Specieswatch: how whirligig beetles evolved to occupy an environmental niche

Fossils show species has been around for millennia and evolved to occupy surface of fresh waterWhen alarmed and to avoid predators the whirligig beetle (Gyrinus substriatus) swims rapidly in circles. There are about 700 species worldwide but this 6mm version is the most common in the UK and can be seen in hundreds gyrating on ponds and waterways.The fossil record shows whirligig species have been around for millennia and evolved to occupy a niche in the environment: the surface of fresh water. The beetle's two pairs of eyes, one pair scanning underwater and the other above, are simultaneously checking for prey and predators. Continue reading...