TOP 5 STRANGE SMELLS: 1  1. Dead Animal. 2  2. Something Smells Fishy. 3  3. Sewage. 4  4. Moldy and Musty. 5  5. Rotten Eggs. 6  For tips on saving money and energy this winter, take a look at our previous blog posts:
Genetic drift is the change in the relative frequency in which a gene variant (allele) occurs in a population due to random sampling. That is, the alleles in the offspring in the population are a random sample of those in the parents.
Bottleneck Effect. One specific cause of genetic drift is the bottleneck effect, or population bottleneck. The bottleneck effect occurs when a larger population shrinks significantly in size in a short amount of time. Usually, this decrease in population size is generally due to a random environmental affect like a natural disaster or spread of disease.