So if we move some people from Indiana over to a remote region of the Mojave desert, they will "speciate" into monkeys?
No...cauliflowers./sarc
The first step toward speciation is formation of sub-species or races. Humans do not all look alike because over tens of thousands of years different populations--when isolated from each other--begin to accumulate genetic changes that do not happen in other populations. Koreans do not look like Somalians because their ancestors have been separated for tens or perhaps hundreds of thousands of years.
If the isolation continues for millions of years, new species could develop...that is the theory that is supported by many facts. But: can we watch a new species be created? No...we don't live that long.
I hope this was helpful.