Well the answer to that is, well, EVERYONE! You may not know it, but being part of a symbiotic relationship is a daily thing. Humans are involved with every symbiotic relationship, mutualism, commensalism, parasitism, amensalism, competition, neutralism, all of them. Some examples of what humans do as a part of symbiosis is when you swat a fly and kill it, that is a form of parasitism. When you run through you mom's garden, you kill the plants, that is a form of amensalism. When you breath, you breath out carbon dioxide and the plant takes in the carbon and give out oxygen for us to breathe. Which is a form of mutualism. When you fall into a rosebush, you hurt the bush and the bush hurts you, that is a form of competition. When your garbage is put in the garbage dump seagulls eat you leftover food, which is a form of commensalism.

Just like symbiosis, everyone is is involved in a food chain. We are the consumers. Humans are part of each type of consumers, some are primary, some or secondary, and some or both, which are ombnivores. Some examples what humans do as part of food chains is when you eat a salad as a part of your new diet, that is a form of being a primary consumer. When you eat steak for you older brother's graduation party, that is a form of being a secondary consumer.