<span>If
a geological barrier (like a continent splitting apart) separates a
population of primates, then each population will evolve separately to
fit the different conditions of their environments.
As a hypothetical example, if one part of Pangea went north, the
primates on that part would adapt to cold temperatures. If the other
part went toward the equator, those primates would adapt to heat and
direct sunlight. Eventually they would evolve into different species
over many generations.</span>
The answer is "D"
The body's first line of defense is also known as Innate immunity and incudes mucous membranes. Both the intact skin and mucous membranes of the body offer a high degree of protection against pathogens.
A good example is the mucous membrane of the respiratory tract. It is lined up with cilia and covered with mucus. The coordinated beating of the cilia drives the mucus up to the nose and mouth where the trapped bacteria can be expelled.
(Lymph nodes and white blood cells belong to the second line of defense, not the first)
