Genomic data obtained, that represents 1,34% and 0,53% of the total Genome of both individuals, show that they are not directly related to modern populations at the Iberian Peninsula. The Mesolithic Iberians are closer to current Northern Europeans, that may have assimilated part of genetic legacy of those hunther-gatherers.

Researchers have also recovered a complete mitochondrial genome from one of the individuals, and so we now know that along Mesolithic the European polulations were genetically very uniform.

The oldest human prehistoric genomes

To date, we only had access to one European Neolithic prehistoric genome, Ötzi; Also known as "IceMan". His mummy belong to a man 5.300 years-old and was discovered in the Alps of Tirol.

La Braña-Arintero is potentially a unique archaeological site that has allowed the preservation of DNA previous to the Neolithic. As Lalueza-Fox explains, this is only a preliminary result, as the team has the intention to retrieve the complete genome from those individuals and compare it to that of modern Europeans. 

Mesolithic is a period between Paleolithic and Neolithic, the latter characterised by the arrival of agriculture and farmers from the Middle East.

The arrival of Neolithic represented the substitution of populations and a series of genetic changes in genes associated to new infectious illnesses and in metabolic genes associated to changes in diet.  The information that these genomes may bring it is crucial for understand the past of European populations.  

Reference work:

Sanchez-Quinto et al. 2012. Genomic Affinities of Two 7,000-Year-Old Iberian Hunter-Gatherers, Current Biology. Ahead of print; http://dx.doi.org/10.1016/j.cub.2012.06.005