Chapter 8: Self-Interest (Genome)

•Instruction manuals are frustrating because they never have the one piece of information you need.

• Genes are complicated because they are written by nature and subject to parasitism.

• Junk DNA is found on every chromosome and makes up 97% of the human genome.

• Reverse transcriptase is a common gene that serves no purpose for humans but is essential for the AIDS virus.

•Selfish DNA is a major and unexpected discovery.

• We are full of digital chain letters and warnings about marmalade.

• Our genomes badly need worming.

• Nobody suspected this.

•Mutations in the colour of maize seeds occur in such a manner that can only be explained by mutations jumping into and out of pigment genes.

• In human beings, LINE-1s and Alus have caused mutations by landing in the middle of all sorts of genes. They have caused haemophilia, for instance, by landing in clotting-factor genes.

• The potential danger posed by jumping genes was dramatically illustrated by a sort of natural experiment in the 1950s in the tiny fruit fly, Drosophila.

• One of these species, called Drosophila willistoni, carries a jumping gene called a P element. Somehow in about 1950, somewhere in South America, perhaps via a blood-sucking mite, Drosophila willistoni’s jumping gene entered the Drosophila melanogaster species.

• The P element has since spread like wildfire, so that most fruit flies have the P element now..

• Human beings possess nothing so sinister as a P element at present time but something similar has been found and it is called ‘sleeping beauty’. It has been introduced into human cells but is not yet active..

• What we see in nature is a complex tapestry of self-interest, where genes play the long game and sometimes, seemingly counter-intuitive strategies reveal themselves to be the most successful. For example, a gene might seem to harm a certain host, and yet in the long run it might have been beneficial, as it spread through different species. This has been demonstrated time and again with genetic parasites. Moreover, even in humans, selfish DNA has the potential to cause genetic diseases and yet is still heavily present in the genome.

•In 1984, Alec Jeffreys and his technician Vicky Wilson discovered minisatellites while studying the evolution of genes.

• Minisatellites are stretches of repetitive DNA that are found in the same location on all chromosomes. They vary in length from individual to individual.

• The significance of minisatellites is that they can be used to create a unique genetic fingerprint for each person.

• On 2 August 1986, the body of Dawn Ashworth was found in a thorn thicket near Leicester, England. A week later, Richard Buckland confessed to her murder.

• However, five months after Ashworth’s death, it was discovered that Buckland could not have been the murderer due to a mismatched genetic fingerprint.

• The true murderer was eventually caught when he confessed to another colleague at his bakery job who then reported him to the police.

•D N A fingerprinting has revolutionized forensic science, allowing for the identification of criminals and exoneration of innocent people.

• The technique has been used to confirm the identity of high-profile individuals such as Josef Mengele and Thomas Jefferson’s illegitimate descendants.

• Paternity testing is a common application of genetic fingerprinting, which has led to greater understanding of bird song behavior.

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Related posts:

1. Law 17: Seize the Historical Moment (The Laws of Human Nature)
2. Part 2: Isolate the Victim (The Art of Seduction)
3. Chapter 16: The Capitalist Creed (Sapiens)
4. On Nietzsche’s Thus Spoke Zarathustra Summary (8.4/10)