I'm pretty late to the party but here's my input-
forget sexual selection or evolving to become white due to attraction, the reason why white people are white is due to diet mainly due to the monster food they consume, wheat.
Early farmers chose voluntarily to switch from a 'hunter gatherer' society to that of agriculture, that requires specialist resources and training to be able to cultivate and grow crops so much so that most of the world still consumes a newer skewed 'hunter gatherer' diet of meat and carbs. Early europeans on the other hand deliberately ditched meat and focuses soley on agricultural products mainly wheat products like wheat, eating meat at most once a week which is almost unheard of now in the modern world. Ah, you may ask eating wheat alone cant make you white can it? Here's where it gets complicated.
Wheat contains the substance WGA also known as wheat germ agluttin. this is probably one of the most destructive substances that the human body can come across. Originally evolved to stop insects eating wheat, WGA is a tough rubber like compound sharing a similar composition to rubber or latex. its composition means it is not broken down by the body even when boiling and rapidly causes chaos to the body. within a few minutes WGA is present in every single cell in the body (yes every. single. one.) and directly disrupts vitamin d synthesis and absorption. because it cannot be broken by any biological enzymes it stays their and the body is rendered totally unable to make use of vitamin d for about 3 hours before wga is finally removed. if you consume large amounts of bread particularly unrefined brown/wholemeal bread where wga is in the highest concentration as would be the only food available to early europeans you have a permanent presence of WGA perpetually fucking up the bodies vitamin d synthesis and extraction and severely deplenishing vitamin d available for bodily processes. because vitamin d is so important to the human body and is used every where from blood production bone formation brain development, brain maintenance, metabolic equilibrium, heart function liver function and prevention of cellular atrophy, a lack of vitamin d to the WGA infused humans would quickly kill them off. the only humans who could survive where the ones who could get vitamin d in a constant stream and more consistently, and that would be paler people whose more sun permeable skin which leads to vitamin d production would have more vitamin d available and give WGA a longer time to completely disrupt the bodys vitamin d supply, allowing the body to use the excess vitamin d where it is actually needed- for development, with the extra vitamin d produced effectively neutralising any WGA present which only pale skin would allow. any non white people eating a european diet would either adapt or quickly die off and only white people would be left which you see.
EXTRA
WGA also severely cripples the immune system deactivating natural killer t cells and causes hyper inflammation in the small intestine. repeated exposure over thousands of years to wheat and ingesting WGA has lead modern europeans to be more susceptible than the rest of the population to a variety of bowel disorders (such as gluten intolerance, celiac disease and many others) and immunological disorders like multiple sclerosis, psoriasis, alzheimers, inflammatory bowel disease dementia and many more. why did i mention dementia? WGA also directly damages the cells genetic code making people more susceptible to mental disorders, dementia, schizophrenia and many more. basically WGA is a nuclear bomb that certain groups of people constantly endured over thousands of years, making them white. while its noted that WGA negatively effected european people, every humans cellular biology makes them equally susceptible to WGA and its adverse effects, with no immunological condition or biological disposition required for it to affect you.
Explains why white people are fucking insane, and the (((jews))) with their favourite food being bagels, are the most insane.