Annotated Bibliography

Chester Hartsough

Bond, J. E. and B. D. Opell (1998). “Testing adaptive radiation and key innovation hypotheses in spiders.” Evolution 52(2): 403-414. Bond and Opell contend that that the derived trait of viscous adhesive capture threads among the araneoids is a key innovation that has led to their diversification. Three criteria must be met for a trait or suite of traits to qualify as a key innovation: 1) the trait must be derived 2) the trait must confer a functional advantage over the ancestral trait 3) the trait must be correlated with an increase in species richness for lineages possessing the trait.

Farrel, B. D. and C. Mitter (1994). “Adaptive radiation in insects and plants: Time and opportunity.” American Zoologist 34(1): 57-69. This paper examines the evolutionary relationship of insects and plants and how that relationship may or may not have led to insect and plant diversification. The authors conclude that diversification in insect and plant lineages is the result of ecological opportunities over evolutionary time.

Frumhoff, P.C. and Reeve, H.K. (1994) "Using phylogenies to test hypotheses of adaptation: a critique of some current proposals." Evolution 48(1): 172-180. As the title suggests, this paper critiques several general methods of testing hypotheses of adaptation that use reconstructed phylogenies. The authors' conclusions are that phylogenetic tests of hypotheses of adaptive character evolution are not as explanatory as generally portrayed in the literature.

Goudet, J. (1999). “An improved procedure for testing the effects of key innovations on rate of speciation.” American Naturalist 153(5): 549-555. This paper is heavy on the statistics; I struggled and failed to make sense of the three tests Goudet outlines in this paper. He builds on previous work of Mitter et al. (1988) and Slowinski and Guyer (1993). He seeks a less conservative test than Mitter et al. (1988) and to correct problems of error in the Slowinski and Guyer (1993) test.

Guyer, C. and J. B. Slowinski (1993). “Adaptive radiation and the topology of large phylogenies.” Evolution 47(1): 253-263. An informative paper that examines the key innovation theory by analyzing many randomly selected phylogenetic trees. The authors determine that large trees are more lopsided than would be expected if species diverge at random. They offer this as evidence that key innovations do take place and cause the possessing lineage to diversify greatly in respect to its sister lineage.

Hunter, J. P. (1998). “Key innovations and the ecology of macroevolution.” Trends in Ecology & Evolution 13(1): 31-36. This paper summarizes the key innovation concept. Hunter gives a brief overview of the history and evolution of the concept in a limited literature review. He criticizes recent studies that compare species richness of sister lineages for ignoring the fossil record, the higher taxa, and phenotypic diversity.

Hunter, J. P. and J. Jernvall (1995). “The hypocone as a key innovation in mammalian evolution.” Proceedings of the National Academy of Sciences of the United States of America 92(23): 10718-10722. The fourth cusp on the molar is stated to be a key innovation without statistical testing. This finding is based on the great species diversity of mammals with hypocones and the functionality of the hypocone.

Mitter, C., B. Farrell, et al. (1988). “The Phylogenetic Study of Adaptive Zones Has Phytophagy Promoted Insect Diversification?” American Naturalist 132(1): 107-128. This is the paper we discussed in class. It outlines a method for determining whether acquiring a trait has led to diversification in that lineage with the respect to the ancestral trait. Compare multiple sister lineages by counting the species in each lineage. If the acquired trait is richer in species than expected by chance it can be inferred that the trait has contributed to diversification in the lineages that posses that trait. This test was used on the phytaphagous trait and the authors concluded that phytophagy has led to diversification in insects.

Price, P.W. and Roininen, H. (1993). "Adaptive Radiation in Gall Induction." In Sawfly Life History Adaptations to Woody Plants, pp. 229-257. Academic Press. This book chapter is an overview discussion of sawfly galling as an adaptive radiation. It is not an attempt to make a case for gall induction as an adaptive radiation, rather it is assumed to be so. The discussion covers the distribution of gall forming sawflies, the evolutionary process that led to gall forming, and other biosystematics and ecology that pertain to the adaptive radiation of gall forming sawflies.

Rohde, K. (1996). “Robust phylogenies and adaptive radiations: A critical examination of methods used to identify key innovations.” American Naturalist 148(3): 481-500. Rhode criticizes a study by Brooks and Mclennan to espouse his view on and method of identifying key innovations. He knit picks Brooks and Mclennan's study complaining about weak phylogenies and the possibility of their sister group comparisons being meaningless for the great age of the lineages. However, his proposed method of identifying key innovations is not a great departure from the literature to this point: 1) create trees using likely homologous characters 2) examine whether trees are imbalanced 3) use multiple sister group comparisons to identify possible key innovations.

Vellai, T. and G. Vida (1999). “The origin of eukaryotes: The difference between prokaryotic and eukaryotic cells.” Proceedings of the Royal Society Biological Sciences Series B 266(1428): 1571-1577. This paper takes us back to some of our earliest ancestors and proposed key innovations that led to the genetic diversity of eukaryotes. The original view has been that the development of the nucleus came first and engulfment of a protobacterium came second leading to mitochondria and other organelles. Recent evidence points to the engulfment of a symbiont as the key innovation. The power that the protomitochondria provided freed the early eukaryotic cell lineage to grow in complexity.

Wiegmann, B. M., C. Mitter, et al. (1993). “Diversification of carnivorous parasitic insects: Extraordinary radiation or specialized dead end?” American Naturalist 142(5): 737-754. This is a follow up paper to the authors' work on phytaphagous feeding insect lineages (Mitter et al. 1988). Applying the same techniques as their previous work they show that carnivory is not an adaptive radiation for insects. This work was done in some part in response to criticism that the testing of adaptive radiations is done a priori of phylogenetic evidence. Even though they failed to show evidence of an adaptive radiation due to carnivory, they did show that a seemingly diverse group of organisms (carnivorous insects) are not the result of a character (carnivory) preconceived to be the key innovation.