Previously we talked about how early humans outcompeted Neanderthals. One big reason for their success might be sitting right next to you. I’m talking about dogs.

When humans arrived in Europe, they were at the top of the food chain, along with Neanderthals, big cats, bears—and wolves.

Archaeological records suggest that humans soon began to domesticate wolves, which quickly evolved into proto-dogs, and joined the hunt.

The dogs did what they did best—chasing large prey over distance, tiring and cornering them. Man stepped in with spears and arrows to close the deal, sparing dogs the dangerous part of the kill. Then they shared the meat.

Butchering sites for large animals like mammoth would have attracted other carnivores. Scientists believe early dogs also helped keep scavengers away.

Fossilized remains show early dogs were similar to huskies, but bigger. The skeletons show healed broken bones, suggesting a rough hunting life but also care afterward.

By contrast, Neanderthal sites show no evidence of a partnership with dogs.

Humans and dogs became such a dominant hunting force, researchers believe, that they simultaneously eliminated large prey and outcompeted not just Neanderthals but most other large predators.

So the next time you see a dog, give ‘em a big “thank you” belly rub.

They were essential to human success. And with that, they guaranteed their own—and a friendship lasting 50,000 years.