The correct answer is it decreases genetic diversity only by reducing population size.
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The great explanation for this is a bottleneck effect, which is an extreme example of genetic drift. The bottleneck effect occurs when the size of a population is reduced due to a catastrophe. When it happens, only a small, random number of individuals survive the event and pass through the bottleneck. Thus, the genetic composition of the random survivors is now the genetic composition of the entire population which means that the genetic diversity is reduced.</span>
The reward system in the brain is the center of wanting and pleasure, and is the main cause of repeated actions because of the release of some neurotransmitters which does ensure the survival of one's self and offspring. The behavior is a part of organism and organizational level, and neurotransmiters are part of the cellular level.
I learned this long ago, I think it's either Mitosis or cell division, this is when one cell divides to make 2 cells and those 2 cell divide to make 4 cells and those 4 cells divide to make 8 cells and so on.
Genetic variation
Is the best term to use