Ancon Sheep—a Cautionary Tale
“In 1791, so it seems, a Massachusetts farmer named Seth Wright owned a flock of fifteen ewes and a ram of the ordinary kind. These sheep, as sheep are wont to do, were fond of leaping over the stone walls that fenced them in. Once out on their own, they raided Wright’s neighbors’ fields. So, imagine Farmer Wright’s surprise (and delight) when one of his ewes produced a most uncommon ram lamb, long of body and incredibly short of leg. Sheep like this, Wright correctly deduced, could not jump over stone fences
“So, Farmer Wright culled his normal ram, the short-legged ram’s sire, and bred the short-legged ram to his flock of ewes. The first year only two short-legged lambs were born. However, when he began breeding short-legged to short-legged sheep, the animals began to reliably reproduce their kind. And thus the Otter (later to be known as Ancon) breed of sheep was born.
“Charles Darwin considered Ancon sheep a perfect example of macroevolution. In Origin of Species, first published in 1859, he referred to the Ancon thus, 'It is a rare thing for a striking variety to spring as suddenly as this into existence, and it is singular that the peculiarity should be preserved unmixed in the cross or half-breed; but in other respects it is common-place enough and only represents what men do every day with their cattle, poultry, horses and dogs, and what is done by every nursery gardener in rearing plants. Whenever a breeder sees any peculiarity appear amongst his animals which he considers valuable, he carefully preserves the individual that shows it, and by pairing it with other individuals that manifest a tendency towards it, and selecting such of the offspring as have most perfectly inherited it, he succeeds in perpetuating and greatly improving it.'
“But was it an improvement? Ancons were achondroplastic dwarfs, a type of genetic dwarfism characterized by slow limb growth relative to the rest of the skeleton. Their condition was caused by a mutation that results in the failure of the cartilage between their joints to develop. Numerous other abnormalities existed, including abnormal spines and skulls, flabby subscapular (deep shoulder) muscles, loose leg joint articulations, and badly deviated inward forelegs. Adult Ancons were clumsy cripples that could neither run nor jump like other sheep; that they suffered from crippling arthritis is a given. The breed had so many major health problems that it became extinct decades ago.
“So as the adage goes, ‘It’s not nice to fool Mother Nature’. Should cute, mutated dwarfs happen along, it’s wise to choose not to propagate them. There are scores of breeds of small and miniature livestock available for producers and hobbyists to raise. Let’s do our best to raise animals that enjoy good quality of life.”