L6 population specific variation Flashcards
how does genetic diversity arise in populations
variants intro by muts
lost by genetic drift
what the relationship between diversity and age of population
older pop more genetic diversity
whatcan be revealed from the genetic diversity of a population
age
split from ca
slection pressures within the envuroment
hwo does geogrpahy link to genetic diversity
diversity varies around globe
some phy barriers explan diversity
norm in same area have same ptype
what gene used as a measure of genetic diversity
cd4 - a glyco pr on immune cells
high in afr
low rest of world
name some of the large scale sequencing studies
1000 genomes project
UK10k project
what the findings of the 1000 genomes project
looked at genomes from 26 pops found 88 mil variants afr had most variants show older pops when look at variants that are common in pops but rare globally most div in afr and some peruvian tribees finaland also higher div than rest eu
what are the gentic impacts of colonisation and migration
founder effect
gene flow
what is admixture
the creation of hybrid pop from two ancestral pop
what the general genetic consequence of admixture
introduce new variants
results in incr variation in qtl traits
diff rec alleles decr disease
what other consequence of admixture
new pathogen exposure incr disease
what did genetic studies show about disease outbreaks in mexico in 16th C
salmonella outbreak
strain had been in eu 300 yrs before
spanish conquest - poor sanitary conditions
when did the movement into the american occur
15000ya
what have studies found for genetic evidence of the migration into n.am
studied ams. siberians no eu admix
n.am stem from one group split with asians 23,000
spent 8000 bering strat
entered n.am in a single waave
whta have studies shown about the n.am and s.am split
13,000ya
found ev of aus melanesia in dna of s.am (Raghavan et al., 2015)
what have gentic studies shown about n.am and inuit population
seperate clade whihc are closer to indigenous siberians
what have genetic studies shown about the oceana and s.am populations
found amazonians share more sim with present day aus melanesians (1-2% ancestry)
what is population y
an ancestral population beleived to have contributed to both s.am and oceana
who is pop y thought to be most related to in present day pop and what this evidenve of
aus
than e. asain/siberian
no admixture in bering strait
what problem with conclusions from pop y at the moment
no ancient dna prove
although craniomorphological features of ancestral fossils support
when and where fossil usr1 from
beringia alaska
dated 11.5kya
what has fossil usr1 revelaled/suggested
genome seq shown more related to n.am than any other modern pop
is equal rel to all n n.am and s n.am = usr1split with ancestor of them 20-9kya
(nnam and snam then split at 15kya)
has no pop y ancestry
usr1 decendents in beringia until 11.5
usr1 ancestor split with e.asians 36kya but genome persit until 26kya
also show that after 11.5kya some nna have gene flow from siberian pop
what have studies of south american population revealed about migrations into the countries
varied by countries
what country has the highest n.am genetic sim
n. am
what country has the smallest afr contribution
peru/chile/argentine
where has most the admix in the s.am pops come fromq
eu -iberia = spain
what findings for argentina migration / genetic input
highest number of cluster from italy, models show the migr between 3-9 gen ago. fits wiht the migr that occured in the 19thC-20th C
equal contribution from clusters eu/afr and native american
what findings for ecuador migration / genetic input
the least eu/afr input
what have studies in south american native american shown
no evidence of northern native american in latin derived s.am there are two clusters -central andean -other souther native american = andes geog barrier
what have genetic studies looking at sex xhr in south america shown
gender disparity
more x linked native american allele compared to autosomes
reflects that mainly eu men came over in migr
what is the finnish disease spectrum
different profile of recessive inherited diseases that the finnish pop have compared to surrounding pops
40 rare disease
20% carriers
1:1500 affected
what cause the finnish disease spectrum
geog and language barrier
what different about y chr in finnish pop
diversity lower than other eu pops
give an example of a disease of the finnish disease spectrum
,eckel syndrom auto rec cyctic kidney polydactyl worlwide incidence 0.2 per 1000 finalnd 1.1 per 1000
what examples of environmental adpatation in gentic diversity
inuit and diet (FADS1-3)
lactose tolerence eu and e.afr (MCM6)
light skin eu (MATP/TYR)
altitude andes and himalayans (EGLN1)
describe the fidings of enviromental adaptation in inuit pop
evidene for positive sel in 5 genes
inc FAD1-3
FADS1 and “ encode enzymem that convert PUFA into biol active forms
also strong adpatation signatiures for height and weight
suggest adaptation to survive on diet with no neg impact onw weight
what is the uk10k project
genomic studyin uk
3700 ind eu ancestory
detect rare and low freq variation in uk pop that are in ind with disease/obestiy etc
what has the uk10k project found
576 genes with hom or hetero compound variant predicted to result in loss of pr function
one which osteoporosis variant
what has study in uk10k revealed about osteoporosis variant
id a variant also in icelandic pop
uk110k foudn 3 snps near en1 gene
show high assoc with lunbar coe defect
mouse with the variant lower bone mineral density
