Do conditions overwrite?

Do conditions a lower duration overwrite conditions with a longer duration?

Example: [skill=text]Searing Flames[/skill] and [skill=text]Mark of Rodgort[/skill]

Let's say I cast Mark of Rodgort on a target. I cast Searing Flames on that target, beginning a 6 second burn. Then, I cast Searing Flames again on that target, doing the fire damage and proccing Mark of Rodgort. Does the 3 second burning overrite the 6 second burning from Searing Flames?

yes it does