Parker Jonas was born on November 11, 2010, but his presence in Salem caused drama well before that date. Parker's mother, Chloe, had a one night stand with Philip and became pregnant. Carly found out about Chloe's affair and forced Chloe to have a paternity test. The test named Philip as the father. However, Caroline changed the test results before anyone, including Chloe and Philip, saw the results. By the time Chloe gave birth, everyone believed Daniel was Parker's father. Daniel and Chloe took Parker home to raise him together.
However, on the day of his baptism, Caroline burst into the church and announced that Philip was Parker's biological father. Daniel left Chloe and asked her and Parker to move out immediately. They relocated to another apartment in Salem.
Philip turned his attention to Chloe, as she was having some bad problems with depression after Daniel left her. Philip even rescued Chloe after she tried to commit suicide by jumping in the Salem river. After her suicide attempt, Chloe signed full custody of Parker over to Philip in order to avoid having child services put Parker in a foster home. Chloe continued to decline and during a drunken rant to Kate, threatened to take Parker and no one would ever see him again. Fearful that she would make good on her threats, Philip took Parker and moved to Chicago. Chloe eventually got herself together and move to Chicago as well to be around Parker.
But, in January 2013, Chloe returned to Salem with news. It turned out that Stephanie Johnson had also known about Chloe and Philip's one-night-stand and had an interest in determining who was Parker's biological father. Stephanie was dating Nathan Horton, who was really in love with Melanie, who was married to Philip.
Stephanie knew that if Chloe's baby turned out to be Philip's, Melanie would leave Philip and thus be free to be with Nathan. So, Stephanie asked her friend, Ian, to hack into the computer records so that she could know who the father was and prepare herself for the potential fall-out.
What Stephanie didn't know was that Ian was also in love with her. So, while he did hack into the hospital computer system, he did so to change the test results from Daniel to Philip, in hopes that the above described partner swap would take place and Stephanie would be single. He made the swap while Stephanie's back was turned, so that when she looked at the screen, she saw Ian's altered results -- showing Philip as Parker's father.
After Ian changed the results, Caroline entered the picture. She had access to medical records because was a hospital volunteer in the billing department. She saw Ian's altered test results and thought that Philip did not deserve to be a father because she did not believe that any Kiriakis would make a good father. She also didn't want Stephanie to loose Nathan, so she switched the results back to say that Daniel was Parker's father. But, no one knew that Caroline was actually switching tests that had already been switched.
A few months later, Ian entered a substance abuse treatment program. While going through the process of making amends, he called Stephanie and told her what he'd done. Stephanie called Kayla and Chloe. Chloe insisted on an additional paternity test. And everyone learned that Parker was always Daniel's son.
Chloe briefly tried to reunite with Daniel, using Parker as leverage. But, Daniel did not return her advances. Chloe returned to Chicago to live and she and Daniel share custody of Parker.