If a lion is killing the weakest members of your herd it is natural to want to kill the lion. But that victory can be a defeat for the health of herd. I wonder

If a lion is killing the weakest members of your herd it is natural to want to kill the lion. But that victory can be a defeat for the health of herd. I wonder if a scientist in a lab somewhere decided that a disease that takes the old and infirm while sparing the young was a wonderful species of lion, a gift to the herd to be released into the wild.