> The energy demands of flight are so great that cells in the body break down and release bits of DNA that are then floating around where they shouldn’t be. Mammals, including bats, have ways to identify and respond to such bits of DNA, which might indicate an invasion of a disease-causing organism. But in bats, they found, evolution has weakened that system, which would normally cause inflammation as it fought the viruses.
Bats have lost some genes involved in that response, which makes sense because the inflammation itself can be very damaging to the body. They have a weakened response b…