Not many of us can separate the sheep from the goats. Those who appear bright of course are thought to be goats, while sheep are frequently considered as people who willingly follow and are just not quite the full shilling! The time when sheep really separated from the goat genus, 4 million years ago, has now been established with the publication of the full sheep genome. 99% of the genome is found on the 26 autosomes and the X chromosome.
The International Sheep Genome Consortium, led by Yu Jiang of Yangling University and Kunming Institute of Zoology, and personalities from Shenzhen, Edinburgh University and the Roslin Institute nearby (don't forget Dolly!), Utah State University the French Institut National de la Recherche Agronomique, Otago University, Washington State University, King Abdulassiz University, KSA, , Copenhagen University, thee European Molecular Biology Lab., and many other US, Chinese, Australian and New Zealand institutions publish the genome in the journal Science as - "The sheep genome".
Of the 7 current species of sheep, only Ovis aries is considered the domestic sheep, descended from the European mouflon,Ovis musimon. The meat, milk wool and even hair/pelts (from hair-sheep) from millions of individual animals have provided for the human species longer than almost any other species. The rumen of sheep, in the same way as that of the bovines or cattle, manipulates the ligno-cellulose from grass digestion in highly developed ways, seemingly using keratin cross-linking genes in the evolution of the organ.
The other smaller parts of the sheep "stomach" are the reticulum, the omasum and the abomasum. From the genome, fat metabolism was also found to interact in wool synthesis, creating several new lines of research for those involved in the huge agribusiness that makes up sheep farming at the moment.
Watch this space for more on the ovine, bovine and the capricornian (if that astronomical word can be used here!) evolutions and what we can make of this new knowledge of their intimate genetic secrets.