Memes

Well... if you want to get really into anthropology, there's an argument that outsourcing our digestion (via early agriculture) actually made us a lot weaker and dumber. It was social pressure (often explicit enslavement) that forced people into the agricultural lifestyle. But that a booming population powered by cheap, reliable agriculture allowed multitudes to outperform by volume what exceptionally smart and strong but scarce individuals achieved in small tribes.

More advanced forms of sterilization became necessary as populations hit certain critical levels of risk for pathogens and other hygiene problems. And so modern techniques, like vaccination and pasteurization, are really just extensions of this ten-thousand year trend towards urbanization that require health and safety precautions as a condition of our dense population centers.

This wasn't just biological evolution. Our ability to process, transmit, and record information made our species heavily dependent on these technological techniques and the passing down of the instructions to perform them. The health risks are now bound up in our ability to maintain a working, useful library of information and to perform the rituals necessary to keep our food and water sufficiently sterile.