"Genome" by Matt Ridley review

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Genome by Matt Ridley

Chapter 1

        Although the beginning of life is still somewhat ambiguous to scientists, author Matt Ridley decides to begin the story of the chromosomes. The first chromosome, according to scientists, began by rearranging different chemicals out of entropy into something alive and working. It seemed to multiply instantly and did not stop until the earth went from absolutely nothing to a world of living things. Mankind, with the ability to think and understand the world, is given these abilities by chromosomes, in part. 

        Another question we must ask is: what exists in organic life that causes life? The first answer to this question was proposed by Erasmus Darwin in 1794. He proposed, in his book, that all organic life consists of something he referred to as filaments, and these threads were the secret to life. Of course, many years later scientists continued to research this and discovered the significance of DNA in the evolution of life. Life essentially has the ability to replicate and create order. To do this, there needs to be information that allows these things to take place, which is the principal function of DNA. DNA is a filament of information that makes up a message written in a code of chemicals we know as A, C, G, and T. (Adenine, Cytosine, Guanine, and Thymine.) The interesting thing about this is that the code is literally written out just like English. It is, in a sense, a linear language. Essentially, DNA is the code that identifies us, but the other thing that shapes our characteristics are genes. Genes are a unit of heredity that is transferred from parent to offspring, embedded in our DNA. However, scientist did not know that genes existed or where they were. Many scientists tried to figure out how genes worked, but simply could not do it until one scientist proved, through an experiment, that our DNA is comprised of genes and is transferable. 

The largest chromosome of the 23 is labeled as chromosome 1. This chromosome, along with the rest, has arms. On the long arm of chromosome 1, we find a code. This code contains 120 letters of the 4 genomes: A, C, G, and T written in a paragraph to from a single gene. The thing that makes this gene so special is that it is constantly being duplicated into what is referred to as RNA. Then, RNA translates DNA into proteins. What we see here is an amazing system within our bodies that makes us who we are, and it all comes from genes within our DNA. 

RNA once ruled the earth as we know it. Scientists believe that the first single cell ever originated from a thread of RNA that developed into a thread of DNA, which later started making more RNA. This RNA eventually started to develop proteins three letters at a time, which makes up the genetic code. Scientists named this single cell Luca: Last Universal Common Ancestor, which they believe evolved into everything we know today.  

Chapter 2 

“We have built a scientific house of cards on the flimsiest foundations of evidence, but we have reason to believe that it will one day be testable.” Interesting enough, scientists are still unable to prove this due to lack of hard evidence, but they still use this theory in all current research regarding the origin of life. This chapter of Genome focuses on Chromosome 2, which according to scientists holds the history of the human race genetically. The chapter begins by providing some history regarding the discovery of 23 chromosomes. Scientist after scientist has studied chromosomes throughout history and concluded humans have 24 chromosomes. However, there are actually 23, discovered in 1955 by two scientists that simply double-checked the facts. They plainly saw 23 chromosomes, which is indeed the true number of chromosomes in humans. Chimpanzees are actually the species that hold 24 chromosomes. This similarity is not a coincidence because scientists believe that the two ape chromosomes merged together into one resulting in human genome. This is chromosome 2. 

        Matt Ridley makes it clear that he strongly believes in the theory of evolution; that human beings' common ancestor is indeed the apes. Humans and the chimpanzee share bone structure, immune systems, digestive systems, vascular system, nervous system, and more. The genomes of chimpanzees and humans are extremely similar, unsurprisingly. To understand the complexity behind this, Matt Ridley tells the story of how the humans emerged from an isolated group of primates. The story begins with this isolated group living on an island. Suddenly, the chromosomes merge, creating a mutation. This means they can no longer reproduce with their original species, only amongst themselves. At this point,  they are already becoming something new and different. They can now walk on two legs, have become less hairy, and sweat. This allows them to move on away from the shady forest and out into the world. Eventually, this new species of “human” becomes more carnivorous, has developed a sense of desire for younger mates, and have even assigned life duties to males and females for everyone’s benefit. Humans are essentially becoming more organized and far more complex than the average ape, due to the merging of the aforementioned chromosomes. Towards the end of the chapter, Ridley concludes by explaining that, although all these facts are most likely true, there is still no hard evidence. For instance, the genome does indeed hold 4 billion years of history, but there is no way to read it right now. He also explains how “mind-bobbling” it is that a simple genetic code can differentiate today’s human beings with chimpanzees.

