Ice-age Europeans roamed in small bands of fewer than 30, on brink of extinction | Horizon Magazine - European Commission - http://horizon-magazine.eu/article...
"New genomic data suggests that when Europeans emerged from the last ice age they were close to becoming extinct. In some cases, small bands of potentially as few as 20 to 30 people could have been moving over very large areas, over the whole of Europe as a single territory, according to Professor Ron Pinhasi, principal investigator on the EU-funded ADNABIOARC project. This demographic model is based on new evidence that suggests populations were much smaller than is generally thought to be a stable size for healthy reproduction, usually around 500 people. Such small groupings may have led to reduced fitness and even extinctions." - Maitani
Razib Khan's comment on this: http://ff.im/1kUfVu - Maitani