Anyone who doesn't believe that evolution is a valid biological process only needs to look in their medicine cabinet for proof otherwise. We are currently locked in a deadly race of evolution against bacteria, and, on some fronts, the bacteria are defying all expectations and winning.

Ever since the pharmaceutical revolution sparked by Penicillin almost a century ago, scientists have been developing and researching stronger and stronger antibiotics to fight bacteria that grow resistant to the ones they're using. This is because the weaker bacteria are being killed off in droves. In this sense, they aren't growing stronger so much as losing their weaker gene pool. Even if 0.000001 percent of bacteria are antibiotic resistant, if their weaker counterparts are being killed off in large numbers, the more powerful strains of infection become gradually more potent until the weak bacteria aren't enough to dilute the stronger threat. Even if one in 50 bacteria are antibiotic resistant, that's enough to cause a sizable infection in a matter of days.

You've witnessed this war yourself if you or anyone you know has had an antibiotic relapse. If you haven't seen it, you've probably heard of it. A friend gets strep throat or some other minor bacterial illness, and the doctor prescribes an antibiotic for seven days. For the sake of argument, he takes it for five, feels better, and stops. A few days later, he'll start to feel sick again. This is because the regular bacteria have died off, but the stronger, more potent strains of infection have survived, and now those are making their comeback. If he tries to treat this infection with antibiotics, it won't work, because the strain will have evolved resistance. He'll need a stronger antibiotic, which is what makes relapses so much deadlier than the original illness; the stronger antibiotics can sometimes come with deadly side effects of their own, and if the relapse is strong enough, it may not respond to most antibiotics, if any at all.

We live in a world saturated by antibiotics. We take them every time we get sick, we use antibacterial soaps and cleaners in all of our public and private spaces, and, perhaps most foolishly, we douse animals with them in factory farms, meaning that this relapse cycle is taking place in those facilities. Antibiotics are even being found in the food we eat. This means that bacteria around the world are facing the greatest unintentional selective breeding effort in human history, the unintended goal of which is to develop a super-bacteria resistant to all known forms of medicine, and we're not too far from it.

A few months ago, reports of bacteria resistant to "last line of defense" antibiotics began emerging from China, where the antibiotic, supposedly under tight control, was being liberally applied to herds of pigs. Since then, the superbug has been found in other countries, including Malaysia and the United States. The genes from this bug can be transferred between other bacteria as well, meaning that other infections will soon become antibiotic-resistant. This doesn't make bacteria resistant to every drug, just to one type, but other strains of resistance exist and are rapidly spreading.

So, what can you do? Finish full rounds of antibiotics, and don't quit when you simply feel better. Follow the dosage through to make sure all bacteria die, not just the ones that are most vulnerable. That's only if you have to take antibiotics. Make sure you need them, and that there's no alternative before you use them. Think of it like car exhaust and global warming; if you need a car, go ahead and drive one, but using them unnecessarily will increase your carbon footprint and ultimately hurt the environment. You will be playing a small part in fighting climate change by walking to work or taking a bike. The same rule goes for antibiotic resistance. If you need antibiotics, by all means, don't deny yourself the medicine you need. If you don't even know if your infection is bacterial, then wait or get a doctor's opinion. Every bit counts.