Are humans naturally omnivores?

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In summary, the article discusses the evolution of humans as omnivores, and how this has changed our anatomy and dietary requirements. It also discusses the value systems behind Ecology and Evolution, and how they approach the subject.
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timeuser84
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Hi again, questions in the title, hope you are all doing good and have a nice day
 
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  • #2
How would you define natural as opposed to ... unnatural?
 
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  • #3
Speaking of unnatural, if humans can eat the hot dogs they sell at convenience stores, they can eat anything.
 
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timeuser84 said:
questions in the title
Sorry, only see one question in your title...
 
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  • #5
He meant question's in the title.

He's a man of brevity.
 
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What research have you made in order to answer your question? What are you own thoughts?
 
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timeuser84 said:
Hi again, questions in the title, hope you are all doing good and have a nice day
This is quick to google
 
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DaveC426913 said:
He meant question's in the title.

He's a man of brevity.
Not much in terms of looking of what's posted back though. This and the love post PT 1 and 2.
 
  • #9
The answer is yes, humans evolved to be omnivores, i.e., eat plant matter, and animal matter.

There are multiple choices for "why and how do we know?". One example: humans cannot synthesize vitamin B12 at all.

Humans must rely on the food they eat to supply them with required nutrients like vitamin B12.
Plant matter has no Vitamin B12.

Omnivory solves the problem.
Requirements listed:
https://www.phelpsmemorial.com/six-essential-nutrients-our-bodies-need-and-why

Here is a discussion of the evolution:
Ecol Evol. 2019 Oct; 9(19): 10874–10894.
Published online 2019 Sep 11. doi: 10.1002/ece3.5049
 
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  • #10
yes, Humans are naturally Omnivores and we're anatomically herbivorous.
 
  • #11
Think of cave kid grubbing through the ground cover popping what ever into their mouths. If it didn't kill them they most likely learned what was good and what was not. Animal, vegetable what ever, if it got into its hands, into the mouth it went.
 
  • #12
lata chaudhary said:
yes, Humans are naturally Omnivores and we're anatomically herbivorous.
How do you mean anatomically herbivorous?
 
  • #13
Yes, humans are omnivores. We don't quite match anything in the animal kingdom though, because we have been using fire to cook our food. This has gone on long enough that it has affected our evolution, and changed some carnivore features.

If we define "unnatural" to mean what happens in nature, then a vegetarian diet is unnatural to humans. While a healthy vegetarian diet is possible, it requires nutritional knowledge, and access to resources that were unrealistic until the 20th century.
 
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  • #14
Humans are naturally omnivores. We are capable of choosing a herbivorous diet though and that is what distinguishes us from other omnivorous species.
 
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jim mcnamara said:
The answer is yes, humans evolved to be omnivores, i.e., eat plant matter, and animal matter.

There are multiple choices for "why and how do we know?". One example: humans cannot synthesize vitamin B12 at all.

Humans must rely on the food they eat to supply them with required nutrients like vitamin B12.
Plant matter has no Vitamin B12.

Omnivory solves the problem.
Requirements listed:
https://www.phelpsmemorial.com/six-essential-nutrients-our-bodies-need-and-why

Here is a discussion of the evolution:
Ecol Evol. 2019 Oct; 9(19): 10874–10894.
Published online 2019 Sep 11. doi: 10.1002/ece3.5049
I have to be honest and say that I have real difficulty in linking Ecology with Evolution, I think the two ideas are almost mutually exclusive. I suspect that the extensive discussions that attempt to justify how they approach the subject in the Ecol Evol article is telling.

Ecology sees the natural world in terms of interdependent stable networks and addresses changes as threats. The discussions really reflect a value system that reflects a desire for an unchanging natural environment and see's human agency as destructive. So there is considerable emphasis on extinctions, environmental damage, restoration of ecosystems and the reintroduction of species, which are discussed as having a functional role in the ecology.

