sentence: Humans are no exception.
sentences_before: The relevance of symbiosis is its frequency and its evolutionary significance. There appear to be no higher plants or animals without symbionts. Those symbionts are of great importance to the larger organisms, who in most cases would be unable to live as they do without their symbionts. Mycorrhiza in higher plants, and gut flora in insects and vertebrates are examples.
concept_name: human
headings: Symbiosis
categories: Ecology Cell biology Evolutionary biology