Gracie Faver Evolution Class Blog

 Genetic Drift Genetic drift is a change in gene or allele frequencies due to random chance. In the bottleneck effect seen on the top illustration, there are 6 different colors that could represent 6 different species. Some sort of bottlenecking event occurs. An example of this would be a natural disaster like a forest fire. This might kill off some or all of certain species, leaving only a few behind. In this example, only 3 colors (or species) survived. Then, through a process of evolution and selection, the 3 remaining species will continue to reproduce and create a new community of species. In the second image, the founder effect shows when a species moves to a new geographical location and are able to survive, they can also create an entirely new community of species. For example, in the image the mainland has multiple different colors of bugs. One day a green and pink bug fly to island 2 and land there. No other animals are on that island, and the green and pink bugs will be ...

It Gets Complicated Plasticity is the ability of an organism's phenotype, or physical expression of a trait, to change in the presence or absence of certain environmental conditions. To determine an organism's plasticity (let's say a moth whose wings might change colors to match their environment), you would need to establish the trait you are going to study. Once you have established that the color of the wings is the trait you are going to study, gather many moths and put them in a similar colored environment. Document the color and pattern of their wings, and after a select period of time, move them to a new environment (or many new environments) to see if their color or pattern changes in response to the conditions. If a change is noticed, repeat the study for validity of results. Make sure to eliminate outside variables by feeding them at the same time, providing the same amount of light, and ensuring all organisms being compared are the same gender etc. If the organis...

 Genotypes and Phenotypes How does it make sense that selection acts on the phenotype when we know that the genotype is what is passed to the next generation: To answer this question, I think that it is important that we first illustrate the differences between a phenotype and a genotype. A genotype is an organism's genes. This is the molecular makeup of their being, their code for everything that makes them, well, them. Genotypes change throughout generations and are susceptible to mutations and recombination. Both of these factors cause genotypes to shift and change, creating changes in the organism and their offspring. Phenotypes are the physical representation of these genes. We see phenotypes through the traits that an organism has. Someone might have brunette or blonde hair, but they have it due to the combination and order of their specific genome. Examples of phenotypes include colors of petals, skin, and eyes, length of legs, blood type, stem thickness, etc.  When loo...