Block Mutations vs. Single Letter Mutations

Throughout chapter one of the book, Sean Carroll mentions two distinct ways in which mutations can arise (specifically p 33). A simple manner is single-letter mutations, where letter by letter genes are changed, creating different genes, creating different proteins, creating different phenotypes, creating selective advantages. Another mode by which genetic mutation can occur is by entire segments of genetic material relocating themselves within the genome, through transposition (in other words, these genes are transposons). We see this latter type in the development of the antifreeze gene, coding for proteins that prevent the icefishes' blood from freezing.
Given your knowledge of the various effects of different types of genetic mutations, discuss the possibilities and implications that follow with each type of mutation.

Traits from Common Ancestors

Sean Carroll says that there exists a "descent of all living species from common ancestors," implying that different groups of living things share certain traits which came from a common ancestor between the groups. Using your knowledge from previous units we have studied, choose EITHER two phyla of animals OR two kingdoms and note at least three similarities derived from a common ancestor between the two groups, and three differences between the two groups.

Prompt III

Genetic diseases are found in all human populations. Some diseases such as Tay-Sachs disease and sickle-cell disease occur more frequently in certain populations such as Ashkenazi Jews and African Americans respectively. Does this phenomenon indicates that the genetic mutations for these particular diseases occurred in our hominid ancestor or that the mutation arose independently after the human race had diversified?   

Huxley vs. Darwin - Natural Selection

Biologist Thomas Huxley believed that natural selection took place on a bloc-by-bloc basis, essentially that evolution took place involving large discontinuous differences among individuals. How does this differ with natural selection proposed by Darwin? Which type of selection is correct? Why?

Antarctic Icefish

Describe the major anatomical developments that occured to certain species of fish during the time that the oceans cooled significantly. What anatomical developments specifically occured during the evolution of the Antarctic Icefish? How did the environment affect these changes?