I am a Human Biology major, so my understanding of evolution is a mix from a few different perspectives. One is evolution from a functional context in human body systems. A good example of this is how our immune systems function and morphology has changed. Originally humans were thought to only have an innate immune system that could respond to nonspecific antigens and had to continuously identify the same antigens as self or non-self over and over. This was an effective but not particularly efficient system. Eventually humans developed an adaptive immune system that allowed for the marking of foreign antigens with antibodies and for the development of memory cells. This made for a significantly more efficient immune system as the body could recognize previously seen antigens and destroy them much more quickly. Currently we may be seeing further evolution of the human immune system with autoimmune disease and allergy. One common theory around why autoimmune diseases and allergies are increasing in incidence particularly in more developed parts of the world is because the portion of the immune system designated for parasitic infections is rarely used due to the increased sanitation levels in these parts of the world. This could potentially lead to people with less active IgE mediated immune systems having greater fitness in a cleaner world and passing down those genes. The other way I view evolution is through a population perspective. The classic example of this is Darwin’s Finches which developed unique beaks depending on where they were living and what types of food were available there. One thing I found interesting was in the “The 2% Difference” article when it talked about how the main differences between chimps and humans are caused by mutations in transcription factors and genes controlling embryonic cell division. The part about transcription factors was most interesting to me because I mostly think about phenotypic changes coming from point or frameshift mutations in coding regions of DNA. However, like the article mentions a single point mutation would be far more likely to have a significant effect if it occurs in the transcription factor region due to the number of proteins it will affect. A questions I have is that how many of these transcription factor mutations will lead to loss of function mutations. It seems more likely that instead of changing how many times or how the genes are transcribed, it will make it much more difficult for RNA polymerase to bind and none of the genes will be transcribed. Whereas a mutation in a coding region as significantly higher chance of only affecting one amino acid therefore making a gain of function mutation more likely. The other big difference between humans and chimps the article talked about was the difference in genes that control embryonic divisions. This was a little bit confusing in the way that the article explained it. They mention the difference in divisions and resulting number of neurons as the difference in brain power in chimps and humans. This is a confusing and seemingly incomplete answer. We know that humans do not have the most neurons out of all organisms, elephants have more. However, even though elephants are recognized as fairly intelligent creatures there not smarter than humans. So there must be more to brain power than number of neurons whether it’s the number of neurons in certain areas, neuronal connections, or the number of supporting glial cells the articles reasoning is incomplete at best.