Evolution on the other hand is essentially about how species adapt to an ever changing environment, extinctions are seen as an essential in the evolution of new species and inevitable. There are currently more species on earth than there has ever been this largely being a function of time and whatever the functional role of a species might be this isnt a driver of evolutionary change.

Like most species, we have over time developed the tools and strategies needed to survive and reproduce, the problem in this case is in gaining the nutrients needed. The fact that the same sort of nutrients are often required by all species means there will be competition for their sources and attempts to protect the nutrients we have. Ultimately, there are a wide range of strategies that can be involved in this, with each having its own advantages and costs and all to some extent limiting the choices available.

In the evolution of life we see increasingly complex strategies used to gain and compete for nutrients. In evolutionary theory, the environmental drivers are not the functional role of a species in an ecological niche, it is what is available to exploit and how best to exploit it. The natural world is not a world in balance, its a world of boom and bust. We can't really trace the evolution of feeding strategies past the days the early origins of life because its a history of natural selection not development. Dietary choice is perhaps best understood using cost benefit analysis.
 
  • #16
There are situations where the presence of various species in a species' environment are important to its evolution (either living or going extinct or in what way a species might be elaborated in evolution).
Examples: A parasite needs its host or it will go extinct. The availability of new species in a parasite's environment could provide a new evolutionary path that the parasite might take, to find and become specialized to a new host.
There could be lots of other examples involving new relationships of various kinds among species that might get introduced into a species environment (which includes other species in its environment).

There other things than just nutrients that get competed for, like space in the environment.

Laroxe said:
We can't really trace the evolution of feeding strategies past the days the early origins of life because its a history of natural selection not development.
Perhaps I misunderstand what you are saying but, various aspects of how feeding strategies have evolved have been studied.
The history of changes in the electron transfer chain have been studied and how it enabled living things to extract a chemical living from different redox pairs of chemicals. Indications of this can be found in genomes.

Here are some examples of redox pairs from: https://www.sciencedirect.com/science/article/pii/S2468867319300574
Screenshot 2023-04-17 at 1.14.18 PM.png

Olivia Judson also wrote a more general paper about the different ways biology makes use of energy through evolution: The energy expansions of evolution.
Nature Ecology & Evolution 1, 0138 (2017) | DOI: 10.1038/s41559-017-0138 | www.nature.com/natecolevol
 
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  • #17
Humans can thrive without any plant material in their diet, just have to eat raw meat to get vitamin C and other nutrients that get destroyed by cooking - its how the Inuit and other arctic people survived

And our closest primate relatives - chimps and bonobos - eat meat
 
  • #18
Laroxe said:
I have to be honest and say that I have real difficulty in linking Ecology with Evolution, I think the two ideas are almost mutually exclusive. ...

Ecology sees the natural world in terms of interdependent stable networks and addresses changes as threats. The discussions really reflect a value system that reflects a desire for an unchanging natural environment and see's human agency as destructive. So there is considerable emphasis on extinctions, environmental damage, restoration of ecosystems and the reintroduction of species, which are discussed as having a functional role in the ecology.

Evolution on the other hand is essentially about how species adapt to an ever changing environment, extinctions are seen as an essential in the evolution of new species and inevitable.

Well I don't want to go extinct, do you? Ecology is the human science of guiding evolution to keep the world in a state we humans like. When we say we need to "Save the Earth" or "Save the environment", this is shorthand for "Save the Earth's ability to support lots of humans in comfort." Extinction is natural. That doesn't mean it is good for us.

When Earth's environment undergoes sudden changes, it is usually the big complex species like us that die off. We are the ones that need interdependent stable networks. Simple, rapidly reproducing organisms then dominate for a while, until new and different interdependent networks evolve.

Ecology tends to focus on resisting and undoing change. This is because the living environment is a chaotic system. It is impossible to predict what the long term consequences of large changes are. Most of the Earth's history is filled with life, yet an atmosphere unbreathable to humans! We have no idea how much change we can get away with before that happens again. Far smaller changes could radically reduce human's ability to grow food, and thus wipe out human civilization before we have time to react.

