Question: How do you think humans will have to adapt after we overuse medicines such as penicillin so much that we become immune to it?

Eoin McKinney answered on 6 Nov 2017:

As soon as we start using antibiotics, bacteria start getting resistant. Thats evolution taking place on a small scale – the ‘fittest’ bacteria survive with resistant bugs emerging quite quickly due to high rates of division and mutation. Our immune systems have played this game for millions of years – trying to ‘outwit’ bacteria so they can’t survive in our bodies. Bacteria have spent the same time developing ever-better ways of getting round our defences. There are a few things we can do to make our life easier – avoid getting infections in the first place (vaccines, public health, handwashing etc), developing new antibiotics and limiting resistance to the antibiotics we have are good examples. Using combinations of antibiotics helps as it means bacteria have to evolve resistance to more than one to survive and evolve resistance – the chances of this are much lower. Avoiding giving antibiotics where they aren’t needed is also important – both in farming (farmers use them to stop animals getting infections rather than to treat infections) and by doctors (patients often get antibiotics for viral infections like the cold and ‘flu – antibiotics do absolutely nothing against the virus but sometimes make people feel better as it looks like something is being done to help).