Why do cats meow but lions and tigers roar? So as far as I know the cat animals are related to each other by evolution. (Please correct me on this if I am wrong?) How come the big cats; lions, tigers et.c. roar but smaller cats like house cats meow? Has the evolution of meowing contra roaring been backtracked? Is it possible to tell from the anatomy of a cat and a lion what differences cause the meowing and the roaring? Is there some peculiarities in the design of their voice boxes which cause the differences in sounds?

They have different vocal cords, differently-shaped pharynx. I would imagine that is all that explains the difference in sound. As to mewing versus roaring, the vocalizations you reference are not applied to similar sithations. I wonder if there are videos of baby lions mewing or making similar sounds to get their monther's attention?