OK. The author says up front that it is an opinion piece for starters but also references some out of date science with respect to genetic distance. Also basing his thoughts on old science (not his fault it was 2008). The science has progressed and some of those blanks he fills with deduction and belief have been filled in with new tech and evidence. Here is a link to newer info that has been peer reviewed and results replicated.

https://genomebiology.biomedcentral.com/articles/10.1186/s13059-019-1684-5#Sec9