Biology

Books

The Autobiography of Charles Darwin | Nora Barlow


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Published in: 1993

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When Charles Darwin wrote his memoirs, he was 67 years old and lived a secluded life in his home, where he observed the outraged debate that his theories gave rise to. During his lifetime he had written some of the most important books in history, where mainly On the Origin of Species and The Desccent of Man sent shock waves through churches and universities. His autobiography was published in 1887, five years after his death.

THE DOCTOR’S SON. Charles Darwin was born in Shrewsbury on 12 February 1809. His mother died when he was eight years old, and his father was a medical doctor and a careful businessman. The father was not very scientifically inclined but acted as moral support. Darwin’s grandfather, however, had written the Botanic Garden and other works. Charles Darwin’s interest in natural history, especially in collecting, started in his early school years.

SCHOOL – A TORMENT. Darwin regarded primary school as an institution, and he had difficulty learning languages (which was considered particularly important). However, from an early age he had felt a strong desire to understand or explain everything he had observed, and to bring all the facts together under a universal law. In 1825, Darwin, like his brother, began studying medicine at the University of Edinburgh. But the lecture-based teaching was unbearably boring. He was by then told that his father would leave behind a fortune large enough to live well on. It was enough to not make an effort in the medical studies. After two years of study in Edinburgh, Cambridge followed.

MENTOR HENSLOW. From a study point of view, the three years at Cambridge were as wasted as the years at Edinburgh. He tried to understand mathematics, but it went slowly. In Cambridge, however, he became friends with Professor Henslow – a man with extensive knowledge in botany, entomology, chemistry, mineralogy, and geology. It was Henslow who said that Captain Fitz-Roy was willing to take an unpaid natural scientist on the journey with “The Beagle”. Darwin’s father first opposed this idea but said: “if you can find a wise and sensible man who advises you to travel, I give my consent”.

THE LEGENDARY ”BEAGLE”. Beagle sailed from Plymouth in December 1831. While the expedition was originally planned to last for two years, it lasted almost five, and Beagle did not return until October 1836. Darwin spent most of this time exploring on land (39 months on land; 18 months at sea).

RETURNING HOME. In March 1837, Darwin rented an apartment in London where he completed his diary for two years, lectured at the Geological Society, began the manuscript of the Geological Observations on South America (published in 1846) and edited the book Zoology of the Voyage of the Beagle. In the summer of 1837 he began, without setting up a theory, to compile facts for On the Origin of Species, which he worked on for the next twenty years. When he looks back at the books and writings he read and summarized, he is amazed at his diligence.

“In October 1838 … I happened to read for amusement Malthus on Population … it at once struck me that under these circumstances favorable variations would tend to be preserved, and unfavorable ones to be destroyed. The result of this would be the formation of new species.”

A 20 YEAR PROJECT. After Darwin read Malthus, he finally had a theory to work on. Darwin began working on the subject in 1837. In 1842 he had drawn “some short notes” of five pages, and in 1844 expanded them to a sketch of 230 pages. In early 1856, Darwin wrote down the theory in detail, and this material became three to four times more comprehensive, albeit only a summary of the material collected, than what was published in 1859 in On the Origin of Species. Darwin says that he gained a lot from waiting with the publication from 1839, when the theory was clearly formulated, until 1859. The timing contributed to the theory being well received.

SELF-REFLECTION. Darwin did not consider himself to have the quick perception or wit of many other intelligent scientists (he was therefore a bad critic; “when I read an essay or book for the first time, it usually arouses my admiration, and it is only after a lot of thought that I detect the weak points.”). His ability was limited to, for example, follow a long and completely abstract reasoning used in metaphysics or higher mathematics. Some critics said, “of course he is a good observer, but he has no ability to reason.” However, Darwin did not agree with this. Origin of Species is a single long reasoning and has convinced many knowledgeable men.

