He applied the “Page 99 Test” to his new book, Mate Choice: The Evolution of Sexual Decision Making from Microbes to Humans, and reported the following:
An important personal reason for writing this book was that I felt blinkered by focusing so much on my own experimental work on swordtail fish. It was both humbling and richly fulfilling to learn so much about what other people were doing using different experimental systems and theoretical approaches. I was therefore bemused to turn to page 99 and find it all devoted to the story of how people including myself have thought about mate preferences in swordtails over the past thirty years.Learn more about Mate Choice at the Princeton University Press website.
On the other hand, I purposefully used the swordtail narrative as a microcosm of the major themes I try to develop in the book. We started off thinking about the crudest possible preference rule – more is better. The scenario that we proposed was that females – implicitly, all females, all the time – preferred males conferring more gross visual stimulation – males that looked bigger. This bigger-is-better bias was ancient and hadn’t changed much for millions of years, since before there were even swordtails around.
The picture we have now of preferences, in swordtails as in other animals from stalk-eyed flies to Bengalese finches, is a vastly richer one, in which genes, environment, and culture interact to shape a rick diversity of desires and choices - among species, from one individual to the next, and even within the same individual at different times and in different contexts. Page 99 is in the introduction to chapter 4, where our understanding of preference mechanisms moves beyond low-level sensory responses and towards the sophisticated integration of complex stimuli using different senses. I go on to describe mate choice as an intricate process, where one’s genetic makeup and experiences can favor different partners before, during, and after mating. The rest of the book uses an understanding of these mechanisms to inform a view of how mate choice arises and evolves, and in turn how mate choice can both build up and erode genetic barriers between species. Finally, I suggest that work on mate-choice evolution in humans might more fruitfully consider the diversity and complexity of sexual choices in our own species.
--Marshal Zeringue