Most peppered moths used to be grey with dark spots, but have evolved to be mostly black. This is because pollution from the Industrial Revolution threw soot on the trees causing them to look black. This gave the black moths camouflage from predatory birds meaning they survived and reproduced. By survival of the fittest, the peppered moths became black like the trees.
When you drag something, you are usually pulling it across a surface, which means there is contact. Same with when something springs or bounces and with friction.
