0:00 so the probability that a full sip that
0:03 is your brother or sister they're not
0:05 identical twins has a given genotype for
0:09 a homozygote is one plus the allele
0:11 frequency of whatever that allele is
0:13 squared over four and then the
0:17 heterozygotes are what you see there for
0:19 two alleles so that's how the paternity
0:24 calculations work you know it's give or
0:27 take it's around a quarter for locus and
0:30 k is the number of low size so the
0:32 probability that two full siblings have
0:35 a given genotype that's two Leal's
0:39 is 1/4 to the K K being the number of
0:43 low site because the probability that
0:46 they have one allele is what from one
0:49 parent right get one from one chromosome
0:55 or the other right probability that they
0:57 have an allele from the other parent is
0:59 yeah what's probability that they have
1:01 both 1/2 times 1/2 so for a genotype
1:06 that's two alleles 1/4 to the K okay
1:12 being the number of low site
1:14 you can see that when you get to 13 the
1:18 probability that two full sibs are gonna
1:20 have same genotype across 13 lows I know
1:26 you know you're assuming that parents
1:29 are heterozygous too right
1:31 so parents are homozygous then the
1:34 probability of getting it is not it's 1
1:38 but on average you could even multiply
1:42 that by 0.8 because 80% heterozygosity
1:44 right still gonna be pretty small one in
1:50 that's like almost 80 million you follow
1:54 me so these systems can even
1:58 discriminate amongst first-degree
2:01 relatives pretty well you have enough
2:04 low side maybe one low because you may
2:05 not be able to just depends on the
2:07 genotypes but over 13 you're getting
2:10 enough genetic information to
2:11 discriminate between them
