Simplify the following text for a Grade 9 native English-speaking person.
Original: The relative distance between two genes can be calculated by taking the offspring of an organism showing two linked genetic traits , and finding the percentage of the offspring where the two traits do not run together .
Simplified: The relative distance between two genes can be calculated using the offspring of an organism showing two linked genetic traits . The percentage of offspring where the two traits do not run together is noted .