THE RED QUEEN

Sex and The Evolution of Human Nature

Matt Ridley, 1993, Penguin Books

Created: April 6th, 2003 Sunday 15:12, Ankara

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The Red Queen is about the evolution of sex in humans. Very interesting indeed. Notes that I took while reading:

• "Only 7 percent of the genetic differences between two individuals can be attributed to the fact that they are of different race; 85 percent of the genetic differences are attirbutable to mere individual variation, and the rest is tribal or national. ... the average difference between one Peruvian farmer and his neighbor, or one Swiss villager and his neighbor, is twelve times greater than between the 'average genotype' of the Swiss population and the 'average genotype' of the Peruvian population." (p.13)
• "Selection within the species is always going to be more important than selection between the species. ... the closest competitor a creature is ever likely to meet is a member of its own species." (p.34)
• "Even in the most spectacular cases of selflessness it turns out that animals are serving the selfish interests of their own genes-if sometimes being careless with their bodies." (p.35)
• "...no creature could ever evolve the ability to help its species at the expense of itself. Only when the two interests coincided would it act selflessly. ... The traditional explanation for sexi the Vicar of Bray theory, was essentially group selectionist. It demanded that an individual altruistically share its genes with those of another individual when breeding because if it did not, the species would not innovate and would, a few hundred thousand years later, be outcompeted by other species that did. Sexual species, it said, were better off than asexual species. But were sexual individuals better off than asexual ones?" (p.36)
• "How could a gene for sexual reproduction spread at the expense of an asexual gene? Suppose all members of a species were asexual but one day one pair of them invented sex. What benefit would it bring? And if brought no benefit, why would it spread? And if it could not spread, why were so many species sexual? Ghiselin could not see how the new sexual individuals could possibly leave behind more offspring than the old asexual ones. Indeed, surely they would leave fewer because, unlike their rivals, they had to waste time finding each other, and one of them, the male, would not produce babies at all." (p.37)
• "So we are left with an enigma. Sex serves the species but at the expense of the individual. Individuals could abandon sex and rapidly outcompete their sexual rivals. But they do not. Sex must therefore in some mysterious manner "pay its way" for the individuals as well as the species. ... two parthogenic virgins can have twice as many babies as one woman and one man." (p.40)
• "The most obvious reason to borrow genes is to benefit from the ingenuity of others as well as yourself. ... this argument confuses consequence with cause. Its advantages are far too remote; they will appear after a few generations, by which time any asexual competitor will long ago have outpopulated its sexual rivals. Besides, if sex is good at throwing together good combinations of genes, it will even be better at breaking them up." (p.46)
• "...the random loss fo certain lines of descent will mean that the average number of defects gradually increases." (p.48)
• "...if your young are going to travel abroad, then it is better that they vary because abroad may not be like home." (p.56)
• "Breeding asexually is like having lots of lottery tickets all with the same number. To stand a chance of winning the lottery, you need lots of different tickets." (p.57)
• "...it does not matter that your young are good enough to survive. What matters is whether they are the very best. Sex gives variety, so sex makes a few of your offspring exceptional and a few abysmal, whereas asex makes them all average. ... these lottery models only work if the prize that rewards the right lottery ticket is indeed a huge jackpot." (p.58)
• "Lottery models predict that sex should be most common where in fact it is rarest - among highly fecund, small creatures in changeable environments. On the contrary, here sex is the exception; but in big, long-lived, slow breeding creatures in stable environments sex is the rule." (p.59)
• "In a saturated economy, it pays to diversify." (p.60)
• "The trouble is, all these results are also predicted by rival theories just as plausibly. ... the fallacy of affirming the consequent." (p.61)
• "...species do not change much. They stay exactly the same for thousands of generations, to be suddenly replaced by other forms of life. The tangled bank is a gradualist idea. ... A gradual drifting away of a species from its previous form happens on small islands or in tiny populations precisely because of effects somewhat analogous to Muller's ratchet: the chance extinciton of some forms and the chance prosperity of other, mutated forms." (p.62)
• "...it is stasis, not change that is the hallmark of evolution. ... there is no evidence yet found that any creature ever does anything other than try to keep its mutation rate as low as possible. It strives for a mutation rate of zero. Evolution depends on the fact that it fails." (p.63)
• "The struggle for existence never gets easier. However well the species may adapt to its environment, it can never relax, because its competitors and its enemies are also adapting to their niches. Survival is a zero sum game." (p.64)
• "There may be more bacterial than human cells in the object you proudly call "your" body. ... Human beings have no predators except great white sharks and one another, but they have lots of parasites." (p.66)
• "Parasites provide exactly the incentive to change genes every generation that sex seems to demand." (p.67)
• ...one ingenious theory holds that sperm are small specifically so that they have no room to carry bacteria with them to infect eggs." (p.70)
• "The longer your generation time, the more genetic mixing you need to combat your parasites." (p.71)
• "So why on earth are stuffed with so many different versions of genes?" (p.72)
• "In a case where rarity is premium, the advantage is always swinging from one gene to another, and no gene is ever allowed to become extinct." (p.73)
• "The immune system consists of white blood cells that come in about 10 million different types. Each type has a protein lock on it called an "antibofy", which corresponds to a key carried by a bacterium called "antigen". If a key enters that lock, the white cell starts multiplying ferociously...But the body can not keep armies of each antibody-lock...So it keeps only a few copies of each white cell." (p.74)