PATIENCE AND PERSEVERANCE. Darwin describes himself as quite inventive and has a lot of common sense and good judgment (“as a reasonably successful lawyer or doctor but no more than that”). Darwin judged that he was better than people in general at noticing, and carefully observing, things that others easily overlooked. His diligence when it came to observing and gathering facts as well as love of science could not have been greater. This gave him such patience that he was able to reflect or ponder unresolved problems for many years. He always tried to keep his mind free so that he could abandon any hypothesis if it turned out to contradict the facts.

Books

The Real Happy Pill | Anders Hansen


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Published in: 2016

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Imagine traveling back to 10,000 years B.C. The people you meet would speak a different language and have completely different experiences. But by and large, they would be like you. We humans, including our brains, have not changed much in 12,000 years. But our lifestyle has changed tremendously in just 100 years, even more in 12,000 years. For millions of years, our ancestors had to be on the move to obtain food and survive. The result is that we not only have a body that is built for movement, but also a brain that is. This is a book about exercise and how we have walked out of step with our biology – or rather: we sit out of step with it.

BIOLOGICAL MISMATCH. If you look at the history of mankind as a day, we were hunters and gatherers until 23:40. We became industrialized at 23:59:40 (20 seconds before twelve o’clock) and digitized, connected to the internet, 23:59:59 (one second before twelve o’clock).

NATURE VS NURTURE. Your DNA alone does not determine how your brain will develop. You have about 23,000 genes. And you have 100 billion brain cells that have about 100,000 billion connections between each other. 23,000 genes cannot determine all of these links. The brain is too complex to be completely controlled by a genetic program where it is predetermined how it will develop. The genes set a framework for how brain cells are formed and die, connect to each other and break connections. Exactly how this happens, what qualities you develop and how you function, is affected by what you been through, what environment you live in and what lifestyle you choose.

THE HPA AXIS. The body has a stress system called the HPA axis. When the brain detects something it perceives as a threat, the Hypothalamus (“H” in HPA) sends a signal to a gland in the brain, the Pituitary (“P” in HPA), which responds by releasing a hormone that travels into the bloodstream with your Adrenal glands (“A” in HPA), that responds by releasing the stress hormone cortisol which makes the heart beat faster and harder. The motor of the HPA axis is the amygdala, which is the brain’s alarm system. The amygdala activates the stress system, but can also be triggered by it. When the amygdala signals danger this leads to increased cortisol levels, which makes the amygdala even more active and increases cortisol levels even more. If the amygdala is allowed to unwind uncontrollably, you will eventually panic.

AMYGDALA ACCELERATES, HIPPOCAMPUS BRAKES. To slow down the stress system, the body and brain have several brake pedals built in. One of these is located in the memory center hippocampus, which has an ability to slow down the stress system and act as a counterweight to the stress motor amygdala. There is always a balance where they pull in different directions. When the hippocampus can no longer slow down the amygdala, the stress system begins to live its own life. Another stress brake is the frontal lobe / prefrontal cortex, a seat of “higher thinking”, which has a central role in not overreacting emotionally and acting irrationally. Here, too, a balance is created with the amygdala.

CORTISOL LEVELS MUST DECREASE. It is natural that cortisol levels increase from stress. But it is important that they decrease when the stressful situation is over. The stress hormone cortisol is almost a poison to the brain cells in the hippocampus (which can die from too much cortisol), and if there is too much for a long time (rather months and years rather than hours and days) the hippocampus risks shrinking slightly. This can make the memory worse.

EXERCISE AS MEDICINE. Exercise means stress for the body. Cortisol levels increase while running, cycling or other physical activity. But after the workout, the body does not need the same stress boost. Then cortisol levels drop to lower levels than before. If you continue to exercise regularly, cortisol will gradually increase less and less each time, and decrease more afterwards. It will also increase less and less even when you are stressed for other reasons. In fact, the frontal lobe and the hippocampus are the two parts of the brain that are most strengthened by your movement. But it is important to make exercise a habit – it takes time before the hippocampus and frontal lobe are strengthened.

