The molecular clock theory posits that genetic changes happen steadily and gradually, offering a reliable means for peering into the past and theorizing when complex life first emerged. However, there ...

Understanding the material basis of adaptive evolution has been a central goal in biology dating back to at least the time of Darwin. One focus of current debates is whether adaptive evolution relies ...

He lived hundreds of thousands of years ago, eking out an existence in what is today central China. Sporting a squat neck and a big brain, he likely wielded tools made of stone and hunted or scavenged ...