“Both these cases are most parsimoniously interpreted as sympatric speciation,” said Jerry Coyne at the University of Chicago. Still, he questioned whether the species are truly sister taxa, and didn’t reach the island or crater lake from separate invasions from a source population. “If there’s a little bit of hybridization between the species, they’re going to become genetically more similar to each other than either is to a mainland species,” Coyne told The Scientist. “They’d look like sister species when they’re not.” He noted that the two palm species do indeed form hybrids, albeit infrequently.
Nick Barton is equally pessimistic, saying that “it’s so hard to even demonstrate one example” of sympatric speciation. Maybe if some of the examples involved chromosomal inversions, Barton would be more willing to accept them as evidence of sympatric speciation. However, one of our best examples of sympatric speciation via chromosomal inversions is actually allopatric speciation with reinforcement. Allopatry with reinforcement — it’s the new sympatric speciation people.