Humans first learned to regularly consume the milk of other mammals following the domestication of animals during the Neolithic Revolution or the development of agriculture. This development occurred independently in several places around the world from as early as 9000–7000 BC in Mesopotamia to 3500–3000 BC in the Americas. The most important dairy animals—cattle, sheep and goats—were first domesticated in Mesopotamia, although domestic cattle had been independently derived from wild aurochs populations several times since. From there dairy animals spread to Europe (beginning around 7000 BC but not reaching Britain and Scandinavia until after 4000 BC), and South Asia (7000–5500 BC).