Lec 15 (ancient DNA) Flashcards
What main things are we interested in in population genetics?
- SNP
- how many people in a pop have that specific SNP
- allele frequency
- frequency change over time = changes are due to the environment
What does LP stand for
lactase persistence
What are the key definitions used in population genetics
3
- ancient DNA
- Gene frequency
- Allele frequency
Define population genetics
it is the study of changes in the genetic composition of a population that occur over time and under evolutionary pressures
population genetics extended the principles of ____ and ___
Gregor Mendel and Charles Darwin
What does LNP stand for? aka __
Lactase non-persistence
lactose intolerance
Population genetics studies the transmission of ___
Population genetics studies the transmission of genetic variation in populations
Hypoxia gene in south America provide an adaptation to survive ____
Hypoxia gene in south America provide an adaptation to survive in high altitudes
Define population
A group of interbreeding individuals of the same species that inhabit the same space at the same time and share a gene pool
Define gene pool
Sum of the alleles carries by all members of a population
square = male/female
male
What is a SNP?
a Single nucleotide polymorphism
A single nucleotide locus with 2 naturally existing alleles defined by a single base pair substitution
SNPs make up around __% of all human genetic variation
90%
__ are the most frequenct genetic variant
SNPs
What must occur in at least 1% of the population to be considered a ___
SNP
In the paper published in 2014, a SNP had been identified. What was this and where?
SNP was a change from a C (cytosine) to a T Thymine) at position -13910.
What does it mean to have an autosomal dominant trait?
You only need one copy of the trait to display it
Briefly describe the genetics of Lactase persistence
- autosomal dominant trait
- enabling life-long digestion of lactose (milk sugar)
- Ezy = lactase-phlorizin hydrolase (LPH)
- lactase persists into adult life in some, but not all. people
- common genetic trait in many European. African and Middle Eastern Populations
What does LPH stand for and what is it?
LPH= lactase-phlorizin hydrolase
the enzyme for lactase persistence
What is a possible reason as to why LP is a common trait in european, African and Middle Eastern Populatoins
The selection may be due to one of the nutrients or water in fresh milk and/or its calorific value
What is the reaction for the breakdown of lactose
Lactose (disaccharide sugar)
Lactose + H2O ==(lactase)==> galactose + glucose
which can then be absorbed by the small intestine
In terms of the breakdown of lactose, what occurs in lactose-intolerant individuals?
Lactose is not broken down into the monosaccharides, therefore, there is a build-up of lactose in the gut which results in bloating, abdominal pain and diarrhoea
LPH ___ lactose into ____ for ___ in the __
LPH hydrolyses into galactose and glucose for absorption in the small intestine
What is the LP in Europe
SNP that changes C to T
