We ourselves are in-between and so are all other primates, gorillas, bobobos, chimpanzees and orangutans. Evolution is an ever-ongoing process. Do you think evolution will stop with Homo sapiens sapiens? Some survive and flourish, others become extinct.
There are
more than 260 different types of monkeys. They are separated into two major categories: New World and Old World. Google Search, 28-May-2014.
We too are, sort of, old world monkeys.
Homo rhodensis, Homo heidelbergensis, Homo naledi, Homo ergaster, Homo antecessor, Homo neanderthalensis, Homo denisova, Homo floresiensis, did not survive. All were slightly different from us. See the list of lineages here:
Homo - Wikipedia. Interbreeding depends on the distance of lineages between them. We do have neanderthal and denisovan DNA in us. The problem is that either you do not know about biology or are willfully ignoring it.