Great Chain of Being vs Darwin

In the pre-1859 thinking that lay behind the concept of The Great Chain of Being , all species of Life were born on the same day (all had a common birthday) but all were subject to different individual creations (so had different 'parents' , in a metaphorical sense).

 In 1859, Darwin neatly reversed this : now all species of Life had one common parent (some slimy little bacteria) but all the species had wildly different birthdays, as Life branched out over time from that early single bacteria's beginnings.

Cue the scientific 'justification' for Aktion T4 and the Holocaust.