Antibiotic chemicals that kill or arrest the growth of bacteria often have no activity against archaea or eukaryotic parasites. While this isn’t a clinical problem for archaea (there are no described archaeal pathogens!), it certainly is for diseases caused by eukaryotic parasites like malaria. In fact, effective antimicrobials for eukaryotic parasites or archaea are often similar to cancer drugs that arrest the growth of proliferating cells in human bodies.

What similarities are there between an antibacterial drug and a cancer drug? Why would archaea and eukaryotic parasites be killed by cancer drugs, but not by bacterial antibiotics? (Hint, consider how human cells, eukaryotic parasites, archaea and bacteria are evolutionarily related and how this might relate to the cellular machinery targeted by drugs to stop cell growth.)