A species is the primary unit of biological classification or taxonomy. Species members share a basic genetic similarity and can interbreed and produce fertile offspring.

“Birds” describes the Genus - Robins and Magpies are part of the same Genus, but there are different species of Robins (e.g. Red breasted Robin etc etc).

And speciation occurs for many different reasons, but it basically boils down to adapting to their environment to such an extent that they can no longer interbreed. And humans have never reached that extent, ipsofacto there is only one “species” of human (although we have “races” which define our adaptations to different environments - like the Chinese generally cannot tolerate alcohol like Europeans because they have not developed tolerance against it).

I believe this is right-ish, although I did learn this from you-know-who, so who knows, it could be complete and utter BS!

Ah yeh, I’ll wikipedia it, more reliable than you-know-who anyway…actually I think that’s where she gets her material from…