Why does infection with bacteria or viruses make you feel sick? Prof. Guy Shakhar and Dr. Keren Shakhar have proposed that your symptoms are not just a byproduct of your body’s attempt to get rid of the infection. It is your genes’ way of ensuring they are passed down. The long and short of their argument is that the malaise, loss of appetite and lethargy are all ways of isolating you from your social group – so that your kin, who carry many of your genes, are not infected as well.
That means we share an evolutionary adaptation with such organisms as bees that go off to die far from the hive…