GABA – ACTIVATED BY EXERCISE. GABA (Gamma-aminobutyric acid) is a substance whose function is to calm the brain and dampen the activity of brain cells (when the activity is calmed, the feelings of stress disappear). GABA activation means fast and effective stress relief – just like when you drink alcohol or take sedatives. GABA is also activated by movement. You get some effect if you walk, but the best thing is to run or cycle.

EXERCISE ATTACKS STREES FROM SEVERAL ANGLES.  Stress reduces the brain’s ability to change (plasticity) while exercise increases it. Increased stress slows down the transition from short-term to long-term memories while exercise improves it. The really nice effects on well-being and stress resistance are only noticeable after a couple of months of regular training. Exercise attacks stress and anxiety from several angles. Cortisol levels drop after a workout and will not rise as sharply next time. The “brake pedals” hippocampus and frontal lobe are strengthened and become better at breaking the anxiety motor amygdala. The activity of the brain’s braking system GABA increases and the muscles’ ability to neutralize a stress substance increases. All this is happening at the same time.

EXERCISE

EXERCISE – A DOSE AGAINST STRESS AND ANXIETY. Most indications are that cardio training provides more from a stress perspective than strength training. Be active for at least 20 minutes, preferably 30-45 minutes. Make sure to get your heart rate up at least 2-3 times a week. Exercise intensily once a week, for example with interval training (has an extra good effect against anxiety).

EXERCISE – A DOSE FOR BETTER CONCENTRATION. Run instead of walk. If you move more intensely, the brain releases more dopamine and norepinephrine. You should reach 70-75% of your maximum heart rate. For concentration, it is usually better to exercise in the morning so that the effect can last during the day. You should be active for at least 20 minutes, but preferably 30 minutes to get a good effect.

THE EXERCISE – A DOSE TO FEEL BETTER. Run three times a week for 30-45 minutes each time. The intensity should be at least 70 percent of your maximum capacity. Cycling or other cardio training is as good as running. Keep this for at least six weeks.

EXERCISE – A DOSE FOR BETTER MEMORY. For memory, a walk of 30 of minutes is enough – it’s probably better than running for several hours. It is best to vary between cardio and strength training. The effects of cardio training on the hippocampus are what have been studied the most, but there seem to be effects on memory that you only, or mainly, get from strength training. Do not exert yourself too intensely, a walk or a lighter run is enough. You get the greatest effect on memory the day or days after training. Exercise regularly for several months straight.

THE TRAINING – A DOSE THAT INCREASES CREATIVITY. The best thing is to run, but also to walk has an effect. Run for at least 20-30 minutes. The effect on creativity comes afterwards and lasts for about 2 hours. Do not take yourself out completely, then creativity will be worse for several hours after training (but not in the long run). The training improves the ability to brainstorm, above all, but it can differ from person to person.

”The moment my legs begin to move, my thoughts begin to flow” – Henry David Thoreau

Books

The Selfish Gene | Richard Dawkins


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Published in: 1976 / 2009

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The selfish gene theory is Darwin’s theory. But rather than focus on the individual organism, this book takes a gene’s-eye view of nature. And if you look at the way natural selection works, it seems to follow that anything that has evolved by natural selection should be selfish while we must teach generosity and altruism. This book will show how both individual selfishness and individual altruism are explained by the fundamental law called “gene selfishness”.    

THE BEGINNING. At some point a remarkable molecule was formed by accident. We call it the Replicator. It had extraordinary property of being able to create copies of itself (think of it as a mold or template). The copying process was not perfect, and mistakes happened. But erratic copying can give rise to improvement, and it was errors essential for the progressive evolution of life. DNA-molecules are modern equivalents of the first replicators.

SURVIVAL OF THE STABLE. Certain molecules, once formed, would be less likely than others to break up again. The universe is populated by stable things. A stable thing is a collection of atoms that is permanent enough or common enough. All material things – rocks, galaxies, ocean waves – are, to a greater or lesser extent, stable patterns of atoms.

