Joshua Kohn Mechanism Quotations

An intriguing aspect of this study is that the mechanism for ensuring cross-fertilization is very old, often lost, and never regained. That it is still common despite frequent and irreversible loss implies that this trait confers an advantage to species that possess it, perhaps in terms of reduced rates of extinction.

This is the strongest evidence yet to support irreversibility. If we had not used the genetic data coding for this reproductive mechanism and only inferred the pattern of evolution based on the traits of living species, we would have come to the opposite conclusion and with high statistical support that the trait evolved more than once.