How gliding animals fine-tuned the rules of evolution
A study of gliding animals has challenged the idea that evolutionary innovations—adaptations that bring new abilities and advantages—spur the origin of other new body types and other characteristics in descendent species. The research, undertaken by evolutionary biologists at UNSW Sydney and universities in the US and Spain, examined the key innovation of gliding in two types of gliding animals: 'flying' dragons (family Agamidae) and 'flying' squirrels (family Sciuridae), both common to forests in Southeast Asia. "Gliding Dragons and Flying Squirrels: Diversifying versus Stabilizing Selection on Morphology following the Evolution of an Innovation," published in The American Naturalist 195, no. 2 (February 2020), confirms previous assumptions that gliding animals originated from arboreal ancestors and likely arose as a means of escaping predators some 25-30 million years ago.