Hi, Frank. Not having a go at you in particular, but this message
happened to be the one that provoked me ...
franklin e. bliss writes:
The missing link here is recognizing that many, many primitive
(poor term) organisms exhibit parthogenesis. [...] This does
seems to be a trait which is shared by many "simple" organisms
(excuse the term please)
Isn't it time to unapologetically reintroduce that useful old term
"primitive"?
I know that it's orthodox to say "basal", but as we all know when we
stop to think about it, both branches of a any tree are equally
"basal" -- in other words, basalness is a relative property, and a
taxon can only be considered basal _relative to_ a clade -- for
example, _Cetiosaurus_ is basal relative to Neosauropoda; but if
you're studying cetiosaurids, then _Jobaria_ is basal relative to
Cetiosauridae.
Plus of course what we mean when we say "primitive" is not really the
same thing that we mean by "basal". The former describes
morphological similarity to an ancestor, the latter a phylogenetic
topology. To couch it in measurable terms, in the context of a
phylogeneric analysis, a "primitive" member of a clade is one that has
a small number of character-state transitions from MRCA.
Now why is that concept considered objectionable? Seriously, why?
_/|_
___________________________________________________________________
/o ) \/ Mike Taylor <mike@indexdata.com> http://
www.miketaylor.org.uk
)_v__/\ Never look a gift-chicken in the beak.