Gene
I recently read a book "The Gene: An Intimate History" from Siddhartha Mukherjee. I noted down some of my observations from the book.
1 DNA contains the hereditary information in our body. All of body cells have the same DNA.
Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.
3 DNA is like book of genesis. All the instruction for all the biological processes in body is written in DNA.
4 In computers information is stored as sequences of zero and one. All the information that you store in computer or every code that you run is translated into sequences of zero and one, before storage or execution. Similarly DNA is programming language of life.
5 In your computer hard disk lots of sequences of zeros and ones may be stored, but programs stored on your computer do the actual work. Similarly in human DNA, only three percent of DNA is the actual coding portion. Coding portion of DNA is translated to proteins by human cells. DNA corresponding to each protein is called a gene.
6 All chemical reactions in the body are controlled by proteins. They trigger, control and stop the chemical reaction. Nearly every cellular function - metabolism, respiration, cell division, waste disposal, growth, even cellular death- requires protein.
7 DNA is long sequence of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T), Similarly Proteins are long sequence of twenty amino acids. Code of DNA is translated to code of protein by cells. Scientist have mapped every triplet combination of DNA bases to a corresponding amino acid.
8 Every cells of body has same DNA but there so many many different cells in the body. Heart cells pumping the heart, Neurons transferring the neural signals and so many more. Every cell know which protein to create and where and when to use. And this information is also an encoded in DNA. DNA's contains code for when and how to create the proteins depending on situations. And proteins themselves trigger specific DNA code as per instructions of DNA code.
9 Genes contains all code for construction and operation of human body but human DNA encodes only about 20687 genes in total - only 1796 more than worms, 12000 fewer than corn and 25000 fewer genes than rice or wheat. So sophistication of human beings is not due to more genes.
10 Our DNA not only influences obvious genetic attributes like height but also IQ, attitudes, susceptibility to diseases etc. However influence of DNA on our physical and mental traits is tempered by environment and luck/serendipity.
11. Identical twins carry the same genetic code. So they are used to study impact of genes on physical and mental traits. In one scientific study they studied identical twins who had been separated at birth. They found striking differences among identical twins, even among twins separated at birth.
a) For people raised in the same culture with the same opportunities, differences in IQ reflected largely differences in inheritance rather than in training or education. Using data from four different tests, scientists came up with a heritability score of 0.75 for intelligence, suggesting the strong influence of heredity.
b) One investigation, found that an identical twin with a criminal co-twin was more than 1.5 times as likely to break the law as a fraternal twin in the same situation, suggesting that genetic factors somehow set the stage for criminal behavior.
c) Social and political attitudes between twins reared apart were just as concordant as those between twins reared together: liberals clustered with liberals, and orthodoxy was twinned with orthodoxy. Religiosity and faith were also strikingly concordant: twins were either both faithful or both nonreligious. Traditionalism, or “willingness to yield to authority,” was significantly correlated. So were characteristics such as “assertiveness, drive for leadership, and a taste for attention.”
c) Novelty seeking and impulsiveness were found to have striking degrees of correlation. Experiences that one might have imagined as intensely personal were, in fact, shared between twins. “Empathy, altruism, sense of equity, love, trust, music, economic behavior, and even politics are partially hardwired.”
12. The picture that emerged from the study was not that reared-apart twins were identical, but that they shared a powerful tendency toward similar or convergent behaviors. What was common to them was not identity, but its first derivative. Personalities vary four archetypal dimensions: novelty seeking (impulsive versus cautious), reward dependent (warm versus detached), risk avoidant (anxious versus calm), and persistent (loyal versus fickle). Twin studies suggested that each of these personality types had a strong genetic component.
13 In twin studies they found several twins with remarkable similarities
a) Born in Piqua, Ohio, in 1939, Jim Springer and Jim Lewis were put up for adoption as babies and raised by different couples, who happened to give them the same first name. When Jim Springer reconnected with his brother at age 39 in 1979, they uncovered a string of other similarities and coincidences. Both men were six feet tall and weighed 180 pounds. Growing up, they'd both had dogs named Toy and taken family vacations in St. Pete Beach in Florida. As young men, they'd both married women named Linda, and then divorced them. Their second wives were both named Betty. They named their sons James Alan and James Allan. They'd both served as part-time sheriffs, enjoyed home carpentry projects, suffered severe headaches, smoked Salem cigarettes, and drank Miller Lite beer. Although they wore their hair differently—Jim Springer had bangs, while Jim Lewis combed his hair straight back—they had the same crooked smile, their voices were indistinguishable, and they both admitted to leaving love notes around the house for their wives.
b) Daphne Goodship and Barbara Herbert were twins from England. They had been born to an unmarried Finnish exchange student in 1939, and their mother had given them up for adoption before returning to Finland. The twins were raised separately—Barbara, the daughter of a lower-middle-class municipal gardener, and Daphne, the daughter of a prominent upper-class metallurgist. Both lived near London—although, given the rigidity of class structure in 1950s England, they might as well have been brought up on different planets. Yet in Minnesota, Bouchard’s staff was repeatedly struck by the similarities between the twins. Both laughed uncontrollably, erupting into peals of giggles with minimal provocation (the staff called them the “giggle twins”). They played pranks on the staff, and on each other. Both were five feet three inches tall, and both had crooked fingers. Both had gray brown hair; both had dyed it an unusual shade of auburn. They tested identically on IQ tests. Both had fallen down the stairs as children and broken their ankles; both had a consequent fear of heights, and yet both, despite some clumsiness, had taken lessons in ballroom dancing. Both had met their future husbands through dancing lessons
c) Two other women, also separated at birth, emerged from separate airplanes wearing seven rings each. A pair of male twins—one brought up Jewish, in Trinidad, and the other Catholic, in Germany—wore similar clothes, including blue oxford shirts with epaulets and four pockets, and shared peculiar obsessive behaviors, such as carrying wads of Kleenex in their pockets and flushing toilets twice, once before and once after using them. Both had invented fake sneezes, which they deployed strategically—as “jokes”—to diffuse tense moments of conversation. Both had violent, explosive tempers and unexpected spasms of anxiety. A pair of twins had an identical manner of rubbing their noses, and— even though they had never met—had each invented a new word to describe the odd habit: squidging. Two sisters in Bouchard’s study shared the same pattern of anxiety and despair. As teenagers, they confessed, they had been haunted by the same nightmare: of feeling suffocated in the middle of the night because their throats were being stuffed with various—but typically metallic—things: “door-knobs, needles and fishhooks.”
Source :
1) https://www.nationalgeographic.com/magazine/2012/01/identical-twins-science-dna-portraits/#:~:text=Because%20identical%20twins%20come%20from,time%20spent%20in%20the%20sun.
2) https://www.amazon.in/dp/B06XY1PDMV/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1
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