Luristan bronze by most families. Taking the groups in what is now generally considered to be their broad chronological sequence, the first are the "animal finials", with two rampant confronted animals, generally a pair of large-horned ibex (or goats or mouflon sheep) or felines, facing each other with a central tube or open rings (formed at the junctions of their front and hind feet) between them. The bezoar ibex ("capra aegagrus aegagrusis"), the local wild species of goat or ibex, was already domesticated millennia before; it has large curved horns with knobbly ribs. Compared to later types, the animals are more naturalistic,
Dmitry Belyayev (zoologist) also been of great interest to Darwin. It was recognized that domesticated animals differ in several ways from their wild counterparts, but it was not known what principle of selection had guided the Neolithic farmers who had first domesticated these species thousands of years ago. Belyayev's hypothesis was that "all domesticated species had been selected for a single criterion: tameness." Belyayev further theorized that this attribute "had dragged along with it most of the other features that distinguish domestic animals from their wild forebears, like droopy ears, patches of white in the fur and changes in skull shape." In other