You also see the same thing in bicycles (some very major features of a bike like which wheel was driven, whether the wheels were the same size, etc. varied wildly in the late 19th century), infantry weapons (assault rifles haven&#x27;t fundamentally changed since the 60s), and commercial airliners (these days they&#x27;re all engine-under-the-wing, cruciform tailplane, tricycle landing gear, and the like, but in the early days there was a lot more variety of shape).