Download The Quest for Ancient DNA

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/