The dog blog

Dogs may understand our emotions more deeply than scientists realized. Brain scans show that happy human faces activate regions in dogs linked to higher-level processing and reward, suggesting that smiles carry special emotional significance for them.

Dogs have been shaping—and being shaped by—humans for about 15,000 years, evolving from early partners of hunter-gatherers into an astonishing range of specialized companions. Across the globe, they adapted alongside people to wildly different environments and needs, from powerful Arctic sled dogs and agile rainforest hunters to high-altitude dogs with genetic traits for surviving thin air. Some were even bred for wool, while others played important spiritual or ceremonial roles.

A notorious snake invasion that devastated Guam’s native birds may have succeeded because the reptiles carried hidden genetic advantages. Using advanced long-read DNA sequencing, researchers uncovered more than 19,000 large genetic differences in brown tree snakes, many concentrated in genes tied to immunity and smell. This overlooked diversity may have helped a population founded by only a few snakes survive inbreeding, adapt to a new environment, and multiply to extraordinary densities.

Researchers say a tiny one-eyed ancestor that lived nearly 600 million years ago may have shaped the evolution of every vertebrate eye, including our own. They also found that its ancient median eye lives on today as the pineal gland, which helps synchronize our sleep with daylight.

Scientists discovered ancient wolves on a tiny Baltic island where they could only have been brought by humans, suggesting an unexpectedly close relationship between people and wolves thousands of years ago. Evidence indicates the wolves were fed, possibly cared for, and may even have been managed or selectively bred long before modern ideas of domestication.