Evolution - BIOL520

 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...

  Stripes = D  — for mainland Reduced striping = B and C Stripeless, gray color = A  — for island In Ontario, which in this graph means further into the mainland, the only phenotype recorded is that of           snakes characterized by complete stripes. In the peninsular mainland, the strong stripe phenotype is still very prominent and most popular, but the other phenotypes, reducing stripe pattern and no stripe pattern at all, are present in low numbers. On Kelleys Island, the reduced stripe pattern is most common, while the strong stripe and no stripe at all are low but at the same number. It is noted that Kelleys Island is one of the islands closest to the mainland. The Bass complex Islands have more no stripe phenotypes while the stripe phenotype is lowest in number. Finally, the Middle & Pelee Islands have the largest number of completely no stripe phenotype snakes. The general pattern that emerges is that the further away from the m...

First off, I think it is kind of crazy that evolution is both a theory and a fact. I has always been emphasized to me that it is a theory, but a well supported and generally accepted theory. If I were to go back to my first blog post, I would be more specific in that evolution must be heritable. It has not really occurred to me that there are innate aspects of a person, aspects that a are not easily changed, that are not heritable. My dad is homophobic and has complained that he doesn’t get how people could be gay because if the person is gay, they can’t have kids, and if they can’t have kids, they can’t pass on this trait of being gay. Despite the many issues with his statement, I think one of the key points that I did not know and could not argue at the time is his assumption that being gay is heritable. That’s another thing. I have realized that there are a lot of assumptions I make unconsciously when it comes to evolution. I have never thought about the fact that a lot of my assump...

       Mutation rates do evolve. Mutations occur in genetic material, but the materials — the enzymes and proteins — that reproduce the genetic material can they themselves can be affected by mutation. When DNA polymerase or other proteins involved in DNA transcription are altered, the rate of mutation can change. It is more likely that DNA polymerase would be mutated to make more mistakes than be mutated to be more accurate and make less mistakes. It is common knowledge that the slower the DNA polymerase ‘reads’ and replicates, the more likely it will be to accurate place the correct complement amino acid base. The faster the DNA polymerase works, the more likely it is to make mistakes, and thus mutations, by placing an incorrect base pair. This incorrect nitrogenous base can then be used as the template strand in the future, and more ‘incorrect’ genetic material will be created in the future based off of this one error. There are enzymes and proteins utilized in tr...

            Cloning is important in endangered species, but can be potentially dangerous in species that are not endangered but mass-produced. Too much cloning would end up with a lack of genetic diversity, which could result in genetic abnormalities and possible negative health conditions for the animal. I think cloning can be a very useful tool, but should be used carefully.  The Times article that I read also mentioned that Revive & Restore, the a wildlife conservation group that utilizes biotechnology and helped make the cloning possible, wants to bring back other extinct species, like the Wooly Mammoth. One, it would be amazing if that happened, given that Wooly Mammoths went extinct 4,000 years ago. Two, I can’t but help think of Jurassic Park. Just because we have the means, should we do it? I know Wooly Mammoths are not man-eating dinosaurs, but that does not mean that they would not be potentially dangerous to humans and/or other or...

          Baby Elizabeth Ann, the cloned black footed ferret           Recently, I have read a couple stories of animal cloning in the name of genetic diversity. I think these are interesting topics and relevant to the class. In August of 2020, a critically endangered animal called Przewalski’s horse was cloned from the DNA that had been collected in 1980 and preserved in the San Diego Zoo Global. With conservation efforts, the species was brought back from the brink of extinction and re-introduced to its native grasslands in China and Mongolia. What I think a key point to consider is that almost all of the the horses can be traced back to only 12 predecessors. Conservationists were only able to work with the genetic diversity of 12 horses - that is how critically endangered they were. The new baby that has been cloned using old DNA is meant to contribute genetic diversity into the dwindling species.  In December of 2020...