Wealhtheow’s Reviews > Pathogenesis: A History of the World in Eight Plagues > Status Update

Rome's baths didn't involve soap, sewage system just carried around bacteria, human waste wasn't composted or processed before being spread on farms, lived in close quarters: several huge plagues that weakened the empire

.>1500 genes in humans' innate immune system come from the time humans took up settled agriculture. Agricultural societies had more babies but also more diseases: the proportion of child and adolescent skeletons increased markedlyw

Many current diseases caused by neolithic pathogens: Hep B, Yersinia pestis, tuberculosis, measles. Then polio and mosquito borne diseases

90% of microorganisms tested from bacteria in feces can produce neurotransmitters like dopamine or serotonin. This ability is unique to bacteria that live in the bodies of animals; microbes have evolved to create chemical messengers that allow them to communicate with/influence their hosts. People w/ depression lack Coprococcus & Dialister but those are common in healthy people's guts

100-200 million years ago, a retrovirus infected a sperm or egg cell, the infection created the placenta which is a temporary organ that attaches to the uterus, doesn't provoke immune response from maternal system, and allows live births instead of eggs. The gene for placentas is almost identical to gene in retrovirus that produces proteins to attach to cells without triggering an immune response.