Rin's Evolution Blog

 Genetic drift is a random change in allele frequencies within a population. This change is often due to chance events like the bottleneck or the founder effect. The bottleneck effect occurs when a population's size is dramatically reduced, leading to a loss of genetic variation. This can happen as a result of things such as natural disasters, habitat loss, or overhunting. However, in the founder effect, a small subset of a larger population breaks off and establishes a new population, bringing only a fraction of the original genetic diversity.      Genetic drift is often confused with gene flow. In gene flow, we can see the transmission and introduction of genes across populations, but in genetic drift, it is simply the changing of allele frequencies. Genetic drift is also not natural selection, as it does not favor traits that enhance survivability. 

     Phenotypic plasticity is an organism's ability to change its phenotype, or anatomical trait, in response to environmental conditions. Plasticity allows these organisms to better adapt to constantly changing environments, helping them survive and reproduce even in new conditions. While the phenotype may change, the genotype encoding the trait does not. An example of this can be seen in arctic foxes who have a brown coat in the summer and a white coat in the winter, allowing them to better blend in with their environment as it changes.      To test if a trait might be plastic, you must first determine which environmental factor influences the trait. You could then have a control and several experimental groups exposed to different conditions to activate the phenotypic change. If you wanted to test if the fur change in arctic foxes is an example of phenotypic plasticity, you could put some foxes in various environments of different colors and temperatures...

     Natural selection acts on an organism's phenotype rather than its genotype. A phenotype is an organism's observable traits, such as color, size, height, behavior, and more. The genotype, on the other hand, is the specific alleles that make up an organism. The phenotype acts directly with the environment, resulting in natural selection acting on it, passing favorable phenotypes, and thus their genotypes, on to the next generation.      In a population of bears, white bears have an easier time surviving in their environments, and they have a higher success rate in mating. While the phenotype of white fur is what is being acted on by natural selection, the genotype encoding this observable trait is what is being passed on to future generations.