.
FriendBesto@lemmy.ml · 1 pts · 145d
Albeit true, not to the extent of cows.
FriendBesto@lemmy.ml · 1 pts · 145d
Cows only have 1 stomach. That is devided in 4 compartments.
ada@piefed.blahaj.zone · 16 pts · 147d
It's all down to the way the brain works. Our brains use up something like 20% of our calories when standing still doing nothing.
Grass does not supply the amount of calories and micronutrients needed to keep the human brain running, simply because it is low on both of those things.
Grass eaters have multiple stomachs, slow digestion and graze pretty much the whole time they're awake, and because their brains use a lot less energy than human brains, the balance works out.
pineapple@lemmy.ml · 15 pts · 146d
Take the tier zoo aproach. Would you rather use evelution points on grass or evolution points on being big brain.
Karl@literature.cafe · 8 pts · 146d
Grass.
webp@mander.xyz · 18 pts · 146d
Some of us did that and they are horses now.
Karl@literature.cafe · 3 pts · 146d
racoon@lemmy.ml · 4 pts · 146d
thatsnomayo@lemmy.ml · 13 pts · 147d
Vegetables have pretty limited availability for protein, as an animal you have sit there eating grass all day. Our ways allow us plenty of time to be smart & stuff
scutiger@lemmy.world · 6 pts · 147d
I mean we've got the time, but we still don't do it.
thatsnomayo@lemmy.ml · 4 pts · 147d
I mean pandaz tried going back 2 the bark and kt takes their whole ass day. No phone time. Imagine?
FriendBesto@lemmy.ml · 1 pts · 145d
But at least we have the choice. Cows don't.
basket@pie.gravitywell.xyz · 13 pts · 147d
Return to cow
Quilotoa@lemmy.ca · 10 pts · 146d
I'd rather evolve the ability to photosynthesize, now that we have indoor lighting. It'd save a whole bunch of time and grocery bills.
captainlezbian@lemmy.world · 10 pts · 145d
Because it requires a lot of biological investment to eat it. It's rough on teeth and requires rumination or similar calorically expensive techniques to extract much nutrition. We evolved in the opposite path and optimized heavily for easily digested foods. We then take it a step further and cook them breaking the difficult to digest parts into an easer to digest form.
Also we do eat grasses, but only their seeds and fruits. Wheat, maize, rice, and bananas are all grasses
Mothra@mander.xyz · 8 pts · 147d
Essentially as others said, because you need to invest heavily in your gut and metabolism to get enough energy out of grass alone. You don't evolve into what you want, you evolve into what you can while you are pressured to do so. There is currently no pressure to rely solely on grass, that pressure hasn't been on us for millions of years. Our foods may be trickier to find but on average they yield more energy compared to grass.
But don't get me wrong. It's a valid strategy. Our ancestors did have the window of opportunity at some point, and they took it... We were something more like rats back then, the grass eaters niche had room. Grass was everywhere. And our cousins back then adapted and spent practically the whole day foraging for grass in order to get by. But you know what also was everywhere? Trees. And our ratlike ancestors that were more inclined to climb, jump, and spot predators from above found it easier to stick to the omnivore diet.
Adapting to trees lets you move into places with less grass... Like jungles and swamps. And while you are there for a couple million years you will have other problems to solve, problems that require wits, sharp vision, and social skills. You don't have time to forage 18hrs every day and grass isn't as abundant here anyway.
If you don't rely solely on grass you will probably fare better during winter. Especially during those ice ages. By the time you have grass as an option again you are pretty much an ape and pivoting back to it makes no sense.
FriendBesto@lemmy.ml · 7 pts · 145d
Grass is nutritionally poor. The reason we are smart in many ways is due to our varied diet. Even if we had evolutionary gone in that direction we would be dumber. Eating grass is a specialisation.
