Transylvanian Dinosaurs

CHAPTER 8. Alice and the End

194 CHAPTER 8 Alice and the End Ancient Transylvania now makes sense as a land of contingency, a region where any number of unpredictable events provided the raw material for what would become the history of members of its dinosaurian fauna. Emerging from a synthesis of cladistics, paleogeography, heterochrony, and life-history strategies, the significance of the Transylvanian dinosaurs comes from what their evolution tells us about historical contingency. It’s even more exciting when studies like this transcend their intrinsic appeal to provide insights into larger issues in evolutionary biology. We think maybe this has happened here. To get there, however , we should probably first revisit one of the finest adventures to come from children’s literature. Enter Charles L. Dodgson, a British mathematician , deacon, and photographer, but better known throughout the world as Lewis Carroll, the author of Alice in Wonderland (1865) and Through the Looking Glass (1872). Through the Looking Glass begins with Alice dreaming of being in a house where everything was in reverse, left to right, as if she had passed through a mirror. Outside was a beautiful garden, but she wanted to see it better from a nearby hill. However, as she followed what appeared to be a very straight path to the hill, she found that it led her back to the same house. When she tried to speed up, she instead immediately returned and crashed into the house. Eventually, Alice found herself in a patch of very vocal and opinionated flowers, telling her that someone Alice and the End 195 (the Red Queen) often passed through this garden. When the Red Queen finally came into view, Alice tried to catch up with her, but to no avail; the Red Queen quickly disappeared. One of the roses in the garden advised Alice to walk in the opposite direction and, by this reversed action, she immediately came face-to-face with the Red Queen. As the Red Queen led Alice directly to the top of the hill, she explained to her that in this world, hills can become valleys, valleys can become hills, straight can become curved, and progress can be made only by going in the opposite direction. At the top of the hill, the Red Queen began to run, faster and faster. Alice, following after the Red Queen, was further perplexed to find that neither one of them seemed to be moving. When they stopped running, they were still in exactly the same spot. Alice remarked on this, to which the Red Queen responded: ‘‘Now, here, you see, it takes all the running you can do to keep in the same place.’’ We haven’t the slightest idea whether Lewis Carroll gave much thought to the evolutionary implications of Alice’s adventures with the Red Queen, although it might have been possible—Carroll lived no more than 45 km from Darwin’s Down House home in the neighboring county of Kent, and the two published their works just 13 years apart (On the Origin of Species was first released in 1859). Nevertheless, it took a century, and travel nearly 7,000 km to the west, for Carroll’s Red Queen to provide the moniker for a major shift in our understanding of evolutionary dynamics. In 1973, Leigh Van Valen (figure 8.1), an evolutionary biologist and vertebrate paleontologist at the University of Chicago, published a paper that explored whether long-lived lineages were more resistant to extinction than short-lived groups. According to Darwin, natural selection weeds out the poorer- and promotes the better-designed organisms, thus improving the fit with their environment. If so, Van Valen then reasoned that a species should have less probability of becoming extinct in the future if it has already been around for a while. In other words, long-lived species are presumably the ones that have been finely tuned by natural selection. To test this proposition, he examined the rates of extinction for a large number of evolutionary lineages, compiling what amounts to life tables for a variety of organisms, from clams to mammals.∞ To Van Valen’s surprise, his data showed that the probability of extinction remains constant, independent of whether the species has been in existence for a long or a short time. In order to explain this seeming 196 transylvanian dinosaurs Figure 8.1. Leigh Van Valen (b. 1935), portrayed as Alice being pulled through an evermoving landscape by...