troublesome sentence paleolithic europeans seem to have been a homogenous population possibly due to a population bottleneck or near extinction event on the iberian peninsula where a small human population is thought to have survived the glaciation and then expanded into europe during the mesolithic period this is false i cannot recall any study which asserts confidently that palaeolithic europe was genetically homogeneous if there is one it would require in line citation i think whoever wrote the sentence has confused themselves the studies have rather shown that mesolithic europe became more homogenepus because of population bottlenecking with subsequent expansion the bottlenecking did not cause a homogeneous palaeolithic population becuase the events occurred subsequently