Response Questions gr

1. The earlier error in classifying the animal fossils found in the Burgess shale was caused by a view of evolution in which things have steadily become more diverse, more complex, and simply better than what came before. Along with this view, the original interpretation of the Burgess shale was an attempt to shoehorn all those animals into currently existing groups. Gould asserts that the original source of the that model of thinking was the iconography of A.O. Lovejoy's The Great Chain of Being.

2. The shape of the phylogenies or evolutionary trees imply not only the path that evolution takes over time, but of the general perceptions of that path due to their shape. Some of the perceptions being that as we go up the tree and into the branches things get better or more refined into the most successful iteration of a species. The truth being that all the verticality confirms is that the lower the organism, the older it is, and that the organisms at the bottom are no less complex than the ones at the top. The other notion he feels is looked over is that when an animal is highlighted as a textbook example of evolution, such as a horse, which is by now the lone twig on that branch, it is not the refinement of the "winning" species that has evolved to perfection (and to the elimination of all other varieties) but in fact, just an indication of an unsuccessful branch of evolution. Some of the "casual factors" of evolution are if the area or habitat an organism inhabits is destroyed or altered drastically, it can significantly affect which traits are then the most useful to the new situation, and thus which traits become more prevalent and which die out.

2b. To replay the tape of life means if we could recreate the events of history and evolution as an experiment we would do so and see if the results would be the same. This is an interesting idea to Gould because the prediction is that our current paths of evolution are the results of so much chance, that the same experiments, or the replaying of the tape would result in completely different paths of evolution. If Cuvier were alive, I think he would like the idea that these catastrophes could play out differently with many variables that would lead to drastically different results of the evolutionary paths of many species, including which species have reached extinction. I don't think his views in line with catastrophism would jive with this idea of "casual factors" that could alter the course of evolution, since his views seemed to dictate that a number of massive catastrophes, not very casual, caused the extinction of animals that were no longer here, and affected the animals that are here now.

3. Disparity v.s. diversity would be the to compare the amount of twigs on any branch on the tree of evolution. The more twigs, the greater the diversity of the organisms within that group, while the fewer, the more disparate. Ants represent a diverse group as there are hundreds of varieties and types all over the world that are closely related to each other.

4. The American Museum of Natural History arranged their mammal display to reflect an order of how and when groups branched off from each other, getting rid of a bias in the idea of progress through chronology.

-guillermo