A really interesting new study is summarised by Science Daily.
[This new study] show that political and economic factors were most important in determining the species distribution and body size of ancient livestock. During the Late Bronze Age and Late Antiquity, when political systems were more fragmented and food production was focused more on local markets, livestock choice was more dependent upon local environmental conditions. But during the later Iron Age and the time of the Roman Empire, the demands of a pan-Mediterranean market economy favored more changes in livestock use independent of environmental factors. Zooarchaeology is thus a vital source of information for understanding political and economic changes through time.
Visit the story’s page here.