The ancestors of all modern humans split off from a mystery population 1.5 million years ago and then reconnected with them 300,000 years ago, a new genetic model suggests. The unknown population contributed 20% of our DNA and may have boosted humans' brain function...In a study published Tuesday (March 18) in the journal Nature Genetics, researchers presented a new method of modeling genomic data, called "cobraa," that has allowed them to trace the evolution of modern humans (Homo sapiens).By applying their new method to modern human DNA data published in the 1000 Genomes Project and the Human Genome Diversity Project,...