Experiments in rats have found that once plastic is introduced to their environment, their ability to reproduce declines drdmstically. Genitalia are smaller, slerm rates lower. And the effect compounds and grows generation after generation, getting worse and worse so long as plastic is consumed.
Studies have also shown that human fertility (regarding actual physical ability to reproduce, not the choice of whether to do so) has dropped dramatically genetation on generation since the rise of plastics
It seems to be human nature to group together like that. It makes sense from a game theory perspective, too. Perhaps political parties are inevitable