chromosome 17

Death:
This chapter basically speaks of cancer. It explains to us that cells reproduce themselves at the wrong time. when cells are not stopped from reproducing incorrectly they produce cancer.A gene called TP53, on the short arm of chromosome 17, it is known as a tumor-suppressor gene. This genes are the opposite of oncogenes, which are genes that encourage cell growth. Oncogenes can cause cancer when they are doing work and tumor supressor genes can allow cancer to happen if they are not working. Detecting cancer early is important so we can prevent the cancer from spreading. Ridley explains that in various types of cancers TP53 is mutated very early, which is why chemotherapy and radiation therapy does not always work effectively in late stages of the disease. The chapter is named death for the reason that cancer is so deadly. The accumulation of cancer cells can create tumors over time and since there is no specific effective cure for cancer, it is critical that it is detected as early as possible.

Chromosome 2

Species
In the twentieth century scientists thought there were 24 chromosomes in the human genome. Gorillas and chimpanzees have 24 chromosomes to our 23, because the human Chromosome #2 is a combination of two ape chromosomes. “Humans are an ecological success,” the only competition we have are domestic animals and we have colonized almost all habitats. In this chapter we discovered that humans and chimps genetically are 98% the same. There is no specific time in which there was a separation but scientists have discovered a split in the chimpanzee population. The human species was half of the population which developed a genetic mutation that did not allow breeding between both populations. Along with the human species they brought along different ways of sexual selection from the other two species. Humans brought methods like the monogamous system and attraction to more youthful mates. Monogamy shaped our hunting/gathering habits and a “sexual division of labor”. Ridley explains to us that the difference is found in the genes.