From the article, it's not evolution. It's due to changes in weaning habits from industrialization, poor indoor air circulation, and lack of chewing solid foods

From the article, it's not evolution. It's due to changes in weaning habits from industrialization, poor indoor air circulation, and lack of chewing solid foods as babies such that the jaw doesn't develop properly - when the jaw fails to develop properly, it makes it less easy to sleep with proper tongue posture pressing at the roof of the palate. This tongue pressure is partly responsible for widening the palate during development, and then proper nasal breathing during sleep encourages the airways to develop properly. When mouth-breathing, these nasal passages degenerate (or fail to develop properly) in a positive feedback loop that further reinforces the issues, including poor sleep. Moral of the story? Wean your children later, don't use pacifiers, feed them solid foods once they're coming off of breast milk, and open the windows in your house. Also, if your child develops picky eating habits, poor attitude, sleep, or other behavioral issues, look into whether anatomical issues might be at the root of it.