Peg writes:However, at some point down the track, the evolutionists began to realise that the 'origin' of life itself is a different topic to the evolution that they were studying. They have since separated the two subjects into
1. Evolution - 'the changes we see in populations over time'
&
2. Abiogenesis - 'the origin of the first living things'
As far as I know, Darwin called his book "The Origin of Species". He did not call it "The Origin of Life." So it seems that evolution was already understood to be changes in populations over time. The "separation" you describe appears to be mistaken.