Vellend applied the “Page 99 Test” to his new book, Everything Evolves: Why Evolution Explains More than We Think, from Proteins to Politics, and shared the following:
On page 99 of my book, Everything Evolves: Why Evolution Explains More than We Think, from Proteins to Politics, there are two figures. The only text on the page is in the figure captions. The two figures contain graphs that illustrate different forms of evolutionary selection. In the simplest scenario (Figure 5.1), one type of entity (e.g., an iPhone or the Omicron variant of the virus causing Covid-19) has higher fitness than another (e.g., a BlackBerry or the Delta variant) because of some characteristic: the ease of internet access for cell phones and the ease of transmission for viruses. The second set of graphs (Figure 5.2) shows more generalized forms of selection. Directional selection is illustrated by the evolution of the shape of violin sound holes, which gradually changed from semi-circular to the now-familiar cursive f-shape shape, based on improved sound volume and quality. “Balancing selection” is when evolutionary fitness is greatest for intermediate trait values, in this case the size of cell phones: medium sized ones are more successful than tiny ones or very large ones. “Divergent selection” – maximum fitness of extreme trait values – is illustrated by bird beaks, which might be favored when small or large (if the seeds the birds eat are small or large) but not in between.Visit Mark Vellend's website.
On the Page 99 Test, I would say that Everything Evolves gets a grade of C. If a reader opened the book to page 99, they would get a reasonably clear sense of one key argument in the book: Evolutionary processes – in this case selection – apply equally to cultural or technological change (cell phones, violins) as they do to biological change (viruses, birds). That said, gleaning this message would be difficult without some background in evolutionary science (provided in the book), and there is no indication of other evolutionary processes (variation generation, drift, movement), or of the arguments as to why generalized evolutionary science is important and historically underappreciated. So, on page 99 alone a reader would get some sense of one key aspect of the whole work, but little sense of other central themes. Not a failing grade, but a long way from an A+.
The study of violin hole shapes, communicated originally in a publication led by biomedical engineer Hadi Nia, is one of my favourite examples of cultural evolution. It’s always difficult to infer the precise nature of evolutionary processes that connect distant ancestors to specific present-day entities, but there is a compelling case here that major improvements were driven by trial and error based on random changes in hole shape that happen during production. Contrary to frequent assumptions, there was no genius violin maker that looked at a simple hole centuries ago and envisioned the elegant f-shape to maximize what researchers now call “air resonance power efficiency”. Rather, just like the way much of biological evolution occurs, improvements were discovered by random happenstance, accumulating gradually over a period of centuries.
On the flipside, biological evolution can involve processes often thought to be specific to cultural evolution, such as non-random variation generation and multiple pathways of inheritance. In short, while we might think of cultural and biological systems as evolving in fundamentally distinct ways, in fact they overlap on all possible axes we might think distinguish them. In Everything Evolves, I illustrate these axes by analogy using the “Evolutionary Soundboard”, which contains a series of dials that characterize the key processes that underly all evolutionary systems. Whether we’re considering the evolution of cells or cell phones, violins or violets, the same fundamental processes are at play.
--Marshal Zeringue
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