It is reported that the following part of the Book of Genesis was discovered in the Dead Sea Scrolls. If authentic, it would shed light on the question, "Where do pets come from?"

And Adam said, "Lord, when I was in the garden, you walked with me everyday. Now I do not see you anymore. I am lonesome here and it is difficult for me to remember how much you love me."

And God said, "No problem! I will create a companion for you that will be with you forever and who will be a reflection of my love for you, so that you will know I love you, even when you cannot see me. Regardless of how selfish and childish and unlovable you may be, this new companion will accept you as you are and will love you as I do, in spite of yourself."

And God created a new animal to be a companion for Adam. And it was a good animal. And God was pleased.

And the new animal was pleased to be with Adam and he wagged his tail. And Adam said, "But Lord, I have already named all the animals in the Kingdom and all the good names are taken and I cannot think of a name for this new animal."

And God said, "No problem! Because I have created this new animal to be a reflection of my love for you, his name will be a reflection of my own name, and you will call him DOG."

And Dog lived with Adam and was a companion to him and loved him. And Adam was comforted. And God was pleased. And Dog was content and wagged his tail.

After a while, it come to pass that Adam's guardian angel came to the Lord and said, "Lord, Adam has become filled with pride. He struts and preens like a peacock and he believes he is worthy of adoration. Dog has indeed taught him that he is loved, but no one has taught him humility."

And the Lord said, "No problem! I will create for him a companion who will be with him forever and who will see him as he is. The companion will remind him of his limitations, so he will know that he is not always worthy of adoration."

And God created CAT to be a companion to Adam. And Cat would not obey Adam.
And when Adam gazed into Cats eyes, he was reminded that he was not the supreme being. And Adam learned humility. And God was pleased. And Adam was greatly improved. And Dog was content. And Cat did not care one way or the other.