COMPETITION – A NATURAL STATE. If replicator molecules of type A make copies of themselves on average once a week and type B once an hour, soon type A will be far outnumbered even if they “live” much longer. If molecules of type X and type Y last the same length of time and replicate at the same rate, but X makes a mistake on average every tenth replication while Y makes a mistake only every hundredth replication, Y will be more numerous. Any mis-copying that resulted in a new higher level of stability, or reducing the stability of rivals, was automatically preserved and multiplied. This process was cumulative. When replicators became numerous, building blocks must have been used up at such a rate that they became a scarce resource. Different replicators must have competed for them. 

SURVIVAL MACHINES IS CREATED. Replicators discovered how to protect themselves, either chemically, or by building a wall of protein around themselves (this may have been how the first living cells appeared). Replicators began to construct vehicles for their continued existence, and those that survived were the ones that built “survival machines” to live in. Survival machines got bigger and more elaborate, and the process was cumulative and progressive. They created us, the body and the mind, and their preservation is the ultimate rationale for our existence. They have come a long way, those replicators. Now they go by the name of genes, and we are their survival machines.

CLUSTERS OF GENES. All people, animals, plants, bacteria, and viruses are survival machines (for the replicator DNA). But survival machines are not just carrying one gene but many thousands. Any one chromosome in a sperm would be a patchwork of maternal genes and paternal genes. A body is a cooperative venture of such intricacy that it is almost impossible to disentangle the contribution of one gene from another. Some genes act as master genes controlling the operation of a cluster of genes. The combination of genes that is in any one individual may be short-lived, but the genes are potentially very long-lived. Their paths constantly cross and recross down the generations. The genes are not destroyed by crossing-over, they merely change partners. They are the replicators, and we are their survival machines.

A COMPLEX SURVIVAL GAME. A gene can live for a million years, but, many new genes do not even make it past their first generation. The few ones that succeed do so partly because they are lucky, but mainly because they have what it takes, and that means they are good at making survival machines. Genes are competing directly with their allies for survival, since their allies in the gene pool are rivals for their slots on the chromosomes of future generations. Any gene that behaves in such an expense of its allies will, by definition, tautologously, tend to survive.  

THE GENE MACHINE. Neurons are basically just cells, with a nucleus and chromosomes like other cells. But their cell walls are drawn out in long, thin, wire-like projections. The main way in which the brain actually contribute to the success of survival machines is by controlling and coordinating the contractions of muscles. Natural selection favored animals that became equipped with sense organs, devices which translate patterns of physical events in the outside world into the pulse code of the neurons.

DECISION-MAKING. Every decision that a survival machine takes is a gamble. It is the business of genes to program brains in advance so that on average they take decisions that pay off. The currency used in the casino of evolution is gene survival but for many purposes individual survival is a reasonable approximation. One way for genes to make predictions in unpredictable environments is to build in a capacity for learning. The program may take the form of instructions to the survival machine, such as rewarding (sweet taste, orgasm, mild temperature, smiling child), nasty (pain, nausea, empty stomach, screaming child). This programming greatly cuts down the number of detailed rules that have to be built into the original program, and is capable of coping with changes in the environment.

SIMULATION. No simulation can predict exactly what will happen. But a good simulation is preferable to blind trial-and-error. You imagine what would happen if you did each of the alternatives open to you. You set up a model in your head of the restricted set of entities which you think may be relevant that will be used to predict possible events. Survival machines that can simulate the future are one jump ahead of survival machines that can only learn on overt trial and error. Trial-and-error takes time and energy and is often fatal. Simulation is both safer and faster. The evolution of the capacity to simulate seems to have culminated in subjective consciousness.

