So somehow Men with Y Haplogroups O, N , and P(Q) all evolved into the same Mongoloid race independently and somehow P(R) did not? Impossible.
You are making this more simple than it really is. We don't really know what Caucasoid and Mongoloid are yet, they are probably multiple things(we know all modern west Eurasians have none west Eurasian ancestry from 'basal Eurasians"). The common ancestor of NO and P probably existed before the west and east Eurasian split. We know that through ancient DNA that 45,000 years ago in western Siberia there were people who were equally related to east and west Eurasians. So even if the common ancestor of NO and P gave rise to east Asians, one branch(P) could have mixed with people who did not give rise to east Asians and the carriers of P could have become western autosomally, like early carries of mtDNA U and Y DNA IJ.
24,000 years old Siberian MA-1 had Y DNA R, mtDNA U, and was a pure west Eurasian with no evidence at all of east Asian ancestry. 17,000YBP Siberian AG2 had Y DNA P, mtDNA R*, was probably a pure west Eurasians and had no signs of east Asian ancestry. Siberians and Native Americans have high amounts of Y DNA Q but they also have some west Eurasian ancestry(around 20% for many Siberians and 40% for native Americans), specifically from MA-1's people, while there are plenty of west Eurasian people like Polish and Irish with high amounts of Y DNA P but no signs of east Asian ancestry. Y DNA Q probably did not originate in Siberia or a people with mainly east Asian ancestry, it is a terrible assumption that it's a "mongoloid" haplogroup.
The most reasonable scenario is that the R1 subclades (or proto R1) originated as Mongoloid and bred with Caucasoid women in Central Asia, Near East, and Europe as they migrated there diluting their own original genetic makeup until they became a hyrbrid majority Caucasoid. The pure Caucasoid form has a Dolichocephalic(Long) headshape and the pure Mongoloid has a brachycephalic(Wide) headshape, in central Europe we see a Mesocephalic headshape(Mixture between the two) and Dolicephalic prevaling in the more remote regions (North Sea/Scandinavia), this fits the introduction and dilution of a Bracephalic genepool from East Asia. Neolithic farmers and indigenous europeans could not explain the Mesocephalic headshape in central europe as both groups would have been homogenous Caucasoid/Dolicephalic.
I don't know enough about the subject to say anything but I do know there is no evidence on Y DNA, mtDNA, or autosomal DNA of widepsread east Asian ancestry in Europe.
The interesting part of the puzzle now I think is pigmentation, we know that the indigenous hunter gatherers were Dark Skinned but had the blue eye trait, Neolithic Farmers had the Light Skin Allele but can't explain red/blonde hair.
Seems like Modern Europeans are the result of mixing :
Mongoloid R1a/b carrying the MC1R mutation for red hair and possibly blonde hair with Light Skinned Caucasoid farmers in the Near East, then further mixing of these people with more Dark Skinned Caucasoid HGs in Europe. This fits the theory of light skin evolving in tandem with origin of farming. Somewhere in there we have the first Neolithic farmers spreading their light skin genes into the dark skinned HGs of Europe with the LBK, but this probably didn't have the same impact the Indo-Europeans did on the genepool who probably brought much more light skin and mixed much more.
To label them with haplogroups:
R1a/R1b mix with Neadertals in Siberia picking up traits for red/blonde hair (MC1R) which exist unexpressed.
R1a/R1b men mix with mtDNA H women in the Near east picking up the light skin gene (SLC24A5).[/QUOTE]
It is a big stretch to have such a strong opinion on this pigmentation connection when you're not an educated expert. How do you explain Finnish being the most blonde people in Europe and having low amounts of Y DNA R1? Y DNA R1a and R1b became widespread and popular in Europe in the last 5,000 years, and you're forgetting about west Asians who also have a high amount(plus R1b probably originated in west Asia some 20,000 years ago).