would a dna test show a difference if two brothers that are years apart but have the same mother and father?

5 Comments

1. Dan S says:

   October 27, 2009 at 1:10 am

   A DNA test can determine the parents of a person, but not their age. Eventually we could determine the age of a person by the number of replications possible for a specific strain, but even then it would only be an approximate value.

   The only people who have the same DNA are identical twins; in this case the single fertilized egg splits and forms two fetuses so they share the exact same DNA. In every other case the DNA varies with the person, but family members will have some factors in common.
   .
2. van v says:

   October 27, 2009 at 1:10 am

   no DNA is different for everyone even twins don’t have same DNA they do have a lot of it in common though
3. Druid says:

   October 27, 2009 at 1:10 am

   >Yes…all individuals have unique DNA…(except identical twins).<
4. Yash D says:

   October 27, 2009 at 1:10 am

   If what you are trying to say is that whether it can be found that they are children of the same parents or even if they share a common parent then yes its true, the DNA of no two people can be absolutely the same, those would be clones then. however siblings, parents, relations share common strands of DNA. and it has been possible with the help of tests to prove these. age makes makes no difference, in fact generations later persons can still find out if they are descendants of who they think they are provided DNA samples are available. hair / blood / saliva / bone material is commonly used but often these samples are damaged (in case of very old ones) – the DNA / RNA on them is so far gone that detailed tests become difficult and in some cases impossible.
5. Debbie V says:

   October 27, 2009 at 1:10 am

   Everyone has their own personal DNA (except twins). But it should be similar enough that they can determine if the two children’s DNAs came from the same father & mother.

   TX Mom