Co-Evolution of Humans and Plants

How do you interact with plants? ? Why do you interact with plants?

brussel sprouts

We respond to a spectrum of sensory effects

  • visual – pigments
  • taste – spice
  • smell – aromatic oils
  • effect – pharmacologically active

Evolutionarily speaking, it remains unclear whether pharmacological use of plants by humans was more prevalent before or after the development of agriculture led to cultivars with reduced biological activity compared to the wild types. Dr. Fatimah Jackson, at the University of Maryland, College Park, argues succinctly that cultural evolution – driven by language – became the driver influencing the extent of human interaction with plants. Dietary preferences are central to how cultures self identify and define. According to Daniel Moerman at the University of Michigan, Native Americans used plants in a 5:1 ratio as medicine and food. Over time humans have learned how to limit their exposure to toxic plants. I imagine a group of early humans going out as a group and asking ‘Mikey’ to try the plant first. If he lived, ‘Mikey’ discovered how to modifying plants’ palatability, nutrition, toxins and to amplify beneficial effects through various means – extraction, heating, drying, and fermentation to name a few. What examples exist from your own cultural heritage of unique use of plants and their chemistry?

Is this a form of co-evolutionary symbiosis between humans and plants? I would argue that humans have had profound effect on the genotype and phenotype of cultivated plants, while plants have provided nutrition, medicine, and the early stimulus for our enzymatic detoxification system and possibly for language development in the brain (synaesthesia – discussed in a future post).  Dietary exposure to continuous low levels of plant mutagens would certainly effect mutation rates or genetic drift. I would highly recommend an article by Dr. Jackson on human-plant-parasite triads as evidence for coevolution.

Consider the next you avoid eating your bitter tasting brussel sprouts – if you don’t eat them, are you de-evolving?