Answer:
What causes new alleles to appear are mutations and gene flow but mostly mutations.
Explanation:
I believe the answer is the limbic system.
The limbic system is the portion of the brain that deals with emotions, memories and the arousal or stimulation. It consists of the amygdala, hippocampus, thalamus, hypothalamus, basal ganglia, and cingulate gyrus. The amygdala is the emotion center, the hippocampus plays a role in the formation of new memories about past experiences.
Answer:
C
Explanation:
am su that is the answer u need