The word race as biological term applied to all lifeforms comes from the 19th century, where it was used for what is now usually called a subspecies. That is the sense in which I am about to use it now.
The Homo sapiens sapiens race began flourishing just 195 thousand years ago.
Out of the four known races (sapiens, neanderthalensis, denisova, idaltu) of the Homo sapiens species, it is the only one remaining. There have been six other known species (habilis, naledi, ergaster, erectus, heidelbergensis, floresiensis) of the 2.8 million year old genus Homo, each of which has only one race identified in it, except for Homo erectus, of which nine races have been identified.
Of these eighteen races of Homo, or Human, known to have walked the Earth in the past 2.8 million years, only ours, H. sapiens sapiens, remains. So, when Edward James Olmos as his alter-ego Admiral Bill Adama of the Battlestar Galactica (BS-75) said in an appearance with his crew at the UN that there is only one race, the human race (and so say we all, or at least we should), he was literally as well as rhetorically accurate.
That’s why I say that I am a Terran, a citizen of Earth. The whole world is my home and all its people my brothers, sisters, and cousins.