Morphogenera, monophyly, and macroevolution

Morphogenera, monophyly, and macroevolution.

Jablonski and Finarelli (1) suggest that morphogenera, even when they are nonmonophyletic, serve as good representatives for large-scale evolutionary studies. We feel there are two issues that warrant further discussion. First, the test used to evaluate the effect of using nonmonophyletic groups for macroevolutionary studies was not conservative and thus does not provide strong evidence about t...

Speciational view of macroevolution: are micro and macroevolution decoupled?

– We introduce a simple computational model that, with microscopic dynamics driven by natural selection and mutation alone, allows the description of true speciation events. A statistical analysis of the evolutionary tree so generated captures realistic features showing power laws for frequency distributions in time and size. Finally, some possible interpretations of the absence of punctuated d...

Chance and Macroevolution*

When philosophers of physics explore the nature of chance, they usually look to quantum mechanics. When philosophers of biology explore the nature of chance, they usually look to microevolutionary phenomena such as mutation or random drift. What has been largely overlooked is the role of chance in macroevolution. The stochastic models of paleobiology employ conceptions of chance that are simila...

Genetics, Paleontology, and Macroevolution

Mass extinctions and macroevolution

—Mass extinctions are important to macroevolution not only because they involve a sharp increase in extinction intensity over ‘‘background’’ levels, but also because they bring a change in extinction selectivity, and these quantitative and qualitative shifts set the stage for evolutionary recoveries. The set of extinction intensities for all stratigraphic stages appears to fall into a single ri...