We Wrecked the Silkworm (And Deleted Half Its DNA)

The domestic silkworm cannot fly, cannot smell properly, cannot see danger, and can't reproduce without getting paired up by humans. Its wings are structurally normal. It just lost the muscle and neural wiring to ever use them. This is the story of Bombyx mori, a species now so genetically distinct from its wild ancestor that the two are classified separately, just like dogs and wolves. It's a change that happened one basket at a time, for 5,000 years, through a selection process with no laboratory or plan. The silkworm is likely the world's most common domesticated animal. It also might be the one we broke the most.