Chapter 3

        Ridley opens with a scientist named Archibald Garrod, who was a medical researcher in 1902 who focused on a disease called Alkaptonuria. The disease was not serious, but it leads him to think about where this disease comes from and the possibility of its genetic implications. He later went on to discover that the disease was found in the lineage of families and could even reappear after a generation that did not have the illness. Research proved that the disease was caused by a faulty gene passed down that produced a defective enzyme. These revolutionary facts lead Garrod to establish a hypothesis of “inborn errors of metabolism”, but more importantly, allow him determine that genes were protein-making devices. This was unknown to scientists previously, and it would take 35 years until this discovery became well-known throughout the scientific community.

        Garrod also established the fact that every protein in the human body is made from a gene, and genes are inherited from prior generations. The origin of Garrod’s experiments is actually based off of Christened Johann Mendel’s research of 1860. “He knew that he had discovered something profound about heredity: characteristics do not mix.” Mendel is considered the father of genetics because he essentially discovered that there are dominant and recessive genes in the human genome, meaning that traits do not disappear. He began his research by crossbreeding pea plants and observing visible traits that would be passed on from different generations. This would explain why offspring have visual traits that may be inherited from previous generations and not specifically seen in parents. This also supports Archibald’s future research that disease can be inherited from prior generations.

        Mendel and Garrod both discovered the fundamental truths about genetics, but they still have not explained mutations, which fell in line with Darwinism. An in depth study of mutations conducted by Hermann Joe Muller, George Beadle, and Edward Tatum from 1926 to 1940 proved, “mutations were altered proteins made by altered genes.” Genes seem to be the key to understanding heredity and mutations, but what are genes made of? Scientist were still unaware of this crucial fact until 1953, when James Watson and Francis Crick found that DNA is the building block of genes. By the 1960s, the study of genetics became more significant as the quantity of research continued to grow.

Chapter 4

        This chapter is a chapter of fate. Ridley begins by talking about how a gene specifically located in Chromosome 4 can cause Wolf-Hirschhorn Syndrome. Everyone has this specific gene, but those that are missing it end up suffering from the syndrome. However, if the gene has a mutation, it could cause Huntington’s Cornea. Huntington's Disease is a brain disorder that cause people to lose their ability to move, walk, and communicate. It essentially causes people to lose their sanity, and many of those affected die as a result of a number of a number of causes. According to Ridley, the mutation is caused by a codon spelled CAG that constantly repeats itself. The rules are, if the codon repeats thirty five times or lower, than the mutation will not take effect since it is present in every genome. However, if it breaches thirty nine times or more, than Huntington’s Disease will take effect and will last between 15 and 25 years.

        “Your destiny, your sanity, and your life hang by the thread of this repetition.” When Huntington’s Cornea killed a famous folk singer named Woody Guthrie in 1967, his widow began a committee to fight the disease. This committee was joined by a doctor named Milton Wexler, whose family was suffering from the disease. Her daughter, Nancy, was at risk for inheriting the disease. Convinced of her destiny, Nancy set a goal to locate the gene that was causing the mess. However, locating a gene in a code of billions is not easy. She had to track down and research generations, travel the globe for blood samples, then scan through the codons to find the gene. She was assisted by a scientist named Jim Gusella who was in charge of finding the gene within the DNA provided. This process took years to complete. But by 1993, the gene was found, nearly 30 years later. Eventually, it was discovered that Nancy did have the disease, although the effects had not been shown at this point.

Chapter 5

        The fifth chapter begins with a lie. Matt Ridley begins by saying he lied to the reader in the past chapters, saying the genome of a person is simple. For instance, in the past chapter, he talked about how people are either tall or short, as a pea is either smooth or wrinkled. In reality, genes are much more complicated and blended. Characteristics are not made up of single genes, but of several. Ridley then goes on to say that Chromosome 5 is where this process occurs, to an extent.

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         Chromosome 5 is where the asthma gene is located. Asthma affects many people worldwide, especially children. Much research has been done to assess the causes or factors that contribute to asthmatic symptoms. However, Ridley later explains that environmental factors that surround the individual are responsible for asthma. People who live in urban areas are more prone to have   , but the interesting thing is that Urban areas are also fairly clean. Interesting enough, people who actually keep themselves clean have a higher chance of having asthma. Biologically, people's immune systems are constantly ready to encounter mycobacteria that is ...

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