Genus is basically defined by being the bin that lies above species. It's a beauty contest, as is family, order, you name it. OK, a phylum is supposed to have a unique body plan, although that's harder to pin down than it sounds.
Speciation means something in extant sexual species. (In the fossil record, it's back to being guesswork.) Everything above it is arbitrary mush for a long ways.
You have pegged your definition in mush.
Speciation means something in extant sexual species. (In the fossil record, it's back to being guesswork.) Everything above it is arbitrary mush for a long ways.
You have pegged your definition in mush.
Interesting last sentence. You agree with me that the definitions of speciation are nonsense but you call my calling for at least a genus change for macro-evolution to be mush. It is you who has been insisting that the silliest kind of speciation - such as a change in bird call - be called macro-evolution, not me. Genus requires new capabilities, new abilities, changes in phenotype and that is exactly why I said a change is genus is required to show macro-evolution.