Dogs come in all shapes and sizes. We’ve moulded some of them to have large protruding eyes, sloping backs and shortened legs through selective breeding.
What is increasingly clear is that some of the extremes of physical shape, size and appearance seen in many dog breeds damage their health. Despite this, many of these breeds, such as French bulldogs, continue to increase in popularity. In response, the Royal Veterinary College in the UK has issued guidance on ten extreme body shapes prospective dog owners should avoid.
But dogs aren’t the only animals who have suffered the consequences of selective breeding.
Humans have selectively bred animals for centuries. For animals linked to agriculture, selection has resulted in high milk-yielding dairy cows, chickens that lay eggs far more frequently than their forest-dwelling ancestors ever would have, and sheep that grow wool to excess.
The reality for many animals is that intense genetic selection for specific characteristics, whether physical or behavioural can result in serious unintended consequences.
Dairy cows often suffer from crippling lameness. Laying hens have a limited egg output and their life span is substantially less than it otherwise naturally would be - both because selective breeding has reduced........