"Wait, back up," Dana texted me the next morning. "You said Sapiens like it's a species name. Were there other kinds of humans?"

I called her. This part of the book had shaken me too.

"At least six," I said. "Maybe more. A hundred thousand years ago, the planet had several human species living on it at the same time."

"Six kinds of humans."

"Neanderthals in Europe. They had bigger brains than us, bigger muscles, and they handled ice age cold better. Denisovans in Asia. And on one Indonesian island, humans about a meter tall. Scientists nicknamed them hobbits."

"Real hobbits."

"Real hobbits. Homo floresiensis. Small island, small food supply, evolution shrank them."

"So where did everybody go?" Dana asked.

"That's the dark part. We showed up."

I walked her through the timeline the way Harari lays it out.

"Did we kill them?" she asked.

"Harari gives two theories. One is merging. We interbred, and they got absorbed. There's evidence for that. People outside Africa carry a small slice of Neanderthal DNA today, around one to four percent."

"So I'm a little bit Neanderthal."

"Probably. The other theory is replacement. We outcompeted them for food, or worse. Maybe both happened. Either way, everywhere Sapiens arrived, the other humans stopped existing."

"That's grim."

"It gets grimmer. It wasn't only our cousins."

I told her about Australia. Sapiens reached it about 45,000 years ago. Within a few thousand years, the giant animals were gone. Marsupial lions. Two ton wombats. Flightless birds twice the size of an ostrich.

"Maybe it was climate," Dana said. "Climates change."

"Harari answers that. Those animals had survived plenty of climate swings before. What was new was us. And the same pattern repeats. Humans reach the Americas about 16,000 years ago. Soon after, the mammoths, the giant ground sloths, the sabertooth cats, all gone."

"Same story, different continent."

"Every continent. Harari calls Sapiens an ecological serial killer. The big animals had evolved with no fear of us. They learned too slowly. We were the deadliest species in the history of the planet before we invented the wheel."

"Hold on," Dana said. "The wheel came later?"

"Way later. This is all Stone Age. Spears and fire. That's the unsettling part. It didn't take technology. It just took us."

"So the moral is, we've never been harmless," she said.

"That's Harari's point. People imagine a golden age when humans lived in balance with nature. The fossil record says the first wave of extinctions started tens of thousands of years ago, and we drove it. We didn't fall from grace. There was no grace."

"Okay," Dana said. "What do I do with this one? I can't undo a mammoth."

"You can drop the fantasy that harm only started with factories and plastic. Harari says knowing our record should make us more careful, not less. We are now doing to whales and rhinos what we did to the mammoths, and this time we can see it happening."

Try this: this week, notice one story you tell about "the natural way things used to be." Check it against evidence. Honest history beats a comforting myth, and it changes what you protect.

Dana went quiet for a moment. Then she asked the right question.

"But how? You said it yourself. We were the weak ones. Smaller than Neanderthals, slower than lions. What let one scrawny ape wipe out everything in its path?"

"The lie," I said. "The one that lives in our heads. That's chapter three."