I see no reason to assume economic systems must map to physical systems or else must serve a biological imperative to be considered valid. That seems an odd requirement to have. There is no system in our bodies regulating our cells which has strong parallels to capitalism either.
Also, you're mistaken in assuming that cooperation doesn't exist in socialism (I'm going to use the term "socialism" here to refer to the more broadly defined concept rather than "communism" specifically, although to some people it's a distinction without a difference.) Broadly speaking, the entire goal is communal ownership and distribution of resources, particularly of the means of production so that workers own the rights and profits of their labor.
Animals and biological systems do use common resources and cooperate, but they don't tend to form corporate structures to exploit those resources for profit, so the thesis that nature and physics are more capitalist than socialist seems designed to beg the question for an already capitalist worldview.
Also, you're mistaken in assuming that cooperation doesn't exist in socialism (I'm going to use the term "socialism" here to refer to the more broadly defined concept rather than "communism" specifically, although to some people it's a distinction without a difference.) Broadly speaking, the entire goal is communal ownership and distribution of resources, particularly of the means of production so that workers own the rights and profits of their labor.
Animals and biological systems do use common resources and cooperate, but they don't tend to form corporate structures to exploit those resources for profit, so the thesis that nature and physics are more capitalist than socialist seems designed to beg the question for an already capitalist worldview.