There are and have been very many interesting and learned theories about how mankind developed and to what purpose and how this might have led on to later civilisations.
But we have not been alone and our transition from hunter gatherer bands into settled groups and later tribes etc. has been in company with various forms of animal life. This article tells us about the goat factor.
Dogs are much favoured and cat lovers etc. will always argue their case, then there are the cattle and horses.
But what if mankind's progress in the early millennia in fact depended on goats and pigs and their domestication?
Food for thought.