Ashley's Evolution Blog

 Dementia and Alzheimer's are diseases that are very important to me. I work as a CNA so I have to deal with people with both dementia and Alzheimer's in a senior living facility. It can be very difficult to communicate with them, as well as see firsthand how it affects their families. Alzheimer's is known to be genetic, and I have seen this in my family with my grandpa, my great uncle (his twin), and my great grandma all getting this disease. In addition to genetics/family history and age, there are other factors that have been linked to this disease. Head injury is one factor that has been linked to this disease. This can be anything from playing sports to hitting your head in a car accident. Trauma to the brain is not good in any situation, but it has been connected to an increased risk in developing Alzheimer's. This really stuck out to me because I played soccer for 14 years growing up. I used my head (on purpose and accident) many times while playing. Side note - ...

  This past year I have grown more than I ever have. When we got the second week of spring break I only felt excited to get a longer time to relax. However, once the stay at home orders took place everything started to feel more real. Instead of hanging out with friends and going on vacation this summer, I started working as a CNA. I was able to take three summer classes, work full time, and worked on myself to figure out what I wanted to do with my life. I found a love for health care while working at a senior living facility and decided that I wanted to go to medical school to continue to help others. I had a lot of time to explore this decision and gain hundreds of contact hours since all I did was go to work and do school. I spent a lot of time alone, which is something I never really experienced before. I learned to have fun without needing to be with other people, and I also spent countless hours on TikTok. I have changed and matured a lot and learned to do more things on my ...

 I assume something like this mating pattern seen in Microphis deocata evolved due to advantages that gives offspring when females are the ones courting the males. This is a pretty abnormal scenario in a natural population, as it is usually the males courting the females. In this species of pipefish, the males are the ones who carry the fertilized eggs, which the male will fertilize in the females belly. The female then deposits them into the male's pouch, who will then carry them until they hatch. Since the males who are the ones carrying the eggs, it makes sense that the females would be the ones courting them. This is the same pattern we see when it is the females who bear the children or carry the eggs.

I think that one major reason genetic variation is still present is because oftentimes the strength of selection is not strong enough to completely eliminate a certain trait. While some are more advantageous to have, other traits are still able to survive and reproduce enough to maintain that trait being present in the population. There are different levels of selection, and depending on how strong it is will determine how much variation there is in a population for that trait. Mutations will also always arise in populations and there is often a new advantageous trait to have. Generally if these mutations are advantageous, they may be able to fixate in the population. If traits are constantly changing, then there will always be variation in a population. It would be very difficult for all members of a species to obtain a trait if the alleles for this trait change often. As seen in some R exercises, phenotypes that are not advantageous may still be difficult to eliminate from a populati...

  The theory of neutral evolution refers to random molecular level evolutionary changes that are caused by mutations of nucleotides. On the other hand, evolution by natural selection implies that individuals with the most advantageous phenotypes, who are better adapted to their environment, will pass their genes on to their offspring. One main difference is that neutral evolution focuses on a genetic level, the nucleotides of the genome, while the phenotype is what impacts natural selection. These driving forces of natural selection are based on fitness, and the phenotypes that are selected for will be more likely to pass on their genotype. The opposite is true for deleterious genotypes, as their phenotype is not selected for it will removed from the population. The neutral theory does not take into focus the effects of natural selection, just genetic drift. Alleles have the ability to become fixed if they are neutral or advantageous, which is not as prevalent in the theory of evol...

     I used to only think about inbreeding when it applied to humans, and how this often lead to genetic diseases, but never thought about why this is so or the other affects it had. I now know that inbreeding affects the HWE, but not evolution. This is because inbreeding causes an excess of homozygotes and does not allow for the prediction of genotype frequencies from the allele frequencies. In humans, inbreeding causes genetic disorders that are often homozygous recessive diseases. Additionally, inbreeding may occur in species of animals that are endangered or are kept very close together. Plants self-fertilizing is very common as well, but this is not often seen as a negative thing.     Some possible benefits of assortative mating may be the fixation of beneficial alleles in a population. In some cases, it may be more beneficial to be homozygous and inbreeding would avoid having an unsuccessful, heterozygous offspring.     In each situation, it high...