0:00

what happens when you get an allele at a

0:04

locus for one of your markers that has

0:07

an allele frequency of zero if you're

0:11

using pop stands what does it do

0:15

right how do you know its use that in

0:18

pop stats

0:19

oh how do you know then they put the

0:30

number in for you correct there's a

0:34

little M that they print out beside the

0:38

allele you'll see an M that means

0:44

minimum allele frequency and there are

0:48

different ways of calculating it I did a

0:51

bunch of research on this when we were

0:53

trying to get our SOP written for how to

0:56

do this in Denver so I did a little bit

0:59

of research and I found that there's

1:02

actually three three ways of doing it

1:04

that are published first is using two

1:08

pieces of information the Alpha level

1:10

which is your level of confidence right

1:12

95 percent or 5 percent so alpha would

1:15

be 5% if you want to be 99 or 95%

1:18

confident 1% if you wanted to be 99

1:21

percent confident and is the number of

1:24

people in your database okay you know

1:28

that for each group that sometimes

1:30

varies that varies between the groups

1:33

right different number of people so the

1:35

first one from 1992 takes into effect

1:39

accounts for the level of confidence and

1:42

the number of people in the database

1:43

that's the top formula there the next

1:46

one that came out International Journal

1:48

legal medicine in 96 it has a little bit

1:50

more information it uses the Alpha level

1:53

it uses the number of people in the

1:56

database but it also uses C which is the

2:00

number of common alleles at the locus I

2:03

chose that to use that in my when we

2:08

before we were using pop stats I chose

2:10

to use that form of

2:13

the minimum allele frequency because it

2:15

had the most information accounted for

2:18

right and then in NRC two they recommend

2:24

five over 2n okay so you guys are

2:28

critical thinkers what do you think

2:32

between these three what would you do

2:35

and how would you decide well the reason

2:42

I decided on the middle one when I did

2:43

was because it was published the other

2:46

two are as well one is in NRC 96 the

2:49

other ones in a 1992 book by weird I

2:51

chose the middle one because it had more

2:54

information it accounted for more in the

2:57

database right not just the number of

2:59

people but the number of common alleles

3:01

well as it turns out if you look at

3:07

different n sizes numbers of people in

3:10

the database and you look at the NRC to

3:13

5 over 2n you get about at the very top

3:19

0.025 right 150 people vote point oh one

3:26

seven 200 people about 0.01 most of our

3:32

databases that we're using are on the

3:33

order of about 200 people right so you

3:37

can see that 5 over 2 n gives whether

3:40

you have 200 people about 0.01 or 100

3:46

look at the difference between the 3

3:49

methods now over the same number okay

3:53

around 200 people

3:55

Weir's gives point zero zero seven five

3:59

well if you round that up what do you

4:01

get

4:05

what's the point 0 0 75 rounded up 0.01

4:10

right to the next decimal place

4:12

what about Bedok Lee's method that's the

4:16

International Journal legal medicine

4:18

1996 0.01

4:22

what about NRC to 5 over 2 N 1 ok that's

4:28

with the top with a minimum allele

4:31

frequency where alpha is 0.05 and you

4:33

have 8 alleles what about if you have

4:38

double the number of alleles you have 16

4:41

alleles now well what happens for about

4:44

200 people when you get think the

4:53

numbers are slightly different but the

4:54

practical significance isn't right get

4:57

about point or what