What is Kipling trying to say about heredity versus environment in his stories about Mowgli?

Family and loyalty to family is a theme running throughout the book. From the moment Mowgli wanders into Mother and Father Wolf's cave thru adopt him as their own, Mother Wolf actually favoring him on many occasions. Although Mowgli is a "man cub" his heredity does not interfere with the way he identifies himself as a wolf in the jungle. Nurturing seems to outweigh heredity in the jungle.