Sea turtles can have a hard time in the modern world. When hatchlings are born on the beach, they instinctively head toward the brightest part of the horizon. They developed this instinct over millennia because the brightest part of the horizon had always been the ocean, where light reflected off the water. These days, this instinct often leads them astray. In developed areas, they head toward brightly lit beach houses or coastal roads instead.
This is a case of so-called evolutionary mismatch, when traits that evolved in one environment have negative consequences in another. The turtles’ instinct works well in a natural environment, without artificial light. In a man-made environment, it is often fatal.