All this is very logical, but in about 1990 it started to make one group of biologists uneasy. They had an instinctive aversion to the idea that sexual advertising is about the truth because they knew that television advertising is not about passing on information; it is about manipulating the viewer. In the same way, they argued, all animal communication is about manipulating the receiver.
The first and most eloquent (manipulative?) champions of this view were two Oxford biologists, Richard Dawkins and John Krebs: According to them, a nightingale does not sing to inform potential mates about himself; he sings to seduce them. If that means lying about his true prowess, so be it: 62 Perhaps an ice cream advertisement is honest in a simplistic sense because it gives the name of the brand, but it is not honest in implying that sex is sure to follow after every spoonful. Such a crude lie can surely be perceived by that genius of the animal kingdom, humans. But it is not.
Advertising works. Brand names are better known if they are advertised with sexy or alluring pictures, and better-known brands sell better. Why does it work? Because the price the consumer would have to pay in ignoring the subliminal message is just too high. It is better to be fooled into buying the second-best ice cream than go to the bother of educating yourself to resist the salesmanship.
Any peahens reading this might begin to recognize their dilemma. For they, too, may be fooled by the male's display into buying the second-best male: Remember, the lek paradox argues that there is little to choose between males on a lek anyway because they were all fathered by the same few males in the previous genera-THE PEACOCKS TALE
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tion. So two theories—truth in advertising and dishonest manipulation—seem to come to opposite conclusions. Truth in advertising concludes that females will discover a cheating seducer; dishonest manipulation concludes that males will seduce females against their better judgment.
WHY DO YOUNG WOMEN HAVE NARROW WAISTS?
Marian Dawkins and Tim Guilford of Oxford have recently suggested a resolution to this conundrum. As long as detecting the dishonesty in the signal is costly to the female, it might not be worth her while to do so. In other words, if she has to risk her life seeking out and comparing many males to ensure that she has chosen the best one, then the marginal advantage she gains by picking the best one is outweighed by the risk she has run. It is better to let herself be seduced by a good one than to have the best become the enemy of the good. After all, if she cannot easily distinguish the truthful from the dishonest badge of quality, then other females will not, either, and so her sons will not be punished for any dishonesty they inherit from their father."
A startling example of this sort of logic comes from a controversial theory about human beings that was developed a few years ago by Bobbi Low and her colleagues at dhe University of Michigan: Low was looking to explain why young women have fat on their breasts and buttocks more than on other parts of their bodies. The reason this requires explaining is that young women are different from other human beings in this respect. Older women, young girls, and men of all ages gain fat on their torsos and limbs much more evenly. If a woman of twenty or so gains weight, it largely takes the form of fat on the breasts and buttocks; her waist can remain remarkably nartow.
So much is undisputed fact. What follows is entirely conjecture, and it was a conjecture that caused Low a good deal of sometimes vicious (and mostly foolish) criticism when she published the idea in 1987:
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The Red Queen
Twenty-year-old women are in their breeding prime; therefore, the unusual pattern of fat distribution might be expected to be connected with getting a mate or bearing children. Standard explanations concern the bearing of children; for example, fat is inconvenient if it competes for space about the waist with a fetus.
Low 's explanation concerns the attraction of mates and takes the form of a Red Queen race between males and females. A man looking for a wife is likely to be descended from men who found two things attractive (among many others): big breasts, for feeding his children, and wide hips, for bearing them. Death during infancy due to a mother 's milk shortage would have been common before modern affluence—and still is in some parts of the world. Death of the mother and infant from a birth canal that was too narrow must also have been common. Birth complications are peculiarly frequent in humans for the obvious reason that the head size of a baby at birth has been increasing quickly in the past 5 million years. The only way birth canals kept pace (before Julius Caesar 's mother was cut open) was through the selective death of narrow-hipped women.
Grant, then, that early men may have preferred women with relatively wide hips and large breasts. That still does not explain the gaining of fat on breasts and hips; fat breasts do not produce more milk than lean ones, and fat hips are no farther apart than lean ones of the same bone structure. Low thinks women who gained fat in those places may have deceived men into thinking they had milkful breasts and wide hip bones: Men fell for it—
because the cost of distinguishing fat from heavy breasts or of distinguishing fat from wide hips was just too great, and the opportunity to do so was lacking. Men have counterattacked, evolutionarily speaking, by "demanding" small waists as proof of the fact that there is little subcutaneous fat, but women have easily overcome this by keeping waists slim even while gaining fat elsewhere."
Low ' s theory might not be right, as she is the first to admit, but it is no less logical or farfetched than any of its rivals, and for our purposes it serves to demonstrate that a Red Queen race between a dishonest advertiser (in this case, unusually, a THE PEACOCKS TALE
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female) and a receiver who demands honesty may not always be won by the honesty-demanding gender. It is essential, if Low is right, that fat be cheaper to gain than mammary tissue, just as it is essential, for Dawkins and Guilford, that cheating be cheaper than telling the truth."
CHUCKING FROGS
The male 's goal is seduction: He is trying to manipulate the female into falling for his charms, to get inside her head and steer her mind his way: The evolutionary pressure is on him to perfect displays that make her well disposed toward him and sexually aroused so that he can be certain of mating: Male scorpions lull females into the mood for sex at great risk to their lives. One false step in the seduction, and the female 's mood changes so that she looks upon the male as a meal.
The evolutionary pressure on a female—assuming she benefits from choosing the best male—is to invent resistance to all but the most charming displays: To say this is merely to rephrase the whole argument of female choice with a greater emphasis on the how than the why. But such rephrasings can be illuminating, and this one has proved exceptionally so. Michael Ryan of the University of Texas rephrased the question a few years ago, and he did so partly because he studies frogs: It is easy to measure female preferences in frogs because the male sits in one spot and calls, and the female moves toward the sound of the male she likes the most: Ryan replaced the males with loudspeakers and offered each female different recordings of males to test her preference.
The male tungara frog attracts a female by making a long whine followed by a "chuck " noise. All of its close relatives except one make the whine but not the chuck: But at least one of the chuckless relatives turns out to prefer calls with chucks to those without. This was rather like discovering that a New Guinea tribesman found women in white wedding dresses more attractive than women dressed in tribal gear. It seems to indicate that the