Genetic Diversity … Young or Older

At www.geneticarchaeology.com/research/Archaeological_genetics_Its_not_all_… … presents us with some evidence genetics is not all it is cracked up to be. Okay, genetic differences crop up but how far back do they go. As the blog author notes, the new study, published by BioMedCentral's open access journal Investigative Genetics could be interpreted as old or new – take your pick of the apples. The article authors go for the new, claiming that genetic diversity in the human population of the Netherlands reflects known migrations over the last 2000 years. However, the same results could be explained by older Palaeolithic and Neolithic population movements, it is conceded – but the older pattern is disputed as they favour the new. It reminds me of genetic movements mooted in Clive Finlayson's The Humans Whe Went Extinct (Oxford University Press: 2009) where genetic evidence is said to reflect farmers moving out of the Fertile Crescent, across Anatolia and into Europe, a known archaeological movement of people. Likewise, it is also thought that Ice Age Palaeolithic people migrated northwards into Scandinavia and NW Russia as there are similar genetic links between the two, alleged to be a migration of people following the reindeer herds as they moved northwards with the melting ice sheet. Once again, there was also a similar movement of people in the Palaeolithic, from NW Russia and northern Asia into Europe around 50,000 years ago (in the opposite direction but a movement that would presumably have left behind a genetic marker especially as we are not entirely sure that people really did follow the reindeer herds out of Iberia). Likewise, the main Palaeolithic movement into Europe was from western Asia (including Anatolia and the Fertile Crescent). What is being picked up here – the recent movements of people or the older movements. We may also note Neanderthals were also common to Europe and western Asia – just how old are these genetic signals?