Survival of the Sickest Chapter 6 Summary

Survival of the Sickest

Chapter 6

READING ASSESSMENT

This chapter of Survival of the Sickest begins by talking about Edward Jenner who was the first person to successfully discover a vaccine for a dangerous disease. The chapter then continues to discuss how humans are initially formed with only one cell, which is the product of a sperm cell and an egg cell. The chromosomes within the cells carry the instructions on how to build us. 

The chapter then explains how only 3% of DNA actually carries instructions on how to build us, while the other 97% does not do anything. Scientists originally assumed this DNA was "junk" and ignored it completely until the past couple of decades. Scientists then discovered that this " junk" DNA actually carried jumping genes and was related to viruses. These viruses turned out to be retroviruses. It was then believed that jumping genes actually descended from retroviruses and that are genomes have been modified by one particular retrovirus that made it easier for us to infected by other retroviruses. Therefore,  this "junk" DNA actually provided us with the code for our evolution from our primate ancestors. 

The chapter also talked about mutations within genes. The potential for evolution initially occurs when a mutation happens during the reproductive process of an organism. The effects of mutations are usually negative to the organism; however, they can prove to be beneficial. By studying mutations, scientists also discovered that instead of having 100,000+ genes, we actually have around 25,000 genes that serve multiple purposes and can be reshuffled with other genes.

The chapter also debunked rumors about inherited acquired traits and further explained jumping genes, which I talked about earlier in the summary. The chapter also discussed the genome's ability to gamble on mutation when survival situations became drastic. By gambling on mutation, the genome could end up creating a much stronger and better adapted organism that could possibly survive instead of die. There was also discussion of the development of antibodies and how once they are acquired they remain with the body and help to fight off future diseases.

This was a very interesting and complex chapter of Survival of the Sickest. The main focus of the chapter was genes and their different functions within an organism.