Also, I like the bit in the far-left corner of that graph which alludes to Possible Additional Hominim. Now, consider dwarfism of elephants on island/s that couldn't support large herbivores, as in Siberia, for example. What happens? They adapt and get smaller etc. Same thing for humans. On the island of Flores, I met a priest, RC, who was also an archaeologist etc. and he showed me the finds of Homo Florensis, sometimes referred to as Hobbits : ). To my mind this was a strand of Homo Erectus getting adapted to the environment until Homo sapiens sapiens arrived, later on.

https://en.wikipedia.org/wiki/Homo_floresiensis