Some books seem like they were written with you in mind. I look at this cover and read the title, with words like fate, chance, and evolution, and I think this is exactly up my alley. And. . .it kind of is. No matter how hard I tried, though, I simply did not love this book. Jonathan Losos isn’t a bad writer, but I think at times he is too close to his own studies to know where to edit them down for the casual science enthusiast. On the writer scale, he falls somewhere between a “science writer” (Me: “OMG, science is so cool!”) and a “scientist” (Me “OMG, can we please find this man a ghostwriter?”). I’m not saying Losos tries too hard, but the number of times he uses the word “gedanken” makes me think he missed that vocabulary question on the SATs and has been trying to make up for it ever since.
To sum up the premise of this book: You might think that there are infinite possibilities from which organisms can “choose” when they adapt, but evolution often follows a predictable path for very different organisms when faced with similar environmental demands. Except when it doesn’t. The end.
For example, birds eat seeds. The presence of large seeds results in birds evolving larger beaks to crack them open. This happens to birds that evolve in geographically dispersed locations, demonstrating that evolution came up with the same solution multiple times. In another example, sharks, dolphins, and ichthyosaurs all have similar body types for streamlined swimming. This process of species that are not closely related responding to similar environmental demands in the same way is known as convergent evolution.
“Yes, this will be on the test, Bobby.”
Some scientists take this a step further and speculate that, if there is life on other planets or moons that have oceans, those ocean-dwelling species will likely evolve similar adaptations. The idea is that evolution has come up with an exceptionally good design, so given a similar set of circumstances, it’s likely to come up with the same design all over again. As esteemed paleontologist Conway Morris says, “Show me anything which has only evolved once, and I’ll . . . jump up an say, ‘no, I can give you another example.'”
Indeed, nature is filled with these examples, which is all well and good. But then how do you explain this:
The crazy platypus. Such a freak of nature that scientists in the late 18th century thought it was a hoax, a taxidermied amalgam of different animal body parts sewn together. How come nothing like that has ever evolved again, huh? Some pesky scientists would argue that it has evolved multiple times, at least in terms of the individual parts: the tail is much like a beaver’s, for propelling through water; the fur is thick like an otter’s, to help it stay warm; the feet are webbed like a duck, again for their aquatic lifestyle; the venomous spur is for defense, like a snake. So just because the whole thing looks weird, doesn’t mean there isn’t convergent evolution at work.
Losos also addresses the fallacy that evolution is always a slow-moving process. Certainly the steps taken to get from primordial slime to a fully formed elephant took almost as long as that time you tried to sit through The English Patient, but evolution doesn’t always move at a glacier-like pace. If it did, we wouldn’t have to come up with a new flu vaccine every year; it’s because the virus changes and adapts quickly that we are forced to modify our approach annually. Losos illustrates this idea by describing studies done on guppies by Caryl Parker Haskins in Trinidad. Haskins noticed that male guppies living above a waterfall, which served as a barrier to predators, were brightly colored, whereas the ones below the waterfall, where predators were more plentiful, were drab. After some investigation, he concluded that the colorful guppies wouldn’t last long in a predator-filled area (the colors were, however, an advantage in the mating game). Another scientist, John Endler, came along and decided to really test this color hypothesis by exposing some guppies to predators and others to a predator-free life in a controlled environment, and then observing how their color patterns changed over time. After just five months, Endler was already able to observe that the guppy populations were changing. Those living with predators were producing more offspring with fewer flashy spots; those living in the safe environment were getting flashier. After nine months, the changes became even more extreme.
Guppies without predators be like. . .
I could go on about all the great information in this book. The studies are certainly interesting, which is why I’ll keep this book on my shelf for future reference. At times though, it just goes on and on and on. For reasons I’m not going to try to explain, he begins his concluding chapter with a description of the Na’vi from Avatar.
So I’ll leave with a final thought. If Jonathan Losos were to hit the reset button and rewrite this book with a new editor, would I find it more compelling? That’s a gadanken experiment I can get behind.