I'm not understanding why the old Y DNA and mt DNA results aren't or are (respectively) linked the way they are to our trees. For example, an mtDNA test my mom did is linked to my mom, my grandmother on mom's side, my great grandmother on mom's side, etc). I understand this.

However, the Y DNA comes from my dad and his dad, and his dad and so on. So why aren't these Y DNA results attached to my tree?

Thanks
Stephen Moore