The global-scale relationship between plants, people and the planet has culminated in recent times by the recognition of a new geological epoch, the Anthropocene. This is an acknowledgement of human influence on the global cycling of biogeochemicals crucial to all life, and which pass through plants, notably, water, oxygen, carbon dioxide, nitrogen, and phosphorus.
Historically, there is the pre-human influence of plants on the terrestrial conditions that would subsequently affect human lives. Then, there was the evolutionary impact of plants on human biology, plant-dependent changes in anatomy, physiology, and psychology. Over the last 15,000 years or so there have been changes that occurred as a result of human cultural evolution – the increase in complexity of human social organization.
Human cultural evolution (discussed in other articles) consists of four phases: Natura, Agraria, Industria, and the current phase of Informatia. With the exception of Informatia, these are phases whose increasing complexity of social organization has been totally conditional on plant energy – firstly, that of wild plants (Natura), then cultivated plants (Agraria), followed by the addition of fossil fuels (Industria).
c. 3.5 billion – Addition of oxygen to the Earth’s atmosphere by photosynthetic cyanobacteria as a waste product. At first rapidly absorbed by organic compounds and dissolved iron, it produced layers of iron oxide on the ocean floor until about 2.3 billion years ago when excess free oxygen began to accumulate in the atmosphere during the Great Oxygenation Event.
2 billion – protist-like organism as the common ancestor of animals and plants – with shared common biochemical pathways
Hominin evolution – development of plant-induced aspects of anatomy, physiology, and psychology including: stereoscopic and colour vision; omnivore dentition; ?bipedalism; diet and digestion associated with the comsumption of plants; taste differentiation of sweet, sour, and bitter; biophilia