Answer :
If you walked northward from the equator and noticed a trend of skin color changing by becoming lighter, this is known as Cline.
What is cline?
This is the tendency of a gradient to form in a certain biological trait in organisms that are separated by distance.
The humans separated by distance from the equator upwards, show cline because there is a complexion gradient in their skin tone with those northward from the equator being lighter.
Find out more on cline at https://brainly.com/question/4336906.