The Quest for Ancient DNA – the Key to our Past DNA Technology and Fossils • Ancient DNA is analyzed from: – Mummies – Organisms preserved in amber – Plant materials found in ancient tombs – Bacteria – Bones What Can Ancient DNA Tell Us? • How organisms of the past are similar or different to organisms today. The Quagga – an extinct zebralike animal Click here to learn how wooly mammoth DNA was analyzed. http://www.devilgraphics.com/pic.php?n=zebra/& b=zebra/ Ancient DNA Pieces Together the History of Man • DNA from the Y chromosome and mtDNA (mitochondrial DNA) occasionally mutate which provides heritable genetic markers. • These markers become part of a population. • The markers help researchers determine migration patterns. • Y chromosome data is used to trace paternal ancestry. • mtDNA is used to trace maternal ancestry. http://www.geocities.com/CapeCan averal/Launchpad/3917/mtDNA.jpg http://www.ucl.ac.uk/tcga/ScienceSpectrapages/pics/14-bradman_fig_1.gif Determining age of Y Chromosome DNA or mtDNA • Scientists believe random mutations occur at a particular rate. • DNA samples from many geographical areas are studied to determine markers and differences in mtDNA or Y chromosome DNA. http://images.google.com/imgres?im gurl=http://files.turbosquid.com How is mtDNA and Y Chromosome Data Collected? • The databases for genetic anthropology are based on samples from people around the world. • Click here to learn more about the Genographic Project and the mtDNA and Y chromosome data that has been collected to determine human migration patterns. • Click here to learn about the HapMap Project. This project is developing a haplotype map of the human genome. • Click here to learn about the Human Genome Diversity Project. The goal of this project is to document genetic similarities and differences among people worldwide. DNA From Other Sources Can Give Clues About Human Migration The Story of Human Migration Also is Told in the DNA of Parasites and Pets. Recent studies of bacteria called Streptococcus mutans, which cause tooth decay, reveal that distinct lineages of the bacteria exist in different geographic regions of the world. The geographical distribution of these lineages reflects the pattern of human migration from the ancestral homeland in Africa. S. mutans is transmitted almost entirely from human mother to child during birth, resulting in the preservation of its lineages over thousands of years. S. mutans is only one of many types of human parasites whose DNA lineages follow the pattern of human migration. How is DNA Analysis Conducted? • Sometimes DNA from fossils has a lot of damage. • However, PCR allows scientists to make many copies DNA from tiny samples. • Various DNA fingerprinting methods are used to analyze DNA patterns. Activities • Click on the link below for a three-part activity on analyzing DNA of human skeletal remains to determine ancestry. To access the activity on the DNAi website, scroll to the bottom of the page and click on the teacher and student pages for “Recovering the Romanovs.” • Recovering the Romanovs • The link on the wiki page for genetic ancestry provides students with information on fossil DNA and using microarrays to analyze migration patterns of early humans. References • • • “DNA discovery may bring long-extinct wooly mammoth back to life.”The Online Newshour Extra with Jim Lehrer. Posted December 9, 2008. http://www.pbs.org/newshour/extra/features/science/july-dec08/mammoth_12-09.html Human Genome Project Information; Genetic anthropology, ancestry, and ancient human migration. http://www.ornl.gov/sci/techresources/Human_Genome/elsi/humanmigration.shtml McClusky, Kevin. “Beyond Jurassic Park: Real Science with Ancient DNA.” Plant Health Progress - Plant Health Reviews - 19 October 2000, Accession DOI:10.1094/PHP-2000-1019-01-RV http://www.apsnet.org/education/feature/ancientdna/