Other researchers have argued that all of the Botai horses were wild, and that the horse-hunters of Botai hunted wild horses on foot. As evidence, they note that zoologists have found no skeletal changes in the Botai horses that indicate domestication. Moreover, because they were hunted for food, the majority of the horse remains found in Botai-culture settlements indeed probably were wild. On the other hand, any domesticated riding horses were probably the same size as their wild cousins and cannot now be distinguished by bone measurements. They also note that the age structure of the horses slaughtered at Botai represents a natural demographic profile for hunted animals, not the pattern expected if they were domesticated and selected for slaughter. However, these arguments were published prior to the discovery of a corral at Krasnyi Yar and mats of horse-dung at two other Botai sites. A study in 2018 revealed that the Botai horses did not contribute significantly to the genetics of modern domesticated horses, and that therefore a subsequent and separate domestication event must have been responsible for the modern domestic horse.