Plants: Manufacture fructose
Animals: Do not manufacture fructose
Humans: Manufacture fructose
Plants: Are able to gather energy from the sun
Animals: Cannot gather energy from the sun
Humans: Are able to gather energy from the sun
There are two fallacies being used in this logic. The first fallacy is that of cherry picking. I have chosen only the data which confirms my conclusion that humans are plants. I have also cherry picked my definition of animals to include only the animals fitting the stereotypes I have defined. The second fallacy is guilt by association (which is itself an example of the fallacy of the undistributed middle). We have argued that all plants have some characteristic and all humans have the same characteristic and then tried to conclude from that fact that all humans are plants (although if we had a true dichotomy between being either animal or plant then actually showing that humans were not animals would be sufficient evidence to show that we were plants).
We can do better than simply pointing out that the logic behind this argument is flawed however, we can in most cases even explain why humans as traditional omnivores do not possess all these characteristics often possessed by other meat-eating species.
I have taken this post as a good example of the argument we are discussing.
Facial MusclesCARNIVORE: Reduced to allow wide mouth gape
Why are reduced facial muscles necessary for most meat eaters? The post even explains in the case of carnivores that it is in order to allow for a wide mouth gape. Some carnivores and omnivores hunt using their mouths as an important instrument in the kill. Humans do not use this method. We have historically used our hands in combination with tools in order to hunt and thus have never needed a wide mouth gape in order to hunt. This same explanation applies to why we have a seemingly herbivorous jaw type, jaw joint location, jaw motion, major jaw muscles, mouth opening versus head size, teeth of all types. There are still carnivorous and omnivorous species which do not hunt large prey with their mouths. Pigs are omnivores, eating leaves, grasses, roots, flowers, as well as insects and dead carcasses in the wild. Since their hunting style doesn't require them to kill large animals with their mouths they have facial structures very similar to our own in all of these areas.
Stomach CapacityCARNIVORE: 60% to 70% of total volume of digestive tract
HERBIVORE: Less than 30% of total volume of digestive tract
OMNIVORE: 60% to 70% of total volume of digestive tract
HUMAN: 21% to 27% of total volume of digestive tract
Once again this applies to carnivorous and omnivorous species that hunt large prey. These animals often go for long periods between meals and then will consume a single large meal to survive on for long periods at a time. Most herbivores tend to graze throughout the day, not needing to hold a single large meal in their stomachs at once. Humans as animals that have evolved in small tribal settings have been able to share the meat of large kills with members of their community and have otherwise continued to typically eat several small meals throughout the day.
ColonCARNIVORE: Simple, short and smooth
HERBIVORE: Long, complex; may be sacculated
OMNIVORE: Simple, short and smooth
HUMAN: Long, sacculated
Humans are along with all other primates in having sacculated colons. Ruminants are another group that tends to have sacculated colons. Sacculation of the colon in simple terms simply refers to the structure of tucks and pouches we find in our colon. In humans and primates this is thought to be a special adaptation to fermentation, allowing us to extract more energy from fiber.Source This adaptation would not be useful for carnivores who don't consume any significant amount of fiber. For other omnivores and many other herbivores they have likely all struck upon different solutions for improving digestion of fiber which doesn't require sacculation of the colon, much as many animals have evolved unique solutions to solving the problem of seeing.
KidneyCARNIVORE: Extremely concentrated urine
HERBIVORE: Moderately concentrated urine
OMNIVORE: Extremely concentrated urine
HUMAN: Moderately concentrated urine
Animals with unconcentrated urine risk wasting too much water in order to excrete wastes through their urine. Animals with concentrated urine put themselves at higher risk of developing kidney stones and other kidney issues. Being a carnivore or herbivore has very little to do with striking this balance, while the prevalence of water plays a much larger role.
NailsCARNIVORE: Sharp claws
HERBIVORE: Flattened nails or blunt hooves
OMNIVORE: Sharp claws
HUMAN: Flattened nails
Similar to facial structures, having sharp claws is only necessary if an animal is going to use these for hunting. Humans have never hunted using our nails and thus evolving sharp claws would be entirely unnecessary and quite a burden in our social lives. Once again omnivores like pigs or carnivores like anteaters do not have the features associated with their respective groups here.
Length of Small IntestineCARNIVORE: 3 to 6 times body length
HERBIVORE: 10 to more than 12 times body length
OMNIVORE: 4 to 6 times body length
HUMAN: 10 to 11 times body length
This is not an accurate measure for omnivorous pigs whose, “small intestines have an average length of 15 to 20 m”Source. For those of you who aren't entirely familiar with the metric system a pig has a body length a little over one meter.