OUTSOURCING RESPONSIBILITIES. Genes are the primary policy-makers, brains are the executives. But as brains became more developed, it took over more and more of the actual policy decisions, using tricks like learning and simulation. The logical conclusion to this trend, not yet reached in many species, would be for the genes to give the survival machine a single overall policy instruction: do whatever you think best to keep us alive.

EVOLUTIONARY STABLE SYSTEMS. A strategy is a pre-programmed behavioral policy. An example of a strategy is: “Attack opponent, if he flees pursue him, if he retaliates run away”. An evolutionary stabile strategy or ESS is a strategy which in most members of a population adopt it cannot be bettered by an alternative strategy. The best strategy for an individual depends on what most of the population is doing. Since the rest of the population consists of individuals, each one trying to maximize his own success, the only strategy that persists will be the one which, once evolved, cannot be bettered by any deviant individual. Following a major environmental change there may be a brief period of evolutionary instability. But once an ESS is achieved it will stay: selection will penalize deviation from it.

HUMAN ESS. The trouble with conspiracies, even those that are to everybody’s advantage in the long run, is that they are open to abuse. The conspiracy is often bound to be broken by treachery from within. An ESS is stable, not because it is particularly good for the individuals participating in it, but because it is immune to treachery from within. It is possible for humans to enter into pacts or conspiracies that are to every individual’s advantage, even if these are not stable in the ESS sense. But this is only because every individual uses conscious foresight and is able to see that it is in his own long-term interest to obey the rules of the pact.

TIT-TOR-DOUBLE TAT. A winning strategy is tit-for-tat which begins by cooperating on the first move and thereafter copies the previous move of the other player. Tit for two tats allows its opponent two defections in a row before it eventually retaliates. This might seem excessively saint, but it has won game theory tournaments. This is because it avoids runs of mutual recrimination. There are two characteristics of winning strategies: niceness and forgiveness. Tit-for-tat seems as an ESS, but it is in the stricter sense not so. To be an ESS, a strategy must not be invadable by a rare mutant strategy. Tit-for-tat cannot be invaded by any nasty strategy but another nice strategy.

MEMES: THE NEW REPLICATORS. Memes are the culture equivalent of genes, i.e. replicators. Examples of memes are tunes, ideas, catch-phrases, clothes fashion, ways of making pots or of building arches. Just as genes propagate themselves in the gene pool by leaping from body to body, so memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation. If a scientist hears, or reads about, a good idea, he passes it on to his colleagues and students. It spreads from brain to brain. Imitation, in the broad sense, is how memes can replicate. But just as not all genes that can replicate do so successfully, so some memes are more successful in the meme-pool than others. This is the analogue of natural selection. Some memes, like some genes, achieve brilliant short-term success in spreading rapidly, but do not last in the meme pool.  

Documentaries

Three Identical Strangers


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In 1980 New York, three young men who were all adopted meet each other and find out they’re triplets who were separated at birth. But their quest to find out why turns into a bizarre and sinister mystery.

Books

Inheritance | Sharon Moalem


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In 1975, Arthur Riggs and Robin Holliday came, almost simultaneously, but from different angles, to the conclusion that even if genes were fixed, they could give different expressions in response to stimuli. It took another 25 years before these ideas gained wider acceptance. Researchers are now beginning to understand what our genes do to us and what we do to our genes. Conditions can be hidden and identical genes in different people do not always have to behave in an identical way despite the exact same set of DNA. The idea of flexible inheritance teaches us that it is possible to accept and reject our heritage. The concept of variable genetic expressivity is about how someone is affected by a genetic mutation or condition.

A Brief of the book can be read here

Documentaries

Human Nature


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The revolutionary genetic scissors CRISPR has given scientists control over the building blocks of life. By changing DNA, technology provides unimaginable opportunities to cure diseases, reshape animals and vegetation, and to design our own children. Researchers, families and engineers talk about the fascination with the potential of genetic scissors, but also about the concern about what CRISPR can be used for. A film by Adam Bolt.

The documentary can be seen at Netflix or purchased at iTunes