Researchers have described remarkably well-preserved tissue discovered inside a salamander fossil. The fully intact muscle tissues also had blood-filled vessels, and they had not been mineralized like most fossils.

David Queller and Joan Strassmann, evolutionary biologists at Rice University, recently proposed a new way to describe what makes an organism a unified whole. They defined an organism as an entity made up of parts that cooperate well for an overall purpose, and do so with minimal conflict. But how do parts like these get together, and where does purposeful behavior come from?

“Darwin’s finches” are a variety of small black birds that were observed and collected by British naturalist Charles Darwin during his famous voyage on the H.M.S. Beagle in the early 1800s. Years later, Darwin argued that subtle variations in their beak sizes supported his concept that all organisms share a common ancestor (a theory known as macroevolution).

Research has shown that humans like to help, even before they are old enough to have been taught how to do so. This innate characteristic distinguishes humans from their supposed closest evolutionary family member, the chimpanzee, which doesn’t demonstrate the same altruistic behavior.

Museums and textbooks often use artistic renderings to estimate what a fossilized animal or plant may have looked like when it was alive. These images by “paleoartists” put flesh and faces on skeletal structures, and they can influence public perception of early human history more than the actual science—particularly in regards to human evolution.