U.S. flag
      An official website of the United States government, Department of Justice.
        Here's how you know
      Here's how you know**Official websites use .gov**
            
            A **.gov** website belongs to an official government organization in the United States.
      **Secure .gov websites use HTTPS**
            
            A **lock** (
            A locked padlock
            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites. Menu

      
        close

            
            
                                              About NIJ
        
                    
  
          About NIJ
      
    
          The NIJ Director
          How NIJ Is Organized
          Mission and Guiding Principles
          Strategic Framework
          Research and Development Process
          Assessments of NIJ
          Annual Reports & Reports to Congress
          Staff Directory
          Funding & Awards
        
                    
  
          Funding & Awards
      
    
          Current Funding
          Forthcoming Funding
          Expired Funding
          Awards: Listing of Funded Projects
          Guidance for Applicants and Awardees
          Fellowship & Student Programs
          Travel Scholarships
          NIJ Challenge Program
          Library & Multimedia
        
                    
  
          Library & Multimedia
      
    
          NIJ Journal
          Podcasts
          Publications Listing
          Multimedia Listing
          Rated Practices on CrimeSolutions
          Rated Programs on CrimeSolutions
          Software & Databases
          Datasets
          Patents
          Topics
        
                    
  
          Topics
      
    
          Article Listing
          Corrections
          Courts
          Crime Prevention
          Crimes
          Drugs and Crime
          Equipment and Technology
          Forensic Sciences
          Youth Justice
          Justice System Reform
          Law Enforcement
          Tribal Crime and Justice
          Victims of Crime
          Events
        
                    
  
          Events
      
    
          NIJ 2024 Research Conference
          Scheduled Events
          On-Demand Events
          Research Meetings & Workshops
          NIJ-Hosted Online Training

                            
                                About
          Contact Us
          Subscribe
          Topics A-Z
                  Share
FacebookXLinkedInRedditPinterestEmail Home
 Lecture on Paternity Calculations

January 9, 2019
Review the YouTube Terms of Service and the Google Privacy Policy
See reuse policy
  
  
          Transcript
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
    
  
Disclaimer:
              Opinions or points of view expressed in these recordings represent those of the speakers and do not necessarily represent the official position or policies of the U.S. Department of Justice. Any commercial products and manufacturers discussed in these recordings are presented for informational purposes only and do not constitute product approval or endorsement by the U.S. Department of Justice.
  
Date Published: January 9, 2019
    
          Side navigation
  

        

  
  
              NIJ Journal
    
      
            
            
            
      Podcasts
    
      
            
            
            
      Publications Listing
    
      
            
            
            
      Multimedia Listing
    
      
            
            
            
      Rated Practices on CrimeSolutions
    
      
            
            
            
      Rated Programs on CrimeSolutions
    
      
            
            
            
      Software & Databases
    
      
            
            
            
      Datasets
    
      
            
            
            
      Patents
 Top

      National Institute of Justice

        
        
                        About NIJ
                    About NIJ
      
    
                  How NIJ Is Organized
      
    
                  NIJ Director
      
    
                  Research Disclaimer
      
    
                  Funding & Awards
                    Funding & Awards Home
      
    
                  Awards Listing
      
    
                  Current Funding
      
    
                  Guidance for Applicants and Awardees
      
    
                  Resources
                    Events
      
    
                  Podcasts
      
    
                  Publications
      
    
                  Topics
      
    
                  Multimedia
      
    
                  Reuse Policy
      
    
                  Contacts
                    Contact NIJ
      
    
                  Staff Directory
      
    
                  Submit a FOIA Request
      
    
                  File a Civil Rights ComplaintFacebook
          
                      X
          
                      YouTube
  

      810 7th St. NW, Washington, D.C. 20531
      
              Secondary Footer link menu
            Accessibility
              Plain Language
              Privacy Policy
              Legal Policies and Disclaimer
              No FEAR Act
              Freedom of Information Act
              USA.gov
              Justice.gov