If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.
half of your DNA comes from your father. However, which part of the DNA your father gives you is random. May be most of the DNA your father gives you comes from your paternal grandfather, but may be most of it comes from your paternal grandmother. Each chromosome (except the Y chromosome) is a mixture of all your previous lineages. Theoretically, you could have none of the DNA of your paternal g-g-g-grandfather, or you could have a lot of it.
The peculiarity of mtDNA and of the Y chromosome is that they are passed on as a whole without mixing. So the mtdna is exactly the same as your female ancestor hundreds of generations ago (plus of course the intervening mutations), and you can trace a lineage. In other words, you are 100% sure that the mtdna is exactly what you got through the female line, and the Y is exactly what one got down the generations through the male line. You cannot do that with the other chromosomes.
However, you can trace individual genes across generations. Indeed, that's what happens with most genetic medical tests. If there is a disease anywhere in the family (father/mother/etc.) one can test oneself and see whether one has the particular gene.
Comment