Origin of the domestic dog as the Tibetan people. A population genetic analysis then showed a significant convergence between humans and dogs in Tibet. Like the Tibetan people, Tibetan mastiffs appear to have derived these benefits partially from the EPAS1 gene, acquired through introgression. In 2015, a study found that when dogs and their owners interact, extended eye contact (mutual gaze) increases oxytocin levels in both the dog and its owner. As oxytocin is known for its role in maternal bonding, it is considered likely that this effect has supported the coevolution of human-dog bonding. One observer has stated, "The dog could have arisen only
Ticks of domestic animals as an adult on another cow in a three-host lifecycle. Furthermore, this tick commonly feeds as a three-host tick with larvae, nymphs, and adults feeding on separate individual dairy cows confined to cattle housing in zero-grazing systems. "Argas persicus", the fowl tick, is a major pest of poultry birds (see Gallery below for photograph). The tampan ticks within "Ornithodoros moubata" complex of species infest domestic pigs and also feed on humans. "Ornithodoros savignyi" is often found in large numbers at enclosures where camels and cattle are herded. Many species of argasid soft ticks are adapted to live in the nest