The first sheep were tamed in the Zagros-mountains in Iran 11 000 years ago and were selected and bred for their different attributes early on. Already 4000 years ago in Babylon sheep were classified according to which animals gave the best meat or the most wool.

The British became famous for their wool, but towards the end of the 1700s Spain had developed a breed with unprecedented wool-quality: The merino. Penalty by death was the threat to anyone who exported this breed. The Norwegian breeds have changed a lot since the first tame sheep came here over 3500 years ago.

Spæl-sau (the Norwegian variation) has been bred with the Icelandic spæl-sheep to enhance meat quality.
Wool-quality is more “inheritable” than other “qualities” including meat-quality. But there is a negative correlation between enhanced meat quality and wool quality (which explains the “hunger-fine” fibers from Australian merino). One has therefore focused on increasing the meat weight and keeping the wool stable.

“Combination breeding” where very different breeds are bred to ensure some of their inherent best attributes is called “synthetic populations” (ironic!). The breeding-aims are then very specific.
So-called “livestock-breeding” which is very usual in other countries, where the off-spring is not used in further breeding but slaughtered, has had good results for improving meat quality in Norway, but negative results on wool quality. With the very unique mix of bottom-wool and cover-wool on the spæl-sheep it is a clear breeding-goal to keep up the quality of this wool. (If, as the author implies, organic sheep-farming will become increasingly important and the need for breeds that are self-sufficient, sturdy and can take care of their lambs without supervision, it sounds like older breeds will gain in popularity, like the spæl-sheep and the wild-sheep.)
(Author: Ingrid Olesen “Sauavl” in ”Saueboka” pp 215-253)