Why are there no indigeonus white people in china?

Question

In some parts of western China Celtic mummies have been found, who genealogically originate from Britain/France - that predate any other settlement in that area...So why are there not any white people in china now?

http://www.independent.co.uk/news/world/asia/a-meeting-of-civilisations-the-mystery-of-chinas-celtic-mummies-413638.html

http://uyghuramerican.org/articles/471/1/A-meeting-of-civilisations-The-mystery-of-Chinas-celtic-mummies/A-meeting-of-civilisations-The-mystery-of-Chi