It’s everywhere. Why not just eat it instead of searching for veggies and meat which are more difficult to have?
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
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.
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.
I’d like a source on the silica needles?
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
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.
Humans can’t digest anything without bacteria either.
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.
Grass came later.
Not after chicken nuggies tho?
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).
All forms of grass:
- Corn
- Wheat
- Barley
- Rice
- etc
We eat the seeds, I presume OP refers to the leaves/blades of grass which are also present in species that aren’t cereals
Good point. This made me look further, but some of these also are just the seeds:
- Bamboo
- Bluegrass
- Crabgrass
- Foxtail Grass
- Goosegrass
- Lemongrass
- Wood Millet
- Orchardgrass
Bamboo shoots are a common ingredient.
Smarts required more calories.
Take the tier zoo aproach. Would you rather use evelution points on grass or evolution points on being big brain.
Grass.
Some of us did that and they are horses now.
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.
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.
they faked it until they made it!
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.
Any chemistry we could perform to make it more viable? E.g. cook it with alcohol?
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.
Yeah the grass to milk, meat and hide pipeline is a great one
