Station #3 - DNA and Forensic

• Activity #3 - Tracing ancestry with mtDNA (Part 1)
  
  

  - Identifying remains with DNA

  In reproduction, the nuclear DNA of one parent mixes with the nuclear DNA of the other. mtDNA, on the other hand, passes on from mother to offspring unaltered. A baby's genetic information is a mixture of both parents' genetic code. Nuclear chromosomes from a sperm cell (carrier of information from the father) enter the egg (carrier of information from the mother) and combine with the egg's nuclear DNA, producing a mixture of both parents' genetic code. In the combination of genetic information, the mtDNA from the sperm cell, however, is left behind, outside of the egg cell. So the baby contains a mixture of the father and mother's nuclear DNA and an exact copy of the mother's mtDNA, but none of the father's mtDNA. The result is that mtDNA is passed on only along the maternal line. This means that all of the mtDNA in the cells of a person's body are copies of his or her mother's mtDNA, and all of the mother's mtDNA is a copy of her mother's, and so on. No matter how far back you go, mtDNA is always inherited only from the mother. If you went back six generations in your own family tree, you'd see that your nuclear DNA is inherited from 32 men and 32 women. Your mtDNA, on the other hand, would have come from only one of those 32 women.

  Download: Genetic Family Tree work sheet View: All ancestors of the current generation mtDNA ancestor of the current generation mtDNA decendents

  
  

  Activity #4 - Tracing ancestry with mtDNA (Part 2) - Finish on your own to compete for prizes Last Flight of Bomber 31 - The Hunt for mtDNA

  Download: Last Flight of Bomber 31 - Hunt for mtDNA activity sheet

  The Challenge: Your are working as forensic scientists to help solve a long-standing "missing persons" case. An anthropologist has found a few human bones at a site in South Africa. Investigators think they might belong to a Nobel Prize-winning dung beetle biologist who disappeared in Africa. Since the bones have been exposed to severe weather for many years, the only DNA that may be salvageable is mtDNA. Investigators have compiled a pedigree chart that lists all the missing person's relatives. But investigators are having problems identifying his maternal relatives. Which of the people in the Who's Related by mtDNA? pedigree chart carry the great-great grandmother's mtDNA, and of those, which living relatives would be eligible to donate their mtDNA for comparison? The missing person is labeled with a question mark in the pedigree chart. mtDNA can be retrieved from exhumed remains; however, this is a costly process and can be emotionally difficult for families. When possible, it is always best to retrieve mtDNA from a living relative. mtDNA cannot be retrieved from cremated remains.

  
  
  

  Activity #5 - Tracing ancestry with mtDNA (Part 3) - Your own research to compete for prizes Are Neanderthals human ancestors?

  Homo sapiens neanderthalensis were human-like hominids who existed between 32,000 and 100,000 years ago, and are thought to have lived side by side with modern humans for over 10,000 years. Neanderthals Links: Neandertals: A Cyber Perspective The mtDNA Debate Links: 1 | 2 | 3 | 4 | 5

  
  
  
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