Through intensive breeding, humans have pushed breeds such as pug dogs and Persian cats to evolve with very similar skulls and “smushed” faces, so they’re more similar to each other than they are to other dogs or cats.

New research questions the evolutionary history of some of our most peculiar mammals.

The study found that bird species who nest in tree cavities have independently evolved heightened aggression across lineages, particularly in females. 

Virginia Tech's Bryan Hsu and graduate student Hollyn Franklin built a model that allows them to diminish phage communities from a mouse gut microbiome — and then bring them back — without affecting the bacteria. On a test run of their model, researchers found evidence that phages may increase gut bacteria’s sensitivity to antibiotics. Their results were published April 28 in the journal Cell Host and Microbe.