A decedent is someone that has died. A descendant is someone that would not be here if the deceased had not had any children (natural or adopted).
A dog is decended from wolfs
ascended
CainApes!It
the man of its own
Apes!
It decended from baseball
The Jews.
Your balls drop during puberty. At age 4 they shouldn't have dropped
Guatemala
Europe, Africa and the Americas.
Amy and Dan are Madrigals and are decended from MadelineCahill.
He is descended from Ignotus, the youngest brother of the Peverell family.