• "Each lock is generated by a sort of random assembly device that tries to maintain as broad library of  kinds of locks as it can, even if some of the keys that fit them have not yet been found in parasites. This is because parasites are continually changing their keys to try to find ones that fit the host's changing locks. The immune system is therefore prepared. But this randomness means that the host is bound to produce white cells that are designed to attack its own cells among the many types it invents. To get around this, the host's own cells are equipped with a password, which is known as major histocompatibility antigen. This stops the attack. To win, then, the parasite must do one of the following: infect somebody else by the time the immune reponse hits (as flu does), conceal itself inside host cells (as the AIDS virus does), change its own keys frequently (as malaria does), or try to immitate whatever password the host's own cells carry that enable them to escape attention. ... The AIDS virus is the craftiest of all. According to one theory, it seems to keep mutating so that each generation has different keys. Time after time the host has locks that fit the keys and the virus gets suppressed. But eventually, after perhaps ten years, the virus's random mutation hits upon a key that the host does not have a lock for. At that point the virus has won. ... In essence, according to this theory, the AIDS virus evolves until it finds a chink in the body's immune armor." (p.75)
• "Disease might almost put a sort of limit on longevity: There is little point in living much longer than it takes your parasites to adopt to you. How yew trees, bristlecone pines, and giant sequoias get away with living for thousands of years is not clear, but what is clear is that, by virtue of chemicals in their bark and wood, they are remarkably resistant to decay." (p.80)
• "...sex is no good if there is no genetic variety: It's no good changing the locks if there is only one type of lock available." (p.83)
• "...at first sight, the most foolish system of all [sexual reproduction] is two sexes because it means that fully 50 percent of the people you meet are incompatible as breeding partners. If we were hermaphrodites, everybody would be a potential partner." (p.87)
• "Individual rational behavior leads to a collectively irrational outcome. The free-rider wins at the expense of the good citizen." (p.91)
• "When a sperm fertilizes an egg, it donates just one thing to that egg: a bagful of genes called a nucleus. The rest of it stays outside the egg. A few of the father's genes are left behind because they are not in the nucleus at all; they are in little structures called "organelles". There are two main kinds of organelles, mitochondria, whih use oxygen to extraxt energy from food, and chloroplasts (in plants)... Evolution seems to have gone extraordinary lengths to keep the father's organelles out." (p.100)
• "If your host is going to die, you had better multiply as fast as possible." (p.103)
• "If it pays a parasite to go broke when a rival appears, then it pays the host to prevent cross-infection with two strains of parasite. And nowhere is the risk of cross-infection greater than during sex. A sperm fusing with an egg risks bringing its cargo of bacteria and viruses as well; their arrival would awaken the egg's own parasites and cause battle for posession that would leave the egg sick or dead. To avoid this, therefore, the sperm tries to avoid bringing into the egg material that might harbor bacteria or viruses. It passes just the nucleus into the egg. Safe sex indeed. [this looks like a reason for having genders]." (p.104)
• "But it does not explain why every creature cannot have both genders on board." (p.105)
• "The sex chromosomes themselves began to have an interest in the gender of their owner's children. In a man, for instance, the genes that control gender are on the Y chromosome. Half of a man's sperm are X carriers and half are Y carriers. To father a daughter, the man must fertilize hiz mate with an X carrier. In doing so he passes none of the Y genes to her. From the Y's point of view, his daughter is unrelated to him. Therefore, a Y gene that causes the death of all the man's X-bearing sperm and ensures its own monopoly of the man's children will thrive at the expense of all other kinds of Y genese. That all those children are sons and the species will therefore go extinct matters not in the least to the Y; he has no foresight. ... what prevented it from happening..." (p.110)
• "Far from settling down to a fair and reasonable way of determining gender, nature has to face an infinite series of rebellions." (p.111)
• "...a cometition to have the most grandchildren." (p.115)
• "High rank leads to a sex bias in favor of the gender that does not leave at puberty." (p.118)
• "...a hen is just an egg's way of making another egg." (p.131)
• "In species where the females get nothing useful from their mates, they seem to choose on aesthetic citeria alone." (p.134)
• "...we are designed for a system of monogamy palgued by adultery." (p.176)
• "It is not how often a male bird copulates that determines the size of his testicles but how many other males he competes with." (p.222)
• "Men and women have different minds." (p.248)
• "Sex-blind education may be unfair education." (p.249)
• "There is no evidence of genes for different brains, but there is ample of evidence of genes for altering brains in response to male hormones." (p.254)
• "...man has instincts to learn things." (p.316)
• "...big brains do not come free. In human beings, 18 percent of the energy that we consume everday is spent in running the brain." (p.326)
• "Mankind is not the learning ape, he is the clever ape with more instincts and more open to experience. ... Why is intelligence a good thing?" (p.329)
• "...Homo erectus did not need consciousness to know that you should stalk zebras upwind every time lest they scent you ... the key feature of the human environment that rewarded intelligence was the presence of other human beings." (p.330)
• "We are obsessed with one another's minds." (p.333)
• "The neocortex is largely a courtship device to attract and retain sexual mates: Its specific evolutionary function is to stimulate and entertain other people, and to assess the stimulation attempts of others." (p.338)
• "I sometimes feel that we are fated never to understand ourselves because part of our nature is to turn every inquiry into an expression of our own nature: ambitious, illogical, manipulative, and religious. ... But as long as we can keep asking why, we have a noble purpose." (p.349)

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