This week, we continue reading about the debate at the 2014 ASN meeting: "Species Diversity Is Dynamic and Unbounded at Local and Continental Scales" by Harmon and Harrison in Am Nat.
Some weeks ago we read Rabosky and Hulbert's paper on how ecology sets limits on species. Now we read the counter debate presented at the last ASN meeting.
We argue that biotas at scales from local communities to entire continents are nearly always open to new species and that their diversities are far from any ecological limits. We show that the fossil, phylogenetic, and morphological evidence that has been used to suggest that ecological processes set limits to diversity in evolutionary time is weak and inconsistent. At the same time, ecological evidence from biological invasions, experiments, and diversity analyses strongly supports the openness of communities to new species. We urge evolutionary biologists to recognize that ecology has largely moved beyond simple notions of equilibrium at a carrying capacity and toward a richer view of communities as highly dynamic in space and time.