As many people noted, we either outcompeted, killed off, or interbred with other members of the homo genus. Even if we hadn’t, Homo sapiens travel all I’ve the world every day. We have permanent settlements in all but the harshest environments. If other members of the homo genus had survived, we would have encountered them, and either fought or bred with them. Every other multi-species genus can’t travel the world at the merest whim. Fish, marine mammals, birds, and even butterflies are capable of making tremendous journeys all over the world, but they largely have to follow food sources and/or migratory patterns, which could prevent them from encountering closely-related animals. There is very little choice in where they go.
chaddict t1_jebi5fv wrote
Reply to Why are there multiple species of various life forms, but humans only have one? Are there other complex single-species organisms? by CyberOGa3
As many people noted, we either outcompeted, killed off, or interbred with other members of the homo genus. Even if we hadn’t, Homo sapiens travel all I’ve the world every day. We have permanent settlements in all but the harshest environments. If other members of the homo genus had survived, we would have encountered them, and either fought or bred with them. Every other multi-species genus can’t travel the world at the merest whim. Fish, marine mammals, birds, and even butterflies are capable of making tremendous journeys all over the world, but they largely have to follow food sources and/or migratory patterns, which could prevent them from encountering closely-related animals. There is very little choice in where they go.