History Plant-based diet

1 history

1.1 paleontonoly
1.2 modern herbivores , mild omnivory
1.3 humans

history
paleontonoly

although herbivory (reliance on diet entirely of plants) long thought mesozoic phenomenon, evidence of found fossils show it. within less 20 million years after first land plants evolved, plants being consumed arthropods. herbivory among four-limbed terrestrial vertebrates, tetrapods developed in late carboniferous (307 - 299 million years ago). tetrapods large amphibious piscivores. while amphibians continued feed on fish , insects, reptiles began exploring 2 new food types: tetrapods (carnivory) , plants (herbivory).

carnivory natural transition insectivory medium , large tetrapods, requiring minimal adaptation. in contrast, complex set of adaptations necessary feeding on highly fibrous plant materials.

modern herbivores , mild omnivory

quite often, herbivorous creatures eat small quantities of animal-based food when becomes available. although trivial of time, omnivorous or herbivorous birds, such sparrows, feed chicks insects while food needed growth.

on close inspection appears nectar-feeding birds such sunbirds rely on ants , other insects find in flowers, not richer supply of protein, essential nutrients such vitamin b12 absent nectar. similarly, monkeys of many species eat maggoty fruit, in clear preference sound fruit. when refer such animals omnivorous or otherwise, question of context , emphasis, rather of definition.

humans

humans, specifically, omnivorous, capable of consuming wide variety of plant , animal material. fossil evidence such wear patterns on teeth of hominids such robust australopithecines , homo habilis indicate opportunistic omnivores, subsisting on plant-based diet, supplementing diet meat when possible.

some nutritional experts believe hominids evolved eating meat result of huge climatic changes took place 3 4 million years ago, when forests , jungles dried , became open grasslands , opened hunting , scavenging opportunities.