As you increase in elevation, there is less air above you thus the pressure decreases. As the pressure decreases, air molecules spread out further (i.e. air expands) and the temperature decreases. If the humidity is at 100 percent (because it's snowing), the temperature decreases more slowly with height.
Answer:
The scientists believe that they arose in Africa and spread to the rest of the world.
Explanation:
A is not correct because the Homo sapiens is not the earliest ancestor of moern humans, but it is the latest.
B is not correct because such evidence is lacking, and even though the Homo sapiens mixed with other hominids in Eurasia and sub-Saharan Africa, they were not of the same species.
C is correct because the evidence suggests for now that the Homo sapiens arose in Africa, and through several migration waves spread out on the other continents.
D is not correct because the Homo sapiens has not been replaced by any other species, as they are the species nowadays known as humans.
I have no idea, but I wouldn't use Wikipedia.. The "facts" on there aren't always true. That's why we aren't allowed to use it in my high school.