[Taxacom] John Grehan & great apes

[Robin Leech]

Dear All,
>       I just want to make clear that I am not saying that John should
> "let up" on challenging the hypothesis that humans and chimps form an
> exclusive clade.  However, rather than yet another paper rehashing
> arguments that have already been made, it would be more informative and
> interesting if John used his data to explore the third (and generally
> neglected) possibility.                  
>        Namely, a phylogenetic topology in which orangutans split off as
> a first single clade, humans split off as a second single clade, and
> then chimps and gorillas together form an exclusive clade.  That would
> explain the similarities between orangutans and humans not as
> synapomorphies, but rather as symplesiomorphies of the great apes that
> were subsequently lost or modified in chimps and gorillas.  There would
> probably be more molecular support for this as well (since I have been
> unable to find any molecular support for humans and orangs forming an
> exclusive clade).  Rigorously testing this third "middle-ground"
> topology would inject some new life into this (now tiresome) debate
> between the other two camps.  
>       -------Cheers,
>                         Ken Kinman