These diagrams show genetic distance between human populations that has built up for about 70,000 years, give or take. Australians isolated from everyone else the earliest, but they never speciated. Africans have the most diversity and are very distant for everyone else. But there is plenty of gene flow between all populations. According to Bill Nye, if a Scandinavian with the whitest skin of humanity makes a child with an East African with the blackest skin of humanity then that child will not be considered a mixed species, just a normal human with no complications.
We technically don’t even have races like chimpanzees do. We have demes, like races but with more gene flow between them.
If there is another species it would be undiscovered. Every group we have found we tested their genes and all groups can interbreed with all other groups.
There is a complete examination and answer to this question at:
The Truth About Human Species .
What is explained there is that all the "species" of human described now or in the past 5-million years or so are all one species (they could potentially interbreed). These "species" are best described as Land-races (eg Homo "Neanderthal").
It's also explained there why humans differ essentially from the higher-ape species. Humans have 23 pairs of chromosomes, all the rest have 24 pairs.