When Walt Whitman wrote that he contains “multitudes,” he was probably referring to personal potential. But the 19th-century American poet may just as well have been referring to cells. Cells are both the smallest biological unit that can survive on their own, as well as the building blocks that construct all living organisms. They contain instructions that can produce over 200 different types — each with their own function. Those instructions contain rules about what kind of cells they ca ...read more
Ever since the Industrial Revolution, civilization has been powered mostly by fossil fuels. But what sources of energy did ancient civilizations use, and how sustainable were those?How Ancient Civilizations Harnessed Solar EnergyThe most ubiquitous and renewable source of energy is, of course, the sun. People have long used solar energy — and not just for growing crops. According to Let It Shine: The 6,000-Year Story of Solar Energy by John Perlin, excavations of Neolithic Chinese villages sho ...read more
If breaking a mirror actually brought bad luck, surely the government would have public service announcements regarding reflecting-glass safety. And if tossing salt over the left shoulder after spilling a shaker was truly effective, schools would host regular drills.Superstitions don’t make sense. Yet, many logical people wince if they break a mirror. They avoid the number 13 or hold their breath when passing cemeteries.Social scientists are learning more about the psychology behind superstiti ...read more
We’ve known for some time now that Homo sapiens and Neanderthals, also known as archaic humans, interbred before Neanderthals went extinct around 40,000 years ago. In fact, in some ways, Neanderthals never went extinct because modern humans are still made up of around 3 percent Neanderthal DNA.But many questions still linger around where these two groups got together and what their interbreeding might have looked like.Previous research has highlighted a key migration point for H. sapiens after ...read more
Sometimes, resemblances between parent and child or siblings can be uncanny. Other times, such resemblances can pop up between aunt and niece or grandfather and grandchild. And still, other times, resemblances don’t exist at all.One child may look like one parent, and their sibling may look like the other parent. Sometimes, certain facial traits seem to jump from one generation to the next repeatedly.All of these outcomes lead us to wonder what impacts facial features. What part of our DNA is ...read more