Scientists are tracing back the history of dogs using the oldest genes from the species ever studied. Scientists think dogs descended from an ancient population of gray wolves somewhere in Europe or Asia. But exactly when and where this happened remain a mystery. Researchers examined ancient genes from the remains of over 200 dogs and wolves and found that the oldest dated back to about 15,800 years ago. Ancient dogs' lives were closely tied to the movements of the humans they lived with. Scientists can’t paint a picture of exactly what the first dogs looked like, but think they resembled smaller wolves. The new studies were published Wednesday in the journal Nature.

Researchers say the discovery of the oldest known recordings of whale sounds could open up a new understanding of how the huge animals communicate. The recording captured the song of a humpback whale, a marine giant beloved by whale watchers for its docile nature and spectacular leaps from the water. Researchers at Woods Hole Oceanographic Institution in Falmouth, Massachusetts, say it was recorded in March 1949 in Bermuda. The recording predates the discovery of whale song by nearly 20 years. Scientists say the recording is important because it documents whale song during a time when the ocean was quieter.

Thousands of snow geese touch down at a Pennsylvania reservoir each spring, turning sunrise into a loud, swirling liftoff that draws big crowds. A few dozen birdwatchers gather before dawn at the Middle Creek wildlife preserve to catch the moment. After sunrise, the flock suddenly rises from the water's surface, circles and then heads to nearby fields to feed. The state Game Commission says Middle Creek has hosted huge groups of 100,000 or more in recent years. Scientists warn that the geese have grown so abundant that their numbers have damaged breeding grounds in the Canadian Arctic. There are also concerns about avian influenza.

King penguins are adapting to climate change in a way that seems to help them breed successfully, which is unusual. Researchers tracked about 19,000 birds on a sub-Antarctic island chain and found breeding is starting 19 days earlier than in 2000. Wednesday's study links the earlier timing to a 40% jump in breeding success. That's a rarity in the natural world, where warming often means mismatches in timing for species that depend on each other, like bees and flowers. Scientists say the king penguins benefit from being flexible in diet and breeding. It's a climate change success story, but scientists caution it may only be for now.

Ancient linkups may have happened more frequently between female humans and male Neanderthals, according to an new genetic analysis. Scientists know that Neanderthals and humans mated because there is a small percentage of Neanderthal DNA in most modern humans. But they also know that the Neanderthal DNA is not distributed evenly throughout the human genome. Scientists looked at the human genes that got interspersed with Neanderthal ones during an ancient mating event and saw a surprising human fingerprint that told them the explanation may be mating behavior. The new study was published Thursday in the journal Science.