It works the other way around though, just having some random pictures put together doesn't prove anything.. You need to provide evidence that for instance a european skull (does not) differ as much from another european skull compared to the difference of a european skull to one of other origin, like asian or african.
These pictures have not done that because they are just random skulls of random people, the comparison is flawed because you have not shown that european people all have the same skulls with the same features.
I know there have been studies on skulls of different races.. Its called Craniometry, so you'd do best if you start looking in that direction.
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