Pelops had brought the Chosen to Argos as part of an experiment in human physiology and evolution using nano-technology. A Goa'uld nano-virus used artificial self replicating mechanical nanocites to accelerate the human life span by approximately 250 times. One day would equal approximately one year, and the average human lifespan would be one hundred days. The virus was carried in the blood and passed on through intimate physical contact. Kynthia unwittingly passed the virus on to O'Neill, who aged to the equivalent of 90 years in a few days.
A transmitter signal concealed within the statue of Pelops triggered the virus and controlled the inhabitants' waking and sleeping, as well as the aging process. When the transmitter was destroyed, the nano-virus no longer functioned, the nanocites were destroyed by the immune system, and aging returned to normal. A similar type of nano-technology was used to accelerate the initial growth of Shifu, the Harsesis, as well as Anna, the human-Goa'uld hybrid created by Keffler.
Cross Reference: Alekos, Anna, Argos, Argosians, Hazmat, Kynthia, Nano-Technology, Pelops, Thetys
Episode Reference: Brief Candle, Absolute Power, Resurrection