Biologists dated the emergence of vocal sounds to 400 million years ago by studying the gruntings of male toadfish and midshipmanfish, both of which hum deeply to attract females and growl threateningly to ward off rivals.
Biologists dated the emergence of vocal sounds to 400 million years ago by studying the gruntings of male toadfish and midshipmanfish, both of which hum deeply to attract females and growl threateningly to ward off rivals.