The border across which genes can flow between two populations is called the contact zone. Natural selection operates to produce changes in populations.
hybrid zone
The boundary between stalled air masses is called a stationary front.
divergent evolution
-transform boundary -convergent boundary -subduction zoone -divergent boundary -mid-ocean ridge -rift valley ...these are some possible answers to your question.
Plant populations
It is called speciation.
border: is the name of the passage way between two countries; such as: I am going across the border between the US and Mexico at El Paso. border: is the name called the edge of a table cloth or skirt in the hem of dress; such as: The young boy wiped his mouth on the border of the tablecloth.
They are called Coyotes.
It is called the border. There are border crossing set up on most of them to control who comes in or out of the country.
It is called a border.
The border line between India and Nepal is called the India-Nepal border or the Indo-Nepal border.
divergence / divergent evolution
Usually there is no empty space. The border crossing is right ON the border. Once you cross the border you are in the other country. In Europe today there are no borders since the creation of the European Union. In the 1970's I crossed into Italy from Austria and there was a border then, but it was a simple matter of going across.
The Border between the two countries separating Russia and China is just that a Border line.
The boarder between two plates is called a boundary.
It is simply called the England/Wales border but it does roughly follow the line of Offa's Dyke, which is an ancient earthwork which once marked the border between King Offa's kingdom and Wales.
No, otherwise it wouldn't be called Members' Area.
A cam border is the plain strip of fabric about one to two inches in from the edge of the towel. A decorated cam border gets a new name: dobby border.