According to actually scientific research (in contrast to revisionist feminist and regressive liberal propaganda), the half-life of DNA is 526 years (see The half-life of DNA in bone: measuring decay kinetics in 158 dated fossils from The National Center for Biotechnology Information advances science and health.)
This means that, after 526 years, half of the nucleotide bonds that hold DNA together are broken, and another half from remaining DNA bonds keep getting broken every 526 years.
In other words, in the case of "Cheddar Man", whose bones are supposed to be dated 10,000 years back, about 90% of the nucleotide bonds that hold his DNA together would have been broken, leaving only 10% intact, and certainly not enough to gather any reliable information without wild extrapolations.
It is therefore no surprise that the alleged ancestor of the British was claimed to be black. The real surprise is that he was claimed to be purple, and pink, and blue, and other lovely colors which would have greatly complimented a gay pride float, and thus been very inclusive as Kuntistan (formerly the United Kingdom) is brainwashed to be.