Origin of the domestic dog that was the most divergent group. The study found that the skulls of the "Goyet dog" and the "Altai dog" had some dog-like characteristics and proposed that the may have represented an aborted domestication episode. If so, there may have been originally more than one ancient domestication event for dogs as there was for domestic pigs. One theory is that domestication occurred during one of the five cold Heinrich events that occurred after the arrival of humans in West Europe 37 000, 29 000, 23 000, 16 500 and 12 000 YBP. The theory is that the extreme cold during
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