Kalissa's Blog

This image displays the difference between Genetic Drift and Natural Selection. Genetic Drift is due to random chance where an even takes place to alter the allelic frequencies in a population. Alternatively, Natural Selection has more of a cause and effect behind it. In this instance, the brown rabbits do not blend into their environment as well as white bunnies. They fall victim to predation more frequenty leading to a shift in the bb allele frequency.

To understand what plasticity is and how to determine what makes a trait "plastic" is to start by defining the term. Plasticity is an organism's ability to change their phenotype as a response to an environmental condition change. With that established, there are many ways you can determine if a trait is plastic. First, you would have to uncover if there are any environmental conditions that would impact the organim's trait. Next, you could do a controlled experiment where you alter a specific condition to see if that changes the organism's traits or you could look at different species that are closely related or the same species in different environments to see if the trait is impacted by different environmental conditions. If that trait differs significantly between environments, then it would be considered plastic. This would then need to be compared to the genetic variation to determine that this is not due to genetic variation. If all of this leads to the con...

In selection, there are many aspects that play a roll beyond the genotype of the organism. In many cases, this relates to environmental factors pressuring organism's survival and reproduction. Those with traits better suited to their environment, like behaviors and physical characteristics, have a higher chance at surviving to produce offspring. Then, the genotypes associated with the better suited phenotypes are more likely to be passed on to offspring allowing the organisms in future generations to continue being selected for as long as external conditions continue to select for that trait. This pushes evolution foward. Use the dots in this as an example, the purple color is selected for (displayed by the higher number of offspring) due to the purple environment. The purple coloration allows them to blend into the purple environment better allowing them to continue to survive and reproduce.