Mysterious 'ghost population' of ancient humans discovered

originally posted by: TheSkunk
How did they all breed if they were not one species?

originally posted by: neoholographic
Good question and this destroys any natural interpretation of evolution.
This could point to an advanced civilization tinkering with the DNA of ancient Hominids. Some people already proposed this with Biological SETI. This could be Alien DNA.

The idea that two species cannot interbreed is false and oversimplified. The is no such criteria in the definition of "species" that says there cannot be breeding between two species, and in fact it happens in nature.

For example, wolves (Canis lupus) and coyotes (Canis latrans) are two distinct species, but they can interbreed and have done so in the wild, resulting in the hybrid and often fertile coywolf. There are also fertile hybrids of big cats.

Wolves, Coyotes, and domestic dogs (which is often considered a distinct species rather than a subspecies) are descended from a common ancestor species, just like H. Sapiens, H. neanderthalensis, and H. denisova (H. denisova is often considered a distinct species) are descended from a common ancestor, H. heildelbergensis.