The different races came from the descendants of Noah. It does not take long for genetic traits to become dominant based upon geographical location. Take, for example, people who would live in Africa where the sun is very direct and there's not as much cloud cover. People with darker skin would survive better because they would not be sunburned and develop skin cancer the way lighter-skinned people would.
On the other hand, people in the northern regions, where the sunlight is less direct, would need more vitamin D which is produced by the sunlight hitting the skin. Vitamin D prevents rickets, which is the softening of bones which can lead to fractures and breaks. But people with darker skin in more northern, colder climates would not be able to produce as much vitamin D, and so they would not do as well as people with lighter skin.
The descendants of Noah had all the genetic material necessary to produce the various so-called races as they moved out across the land and went to different locations. Given enough time, those genetic traits that manifested and aided in survivability became dominant, and those genetic traits that manifested but did not help survivability were eventually wiped out.
Please note that CARM does not affirm the theory of evolution which states that people evolved from lower life forms. But God, in his great wisdom, provided enough genetic information in our genes to aid us in adapting to various needs. Furthermore, CARM's position is that there is only one race, the human race. We have different shapes, sizes, and colors. But, we ought to see yourselves as being made in the image of God (Genesis 1:26) worthy of respect and honor. We are one race.