Sponges are filter feeders with no sophisticated digestive system, a consumption method that absorbs less oxygen—and may have made the squishy creatures central to early life on Earth.
Inside Higher Ed
Fighting Words? A professor compared Hamas to a rabid pit bull. Free speech couldn’t protect him from student vitriol.
What Happened at Slate This Week? Alison Griswold describes her experience reporting on the Germanwings tragedy.
Could Better Psychological Testing Prevent a Tragedy Like the Germanwings Crash? Probably not.