This particular shambling zombie takes another punch now with news about identical twins.
What Dr. Swamidass has going for him is primarily a quirk of semantics.
If textbooks evolve, then what we thought we knew yesterday is no longer true today.
There’s a famous scene in an Indiana Jones movie where the hero barely makes it under a closing gate descending on him in an underground tunnel.
Independent groups of researchers (e.g., Hössjer et al. 2016), more or less skeptical of common ancestry, have suggested the alternative model of initial heterozygotic diversity.