5 Most Incredible Discoveries of the Week

A strange fact to keep in mind when being chased by a crocodile and an important find about the origins of the first Americans make the list:

• Crocodiles Can Climb Trees: As far as discoveries go, this is a somewhat terrifying one, assuming one has a healthy respect for crocodiles on the ground: They can climb and perch in trees. And they can really climb, with researchers spotting them more than a dozen feet from the ground.
• Infant's DNA Pinpoints Origins of First Americans: The DNA from a single infant is shining a light on the true origins of the first Americans. The headline-generating research relies on the DNA of a child buried roughly 12,600 years ago in what is now Montana, and establishes that the first North Americans were born to humans who came to the New World from Asia.
• New Fossil Find One of History's Greatest: Researchers in Canada have made an extraordinary find: a vast collection of fossils that offer an in-depth look at prehistoric life. The site in Kootenay National Park may end up being one of the richest such troves ever found.
• Scientists: We've Found Amazon River's True Source: It's an argument that's persisted for nearly four centuries: Where does the Amazon River begin? Researchers now say it's a different river in Peru than is commonly believed, a finding that would make the Amazon even longer.
• Crazy Ants Have Secret Weapon in Insect War: So-called "crazy ants" are fighting for territory in the US with fire ants, and it turns out they've got a remarkable advantage: a built-in antidote to the venom of their enemy. The trick could have big implications for the Southeast.

Click for more discoveries, including a study that says raindrops aren't shaped like tears after all. (More discoveries stories.)