Notices
Results 1 to 5 of 5
Like Tree1Likes
  • 1 Post By Strange

Thread: Dna

  1. #1 Dna 
    Forum Freshman
    Join Date
    Jun 2012
    Posts
    59
    When the police use DNA is there any chance 2 or even 3 people have the same DNA?


    Reply With Quote  
     

  2.  
     

  3. #2  
    Brassica oleracea Strange's Avatar
    Join Date
    Oct 2011
    Location
    喫茶店
    Posts
    16,522
    Yes there is. They choose particular sections of the DNA which are known to be highly variable to make the probability extremely low (1 in several million or whatever). Or at least they are supposed to. I think there have been cases where DNA evidence has been thrown out because it didn't give a high enough probability of identifying a person.

    But note that identical twins (or triplets) will have the same DNA (a popular plot device in things like CSI).


    TimeLord likes this.
    Without wishing to overstate my case, everything in the observable universe definitely has its origins in Northamptonshire -- Alan Moore
    Reply With Quote  
     

  4. #3  
    Forum Freshman
    Join Date
    Jun 2012
    Posts
    59
    Thanks I thought they could but I was told they couldn't.
    Reply With Quote  
     

  5. #4  
    Forum Junior JoshuaL's Avatar
    Join Date
    Mar 2011
    Location
    Seattle
    Posts
    268
    Quote Originally Posted by TimeLord View Post
    Thanks I thought they could but I was told they couldn't.
    It is likely that as the technology becomes cheaper we will reach a point where we can identify to an individual with extreme accuracy. That would be very time consuming and cost prohibitive at the moment, but there is no reason we can't get there eventually. On a related note, folks who have undergone stem cell transplantation will have mixed DNA--their own, plus the DNA of their donor (assuming a successful graft). This is called "chimerism", and is also a common plot device in procedural dramas.
    Reply With Quote  
     

  6. #5  
    New Member
    Join Date
    Jan 2013
    Posts
    2
    It's highly unlikely, but can happen. When being described in court, some lawyers like to word it in a way that it sounds impossible (1 in like 300 billion chance that a DNA profile matches to two people, since it's above the population of the Earth, that must mean that only one person has that profile). It may sound impossible, but there is a random chance that it can still happen, even if they aren't identical twins. (On a side note, through my own DNA testing, I just found out my sister and I are identical twins)
    Reply With Quote  
     

Similar Threads

  1. "Junk" DNA or Useful DNA?!?
    By forensicIRL2011 in forum Biology
    Replies: 1
    Last Post: March 5th, 2011, 12:40 PM
  2. DNA
    By verzen in forum Biology
    Replies: 25
    Last Post: January 2nd, 2009, 07:20 AM
  3. DNA
    By thyristor in forum Biology
    Replies: 1
    Last Post: April 8th, 2008, 03:31 PM
  4. Dna polimerase types of DNA replication
    By SkyDreamer in forum Biology
    Replies: 2
    Last Post: March 2nd, 2008, 11:59 AM
  5. DNA
    By zeus in forum Biology
    Replies: 18
    Last Post: April 12th, 2007, 11:29 AM
Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •