What DNA Says About Our Human Family: Putting Students in the Tree of Human Evolution

Written in each person’s DNA is an unbroken record of our shared ancestry as human beings – where we arose and how we moved and mingled to create the tapestry of cultures we now see around the world. Although people may look rather different on the outside, genetic analysis shows that all humans are closely related. DNA studies confirm that all people alive today are descendants of the first modern humans, who emerged in Africa about 200,000 years ago, and that we interbred with ancient Neanderthals and a mysterious group called the Denisovans. Genes also bear the marks of our mastery over other living things – the domestication of plants and animals.  Learn about the DNA Learning Center’s integrated biochemical and bioinformatics (B&B) workflow that uses students’ own mitochondrial (mt) DNA sequences to discover principles of genetic diversity and human evolution. In class, students use a resin-based method to extract DNA from cheek cells, amplify a hypervariable region of the mt genome by PCR, and confirm results with gel electrophoresis. Student samples are then sent for DNA sequencing, and results are automatically uploaded within 48 hours into Bioservers and DNA Subway – intuitive workflows for sequence alignment and tree building.  Students’ own questions about their relatedness to classmates, individuals from world populations, and ancient hominids then drive their bioinformatics exploration of sequence data – culminating by placing themselves in their own tree of human evolution.