Gene Tree (image) University of Utah Share Print E-Mail Caption These population trees with embedded gene trees show how mutations can generate nucleotide site patterns. The four branch tips of each gene tree represent genetic samples from four populations: modern Africans, modern Eurasians, Neanderthals, and Denisovans. In the left tree, the mutation (shown in blue) is shared by the Eurasian, Neanderthal and Denisovan genomes. In the right tree, the mutation (shown in red) is shared by the Eurasian and Neanderthal genomes. Credit Alan Rogers, University of Utah Usage Restrictions Non commercial reuse with attribution Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.