How can a man DNA identify his family tree through his blood DNA or Semen DNA ?

[password]

I am new on this forum and i have a science question that i am researching, please provide answer.

 

 

How can a man DNA identify his family tree through his blood DNA or Semen DNA ?

 

If wet or dry semen is provided for test, can the test of a man DNA be identified to a family tree ?

 

Thanks for answering me both the questions.

[Endy0816]

I think cheek swabs are normally used.

 

It can be used to identify relations. Generally used to provide more general info though.

 

Most family trees are based on presumed parentage. How are you hoping to use it exactly?

Edited January 29, 2017 by Endy0816

[Country Boy]

With samples of the man's DNA and the DNA of supposed parents, grandparents, etc. you can determine whether or not they share enough DNA to actually be "parents, grandparents, etc.". But the man's DNA alone will not "identify" his family tree. Perhaps you are referring to those "services" that use your DNA to tell you "where you are from"? Those do not determine your family tree- they simply identify parts of the world where that DNA is very common.