So there is no conflict between ecology and evolution. With billions of humans on the planet, we will need to understand both, and act wisely, to survive.
 
  • #19
timeuser84 said:
Hi again, questions in the title, hope you are all doing good and have a nice day
Lots of input. What do you think?
 
  • #20
BillTre said:
There are situations where the presence of various species in a species' environment are important to its evolution (either living or going extinct or in what way a species might be elaborated in evolution).
Examples: A parasite needs its host or it will go extinct. The availability of new species in a parasite's environment could provide a new evolutionary path that the parasite might take, to find and become specialized to a new host.
There could be lots of other examples involving new relationships of various kinds among species that might get introduced into a species environment (which includes other species in its environment).

There other things than just nutrients that get competed for, like space in the environment.Perhaps I misunderstand what you are saying but, various aspects of how feeding strategies have evolved have been studied.
The history of changes in the electron transfer chain have been studied and how it enabled living things to extract a chemical living from different redox pairs of chemicals. Indications of this can be found in genomes.

Here are some examples of redox pairs from: https://www.sciencedirect.com/science/article/pii/S2468867319300574
View attachment 325030
Olivia Judson also wrote a more general paper about the different ways biology makes use of energy through evolution: The energy expansions of evolution.
Nature Ecology & Evolution 1, 0138 (2017) | DOI: 10.1038/s41559-017-0138 | www.nature.com/natecolevol
Sorry Billtre, I expressed what I was thinking very badly, I was trying to get away from the idea of evolution reflecting development within a species, and failed miserably. Organisms develop the ability to use what is available but of course the sources available totally depend on the environment.

I think that part of my problem was in the links between ecology, which reflects human value systems and evolution, its an issue reflected in Algr's comments when he describes ecology as the science of guiding evolution and he asks if I want to go extinct. While the answer to that is no, the chances are that we will, 99% of species that ever evolved are now extinct, evolution favours change and the idea that we can effectively guide it borders on delusional.

We really need to consider how conservation efforts reflect our values and have nothing to do with any direction from nature, its true that specific environmental changes may not be good for us as individuals but if the Cretaceous–Tertiary extinction even hadn't occurred there wouldn't be any humans.

I do value the environment but am acutely aware of the fact that what we value can be the basis for a science, it distorts our understanding of nature. I would suggest that current human value systems, based on a lack of understanding represents the greatest threat to our existence. Then believe it or not these value systems distort the way in which we consider our dietary requirements with the food that we eat becoming a battle ground between facts and values.
 
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Related to Are humans naturally omnivores?

Are humans naturally omnivores?

Yes, humans are naturally omnivores. This means that our physiology and digestive systems are adapted to consume both plant and animal-based foods.

What evidence supports that humans are omnivores?

There is a range of evidence supporting that humans are omnivores, including our dental structure, digestive enzymes, and the ability to derive nutrients from both plant and animal sources. Our teeth include incisors and canines for tearing meat, as well as molars for grinding plant material. Additionally, our digestive system produces enzymes like amylase for breaking down carbohydrates and pepsin for proteins.

How do human teeth indicate an omnivorous diet?

Human teeth are indicative of an omnivorous diet because they include a variety of types suited for different kinds of food. Incisors and canines are sharp and pointed, ideal for cutting and tearing meat, while molars and premolars have flat surfaces for grinding and chewing plant material.

Do humans need to eat meat to be healthy?

While humans are naturally omnivores, it is possible to maintain a healthy diet without consuming meat. A well-planned vegetarian or vegan diet can provide all the necessary nutrients, although it may require more attention to ensure adequate intake of certain nutrients like vitamin B12, iron, and omega-3 fatty acids.

How does human evolution support the idea that we are omnivores?

Human evolution supports the idea that we are omnivores through the analysis of fossil records and the study of early human diets. Early humans and their ancestors consumed a varied diet that included both plant and animal sources. This dietary flexibility likely contributed to our survival and adaptation in diverse environments.

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