regarding the 'proper chickens' question, this is alarming: "Muir et al. (2008) were the first to assess the genetic diversity of several inbred lines of chicken (n = 2580) using a commercial SNP genotyping array. They showed that more than 50% of the ancestral genetic diversity was lost in the commercial lines compared to the experimental lines and standard breeds. " https://onlinelibrary.wiley.com/doi/full/10.1111/age.13091