The short answer is 15 to 20! That’s up to twenty known chapters of human history that have closed forever.
When we refer to “human species” going extinct, we’re discussing members of the genus Homo, all the distinct human species that have disappeared since the emergence of Homo habilis about 2.3 million years ago.
Our planet has been a bustling stage of human evolution, where various human species have walked, foraged, and hunted. To date, numerous human species have gone extinct. These include well-known names like Neanderthals and Homo erectus, as well as less famous but equally intriguing ones like Homo habilis, Homo heidelbergensis, and the recently discovered Homo luzonensis.
Each of these species once roamed different parts of our world, adapting to diverse and changing environments but ultimately not surviving to the present day.