The BBC provides an excellent website with more detail.

GenesConnected, the UKs number one family tree and genealogy site.

The UK Friends Reunited genealogy resource for those around the globe
searching for ancestors and living relatives from a growing database of millions of names. Free family tree-builder and free advice during regular webchats with the sites resident expert genealogist.

The principal discussion site for genetic ancestral research is the Genealogy-DNA website.