And we don't really know much about the origin of humans in Tolkien's world --
indeed there is plenty of room for the story of Genesis in Middle-earth, and in
Morgoth's Ring Tolkien implies that the story of Genesis may apply. But
we do know that hobbits were one of many branches of the human race. See
the link at the bottom of the page for specific references, including from the
prologue of
LotR.
________________________________________
"‘I think he was a silly little man,' said Councillor Tompkins. ‘Worthless, in fact; no use to Society at all.'
"‘Oh, I don't know,' said Atkins, who was nobody of importance, just a schoolmaster. ‘I am not so sure: it depends on what you mean by use .'
"‘No practical or economic use,' said Tompkins. . . .
. . .
"‘It is proving very useful indeed,' said the Second Voice. ‘As a holiday, and a refreshment. It is splendid for convalescence; and not only for that, for many it is the best introduction to the Mountains. It works wonders in some cases. I am sending more and more there. They seldom have to come back.'"