Also, we would not look like we do. If you look at the digestive track of a horse or a cow, you will see that they are longer. Carnivores have the shortest and we as omnivores are in between. Being an omnivote is a good thing and in the end, we can get more nutrition by hunting and gathering than by grassing.
Worth noting, while individual cows' behaviour and preferences vary greatly, the time spent feeding and ruminating usually adds up to 4-7 hours a day. Our society would be were we are today if we spent 7 hours as a species eating grass in order to make ir worthwhile.
Evolution can only evolve so much within an existing animal especies in order to specialise or fit in a survival niche. Hence you do not see sea crabs that can fly or flies that live in the bottom of the sea.
TribblesBestFriend@startrek.website · 5 pts · 147d
I think that grass don’t have enough energy to sustain our brain and its development.
TachyonTele@piefed.social · 5 pts · 147d
Because yo mama so fat she'd eat it all
rants_unnecessarily@piefed.social · 5 pts · 147d
If you look at all the other animals in the world that do eat grass, we did. But the "we" that eat grass, look like those animals, with those traits.
The "we" that became smart became so due to what we evolved to eat and do.
deegeese@sopuli.xyz · 4 pts · 147d
Why haven’t cows evolved sentience?
Grazing lifestyle doesn’t favor big expensive brains.
Lumidaub@feddit.org · 5 pts · 147d
Sentience is the ability to perceive your surroundings using your senses. What cows (probably) haven't achieved is sapience, roughly the ability to think about more than your immediate sensual impressions, in the abstract. Modern humans have decided they are extra sapient, hence "homo sapiens sapiens" whereas Neanderthals are "homo sapiens neanderthalensis".
MonkderVierte@lemmy.zip · 4 pts · 145d
Grass came later.
Karl@literature.cafe · 1 pts · 145d
Not after chicken nuggies tho?
MonkderVierte@lemmy.zip · 2 pts · 145d
Yeah, that was the lazy answer. The more correct is, because grass contains stuff (mainly lignin, reminds me of this i found this morning) that's hard to digest with a normal stomach. So cows & co. have multiple gastric ... sections(? Mägen), the first of which contains microrganisms specialized in breaking down lignin. The following gastrics are more the usual bio-chemical kind, to digest the microorganisms.
In short, eating grass needs a specialized process and you can't eat anything else as main food source, (they do occasionally eat a chicken or critter).
lemmylump@lemmy.world · 4 pts · 147d
We evoled away from eating grass and other such things, it's why our appendix are now almost useless.
CanadaPlus@futurology.today · 3 pts · 147d
That random mutation didn't happen, basically.
Evolution is a purely subtractive process. It doesn't design things in, it just removes poorly-designed creatures (and all hypothetical offspring) until only things equipped to survive are left. And obviously, there are things to eat that aren't grass.
Edit: Herbivores can be smart, even the grazers. Look at elephants.
I can't believe how many other replies heap that fallacy on top of teleological evolution. Apes are mostly herbivorous anyway, WTF.
kunaltyagi@programming.dev · 2 pts · 147d
Evolution is not subtractive. Bacteria didn't evolve from humans
CanadaPlus@futurology.today · 1 pts · 146d
In the sense humans are "better" or "greater" or something? Well, consider the global biomass of bacteria compared to humans - they seem to be doing okay. Or that there's more bacterial cells in you than human cells. Single-celled yeast evolved from mushrooms, barnacles evolved from something like shrimp or crabs, and there are eukaryotes that lost eukaryotic features like mitochondria because they didn't need them to survive.
Buuut that's besides the point. I'm not sure how to make it more clear, but I meant subtractive as in selection is just about who dies. Random mutation is what adds features and new species.
tlekiteki@lemmy.dbzer0.com · 3 pts · 147d
MOOOOOO MOooO MU
BagOfHeavyStones@piefed.social · 2 pts · 147d
Justified and Ancient?
Alsjemenou@lemy.nl · 2 pts · 146d
Why? Because otherwise we wouldn't exist and that wouldn't be in line with the future.