What are the disadvantages of being an omnivore?

[♔Goodguy1066♔]

Are there any disadvantages of being an omnivore? If so, what are they? If not, why didn't all animals evoloutionise into being omnivores instead of carnivores/herbivores? Also, does the word "omnivoressness" exist? If not, what is the equivilant of the word?

Sorry about my ignorance, just curious...

[Tia]

One disadvantage is the lack of specialized teeth. Omnivores usually generally have a larger appetite and eat more.
As for the word issue, i'm not entirely sure.

[Portuguese Rebel]

Very little disadvantage. Many of the most successful animal groups are opportunistic omnivores. Rodents, several insects, Humans... All highly successful. It is not that you have a disadvantage per se as in much you lack the advantages other more specialized beings have. When morphology adapts to be an herbivore or carnivore you can become more successful until conditions get really hard. If somehow your food supply goes away (glaciations anyone...) then you would be better off being less specialized.

[Sphere]

Digesting cellulose (the tough, woody part of plants) its actual rather difficult, and takes special adaptations, often using multiple stomachs. Most herbivores specialize in digesting plants with high cellulose (grasses, shrubs, bamboo, leaves etc) as they are inedible to other creatures. Most omnivores digestive systems are limited to much simpler sugars which are less abundant.

[Elfdude]

Originally I'd bet most animals were omnivores. Overtime some animals gained the ability to metabolize common but hard to digest plant matter opening themselves up to a whole host of plants. Their omnivore teeth became flatter as they evolved to metabolize more and more plant matter. Because of the abundance of plant matter herbivores grow big and fast and get larger and larger to compensate. Carnivores appear and act like a balancing mechanism because as more animals take advantage of converting plant material into animal material more meat food becomes available. The upper limit for the number of these animals depends on the amount and complexity of the resources they have to take advantage of.

Omnivores for the most part are a third middle line. Throughout evolution omnivores get pushed out by both carnivores and herbivores who are both more effective at taking advantage of their food resources. Carnivores need muscle mass and teeth and power and focus. Herbivores need areas to breed probiotic organisms in their guts, frames to carry their mass, flat teeth and broad awareness of their surroundings. The only reason monkeys were able to keep their omnivorous habits is because of the wide abundance of both resources in their original habitats and the ability to hide from larger faster predators and escape tree to tree from any other.

Case in point in a pine forest most humans wouldn't be able to survive without a wide variety of knowledge about their environment or tools to hunt. Herbivores would be able to live off of the nutrient bare plant material. Carnivores would be able to hunt. Omnivores have no real advantage over the other two. Intelligence allows omnivores however to learn about extremely dense food that few other non specialized animals can capitalize on. Give that a couple million years and spice it up with a few more pressures to become intelligent and you get us.

Also, I don't know of any real carnivore that eats meat exclusively. They and us as well are just bad at getting nutrients from plant matter.

[cpdwane]

Originally I'd bet most animals were omnivores. Overtime some animals gained the ability to metabolize common but hard to digest plant matter opening themselves up to a whole host of plants. Their omnivore teeth became flatter as they evolved to metabolize more and more plant matter. Because of the abundance of plant matter herbivores grow big and fast and get larger and larger to compensate. Carnivores appear and act like a balancing mechanism because as more animals take advantage of converting plant material into animal material more meat food becomes available. The upper limit for the number of these animals depends on the amount and complexity of the resources they have to take advantage of.

What sort of time period are you talking about? To the best of my knowledge, there is no time recorded in the fossil record when there wasn't a distinction between carnivore and herbivore.

[Elfdude]

What sort of time period are you talking about? To the best of my knowledge, there is no time recorded in the fossil record when there wasn't a distinction between carnivore and herbivore.

Billions of years time period. When you get down to it the requirements for both animals isn't different but the way they go about obtaining it is which to me speaks of a link at some point.

[Phier]

In a nutshell being specialized is advantageous in 'good times', when they can maximize their diets and by default reproduction.

Being an omnivore gives you more options but at the cost of efficiency.

[chamaeleo]

Elfdude and Phier hit it on the head: flexibility vs efficiency, the classic conflict.

Technically, it's the endosymbiont community in the herbivores' digestive tract which digests cellulose. Maintaining a consistent diet keeps your gut fauna relatively happy...a simple task for specialist critters (carnis and herbis), whereas omni gut communities must adapt to daily fluctuations in food types and quantities. Case in point: I nuked my community yesterday w a particularly spicy red chile-smothered enchilada. Last night was downright painful, and today has been unpleasant...tomorrow I should be OK. Meanwhile, "I'm" not digesting my food at 100% efficiency as my lil buddies scramble to reestablish a healthy population in my gut. I'll likely kill em off again Sat night w copious amounts of wasabi...that's just the fate of omnivorous endosymbionts...

[Elfdude]

I'm not sure that spicy food should do that. Nor should your body be reacting to it in a negative way. Spice improves the digestive system's functions and helps repress bacteria in the upper digestive system. More likely the food you're eating doesn't have enough fiber/binders/accessible moisture. Also your anus doesn't burn because of spice you've eaten but because of digestive fluids left in the stool. Your description speaks of a bacteria infection or a mild food allergy or perhaps IBS.

Case in point I eat habaneros like candy and digestive system runs perfectly.

[Nik]

Billions of years time period

I though multi-cellular, eukaryotic lifeforms existed less than one billion years, and the distinction between plant and animal is on the scale of several hundred million years. Is it even possible to define clear temporal moments were herbivores and omnivores developped in relation to the development of "Plants" and "animals"?

[Elfdude]

I though multi-cellular, eukaryotic lifeforms existed less than one billion years, and the distinction between plant and animal is on the scale of several hundred million years. Is it even possible to define clear temporal moments were herbivores and omnivores developped in relation to the development of "Plants" and "animals"?

No we can't calculate it exactly. I don't think that's the point however. Logically the origin of animal digestion would have been omnivorous with consideration given to the nutrients not the way they were obtained.

[chamaeleo]

No we can't calculate it exactly. I don't think that's the point however. Logically the origin of animal digestion would have been omnivorous with consideration given to the nutrients not the way they were obtained.

What are we to consider the "first" animal? Sponges...being the first multicellular critter w decent fossil representation? If so, does indiscriminant filter-feeder = (perhaps, the "ultimate") omnivore?

To me, the most glaring absence in evolutionary history is that of most major lineages of microbes. Despite having observed the dramatic effects of disease in modern history, it scarcely receives mention in Big picture discussions. After all, it's the little guys who keep this world running: 90% of the cells in your body are not even yours. Nevermind, the symbiont origin of mitochondria, without which eukaryotes would never have evolved!

[Portuguese Rebel]

To me, the most glaring absence in evolutionary history is that of most major lineages of microbes. Despite having observed the dramatic effects of disease in modern history, it scarcely receives mention in Big picture discussions.

You bet, poor anonymous micro-heroes!