The exact number of early human species is debated, but most scientists accept at least 21 human species. The following is a list of some of the human species recognized by most scientists:

• Ardipithecus kadabba
• Ardipithecus ramidus
• Australopithecus afarensis
• Australopithecus africanus
• Australopithecus anamensis
• Homo habilis
• Homo rudolfensis
• Homo erectus
• Homo antecessor
• Homo heidelbergensis
• Homo naledi
• Homo floresiensis
• Homo neanderthalensis
• Homo luzonensis
• Homo sapiens

It is important to note that the story of human evolution is not one of neat, linear progression with a concrete beginning and end. Instead, it is a tale of a family tree whose complex and bushy branches stretch over many millennia and continents. Adaptation, survival, and extinction provide the dynamic backdrop to this story.