Evolution - BIOL520

     I am going to write about polycystic ovarian syndrome, or PCOS, because I recently found out that I have PCOS. If you don’t know what PCOS is, it is a hormonal imbalance in women and named after the many cysts that form in the ovaries to cause this imbalance or as a result of this imbalance. It is characterized by higher levels than normal of testosterone, irregular periods, hirsutism, weight gain, balding, and acne. The exact cause is unknown. Insulin resistance is associated with PCOS and could be either/both the cause or result of the syndrome, and genes could be a potential factor. In my Human Body class today, we literally discussed endocrine disrupting chemicals (EDC) that are ubiquitous in our world, so EDCs could also be a major factor. From my online investigations, it seems that PCOS is not actually a disease of civilization but an ancient disease, but the negative effects of the syndrome are exacerbated by the current environments.  There is evidenc...

  I always thought that natural selection was the strongest, most prominent and popular factor. I have learned how influential and powerful genetic drift is, especially quickly fixing traits/genes in a population. I also learned a lot more details about sexual selection that I have never considered before. It didn’t necessarily surprise me, it made sense, but I just have not thought about it before. Also, I want to say that for my response to the very first prompt, “Is evolution a fact or theory?”, I said a theory because that is what a biology professor at K-State had taught us in one or our classes — no joke. I have never considered it to be both before. I have learned that there is something other than dominant-recessive. I can’t think of what it’s called off the top of my head (also its 11pm at night as I write this), but that is very important to consider: not all allelic relationships are dominant-recessive. I learned that I am still pretty great at interpreting graphs. I got...

 Just before the winter break of 2019, I stopped working on my school work and thought, “This is bullshit. I should be with my family right now. It’s ridiculous that I have to be away from them in order to get an education.” And then I put my nose back to the grindstone. I definitely got my wish. I was super happy to be home during most of the Spring of 2020 with my family. I was happy to help my co-workers during the super busy times we had during the initial quarantines of covid. Things were straight up crazy. Unfortunately, I think these are the only good things I can find from 2020. Oh, I also read Circe by Madelline Miller — I loved it so much. If you read my first blog, you’ll know that I love Greek mythology. Her take on the Witch of Aeaea was excellent. Anyway, although I was glad to help at work, I took on too much work time, and I fell behind in my studies a little bit. Also, it is harder to learn at home and stay focused. My dad is immunocompromised, so it was also hard...

  Genetic variation is maintained in populations because mutations occur all the time. Though most of these mutations are neutral, they still present variation in the allelic frequencies in a population and thus genetic variation. Some mutations are negative and will be selected against, which also alters the allelic frequency and genetic variation. Some mutations will be favored, and natural selection will increase the frequency of this allele, thus changing the genetic make-up of the population as more of this allele is reproduced do to its beneficence. Genetic recombination can lead to genetic variation. I recently watched a video that explained that eye color is more complicated than we thought. I was taught in school that if a blue eyed person, who had homozygous recessive bb alleles, reproduced with a homozygous dominant brown eyed person, who had alleles represented by BB, there child would have to have brown eyes. The only outcomes for children that they would have would be...

 Neutral theory is a mechanism other than natural selection which can lead to evolution. It is the primary factor is genetic drift. Most mutations are deleterious and will disappear out of a population due to their lack of beneficence. Some random mutations will be advantageous and be kept in the population. Still, other mutations will neither be deleterious nor especially beneficial but neutral. This is neutral evolution. Genetic drift determines if these neutral mutations stick around or not in the population. Both theories describe mechanisms of evolution, and these mechanisms can coexist. I believe Kimura thinks only genetic drift is the driving mechanism, but we know this to not be entirely true. Not ever mutation will be subject to natural selection, and not every mutation will be subject to neutral selection. For neutral theory, changes in frequency and the fixation of a mutation occurs by random chance. In natural selection, mutations that are especially beneficial are acti...

  Advantages of inbreeding include the prevention of genetic recombination, which would be beneficial given the genomes of both parents were absent of all possible deleterious alleles. Additionally, specific traits can be selected for via inbreeding, and these traits would be fixed quickly. This is the case in selecting specific traits of dogs. If the phenotype of a heterozygous genotype were not beneficial for the organism and either homozygous allele were preferable, inbreeding would be advantageous because it causes the creation of more homozygotes in a population. If you think about it, two individuals who have the same alleles, if they combine their genetic information, these two similar alleles, then their offspring will be homozygous for this allele. This is what causes the drastic amount of homozygosity in the population. If enough individuals in the population interbred until the point that only homozygous individuals existed and their genomes were purged of deleterious al...