Extra readings which are referred to or directly related to the assigned readings for Sept 21st:
Coyne and Orr's chapter from Speciation (2004) and Velasco (2008) both refer to a piece which defends the BSC against the charge that it distorts evolutionary history.
Baum and Donoghue (1995) refers to Phylogenetic Species Concepts which are historical in nature. They give just one example for discussion - a PSC based on gene tree concordance. This view was first developed in Baum and Shaw (1995). Less strict and so improved versions have been discussed a few times since, most recently in Baum (2009) and Velasco (2010).
Velasco (2008) criticizes an argument from LaPorte (2005). LaPorte responds (indirectly by responding to a number of objections) in LaPorte (2009).
Finally, Coyne and Orr (2004) contains an Appendix which has criticisms of a number of alternative species concepts including three versions of the PSC.