DNA 3 - MT2 Flashcards
What has Thomas Jefferson been long time suspected for?
Having fathered one or more children by Sally Hemings
Who was Sally Hemings?
She was a 14 year old slaved owned by Thomas Jefferson
How many living patrilineal descendants of Thomas Jefferson are there?
5
- TJ himself had no male children from his marriages who survived to adulthood
How many living patrilineal descendent of Sally Hemings are there?
1
- Eston Hemings Jefferson (the son)
What did the DNA results saw about the Y chromosome patterns?
That Eston Hemings Jefferson living descendant and the living descendant of Thomas Jeffersons paternal uncle were a match
How was a victim from Jack the Ripper linked to long time suspect Aaron Kosminski?
By DNA evidence
- blood from Catherine Addowe’s shawl
- the shawl was found near Catherine and the blood matched Aaron
- DNA pattern found on it was common so they couldnt use it
How is mitochondria DNA inherited?
Maternally inherited
Genetic drift
Variation in the relative frequency of different genotypes in a small population, owing to the chance disappearance of particular genes as individuals die or does not reproduce
What happens if population numbers are small?
The you get larger variations (sampling errors)
When is there a nesting effect among the variants?
When one group gives rise to another group
- could use the variants tot race back to where it originated
What population are more genetically diverse?
African populations
African Model
Proposes a single origin of homo-sapiens in the taxonomic sense
- would expect less variation in migrating populations
What are the 2 models?
- Out of Africa
2. Multiregional
Founder effect
The reduced genetic diversity that results when a population is descended from a small number of colonizing ancestors
- this is a special case of genetic drift
How can DNA markers help determine ancestry?
Because specific markers are found in specific human groups, analysis of you DAN can tell you some things about your ancestry
What can markers not tell you?
No biological marker for specific places
What are the 2 most frequently used markers?
- Y chromosome
2. Mitochondrial genome
Mitochondrial eve
When the original analysis of the DNA in the mitochondria of modern humans was carried out, the results suggested that all modern humans share the DNA of a single individual female who lived a few hundred thousands years ago
What can help with diagnosis and treatment?
Studying diseases with a genetic component at the level of a gene
What was considered the holy grail?
Getting information from genes about diseases
Huntington diseases
A rare disease that deteriorates neurons that affect adults in their 40s
- comes from a dominant allele
What does it mean when you have less than 35 CAG repeats?
Then you are fine and shouldnt get Huntington disease
What does it mean when you have more than 35 CAG repeats?
That you are highly likely to get the disease
Herceptin treatment story
Cancer cells assayed fro HER2-genetic copy number by it situ hybridization
- encourages cells to divide
- the drug binds to this and decreases the cells to divid
- the drug is hard on patients so dont give it if you dont have to
DNA barcode project
An attempt to derive a set of unique DNA markers for wild animals and plant species
- such markers can be used to fight the illegal trade in endangered organisms
What were the first domesticated species?
Dogs
