"Meanwhile, we Homo sapiens traveled out of Africa en route to everywhere, encountered the Neanderthals in Europe, had sex with them, and, directly or through competition for resources, exterminated them. Some 30,000 years later, we rediscovered them, via their remains, in a cave in limestone cliffs in a valley in Germany. That cave no longer exists. Those cliffs no longer exist. We quarried the limestone, smelted it with coke and iron ore, and converted it to steel.
"What species does this? Only ours. Somewhere along the line, thanks to some twist in that 0.3 percent of uniquely human DNA, we became the sort of creatures who could level cliffs and turn stone to steel; 'the sort of creature,' Kolbert writes, 'who could wipe out its nearest relative, then dig up its bones and reassemble its genome.'”