I was reading the definition of 環境:
取り囲んでいる周りの世界。人間や生物の周囲にあって,意識や行動の面でそれらと何らかの相互作用を及ぼし合うもの。
I understand the first sentence it as: "world that is a surrounding-area" or like "the place around us".
I have, however, problems with understanding what the meaning of 及ぼし合う is:
人間や生物の周囲にあって,意識や行動の面でそれらと何らかの相互作用を及ぼし合うもの。
I know 及ぼす means "to exert (influence)", but with 合う, I know that the action is done with someone. On Yahoo, I found a definition of it 互いに影響しあう. With whom/what is this 及ぼし合う done with?