There is nothing more fundamental about our relationship with Nature than the species we eat.
One evening, while trying to discern exactly what was in the bean casserole my traveling wife had kindly left in the fridge, I wondered: What is the biodiversity of my diet? How many plant and animal species do I consume regularly? And where did they come from?
Later, I compiled a species list from one typical day for four meals: breakfast (cereal and toast), lunch (yogurt and a wrap), afternoon snack (cookie and tea), and dinner (scallops, broccoli, salad, and a brownie). Then, using food labels and knowledge of where I bought the food, I tracked down their origin and ecological niche. I looked up scientific names and kingdoms in the Integrated Taxonomic Information System. I knew where the local food came from, and for other items, where the food label did not specify the source, I determined foreign ones by knowledge of what does not grow in the U.S. (e.g., cacao) and presumed the rest were of U.S. origin.
I calculated that in 24 hours, I ate 53 species spanning four biological kingdoms and five continents.
If variety is the spice of life, we Homo sapiens are the spiciest of species. Our flexibility to change food sources and our ingenuity in finding and processing food has given us a broader diet than any other species. That allowed our ancestors to expand across almost the entire land area of Earth. We developed agriculture and ways of preserving and transporting food. We developed ways to process food sources that would otherwise be inedible. We have reached into almost every corner of Earth for food. Our technology and globalization have brought more species of food to more human societies than at any point in the 200,000 to 250,000 years our own species has been on the planet.