Re: Re: DNA sequencing

dave evans (T442119@RUTADMIN.RUTGERS.EDU)
Mon, 02 Oct 95 23:13 EDT

> Fernando,
> >One of the
> >interesting result was that Roridula is sister to Darlingtonia,
> >Sarracenia, and Heliamphora. Another is that Byblis is close to
> >Pinguicula and Utricularia and VERY far from Cephalotus, with which it is
> >often placed.
> only suggest that _Roridula_ belongs to a huge and probably heterogeneous
> complex of many loosely related families (something like Corniflorae) of
> low-intermediate "advancedness" (if something like this does exists), the
> Sarraceniaceae being (+/-) associated to the same clump but very probably
> from a rather radically different end.

So it's more like a 2nd cousin type of relationship? ;)

> > The Drosera called my attention the most. First of all,
> >they really are close to Nepenthes.
> This is not new but probably wrong in this oversimplified statement (well,
> they are of course both dicotyledons...). Furthermore, the most interesting
> families in this respect (viz. Dioncophyllaceae and Ancistrocladaceae) have
> not been considered.

I thought Fernando was emphasizing the relationships with regard to
CP and meant that Drosera closer to Nepenthes than other CP. Did I
get that right? Jan, are you saying that is wrong? I'm not sure but
it seems you guys aren't "on the same wavelength" so to speak.

> > Second, Drosophyllum stems off from
> >Drosera before Dionaea and the first Drosera to stem off is D.regia.
> This is not at all new, and even purely morphological comparison indicates
> this. Again, important species (e.g. _D.meristocaulis_) have not been
> considered at all.

Yeah, it isn't hard to reach that conclusion without the DNA testing
but wouldn't this lend support to the validity of this type of comparison?

> >I'd mentioned that a thick-rooted species like D.binata probably
> >originated the tuberous Drosera while D.petiolaris and the pygmies must
> >be closely related groups, due to certain morphological similarities
> >(like small lamina and long, narrow petioles, present in most species).
> I am happy to see you are eventually returning to comparative morphology.
> So there remains some hope for me. Your first hypothesis is not as highly
> speculative as you have stated, I think. But the "pygmies" need not at all
> be closely related to the _D.petiolaris_-complex. In fact, I consider them
> to be rather remote (no gemmae formed in the latter, styles never divided
> vs. always multifid, the first confined to subtropical S AU to N.Zeal., the
> latter from tropical AU to N.Guin., caryological differences).

Jan, perhaps gemmae are not really that big of a jump. Has anyone
studied the gemmae to see what part grows into the new plant? Does
the area close to where the petiole is/would be grow like a D.petolaris
cutting or does the entire gemmae sort fold out into a new plant? If
it's the latter case, I would think that indicates a more remote rela-
tion. Oh, what is meant by 'caryological' the dictionary here is of
no help.

Dave Evans