There are countless examples, but one anecdote I can throw you is a couple I know, both of whom have one parent who was adopted, and thus are ignorant of about

There are countless examples, but one anecdote I can throw you is a couple I know, both of whom have one parent who was adopted, and thus are ignorant of about half their collective genetic heritage. They were getting ready to have children, and wanted to make sure they weren't prone to any “surprises”. Google is successful because it’s useful. These tests are useful. blah blah