Date: Thu, 24 Nov 2011 19:45:11 +0100
From: Lars <
larsmaillist@googlemail.com>
Subject: Re: [Aroid-l] Adelonema
To:
aroid-l@gizmoworks.comMessage-ID: <
4ECE90B7.2060805@gmail.com>
Content-Type: text/plain; charset=3DISO-8859-15; format=3Dflowed
Hello everybody,
sorry for this mail coming a bit late. I wanted to add something to the
discussion of the aroid biogeography but had problems posting here on
the list.
Well, if you can read this, it means it finally worked. Thanks Steve for
figuring out the=0A problem!
I am just working on the dating and biogeography of the family for my
phd. Basically, I use molecular data and assign fossil to certain nodes
in order to get minimum ages for all other nodes.
It also means, that I don't even have a glimpse of the deep
understanding in the ecology, morphology, and taxonomy of Tom and Peter
(and others), as I just work since a few years with Araceae and mainly
from a molecular point of view.
Having said that, here are some of my results.
(The ages are minimum ages and therefore might be considerably older.)
The spit between Adelonema and Homalomena is relatively young, at least
25 Ma. Maybe 40 Ma is more realistic, but I don't think it is much
older. Although I would like to explain it by vicariance (maybe in a
very warm period in the Paleocene, when there was subtropical climate in
Antarctica and a land connection to Australia). The direction would=0A be
from South America to SE Asia, as Peter told me Philodendron is basal to
the two genera in his more detailed dataset. It is very unlikely that
they got dispersed over the pacific, but not impossible. There have been
some weird long distance dispersals.
If it would be 50-60 Ma a pathway through Antarctica and Australia could
have been possible.
The same young ages (20-30Ma) are in the disjunctions of the Lasioideae
and Monstera (which is in a South East Asian clade).
The split between Philonotion and the rest of the Schismatoglottideae on
the other hand is quiet some time older, at least 45 Ma. With the error
boundary and considering it as minimum a dispersal in the Paleocene
might have been possible.
The Bornean Nephthytis bintuluensis groups with Aglaonema and Aglaodorum
(both from SE Asia), while the rest of Nephthytis groups with Anchomanes
and Pseudohydrosme from Africa. The split=0A between these two groups was
at ~40 Ma.
Rhaphidophora, Amorphophallus, and Arisaema went somewhen in the Miocene
to Africa.
Peltandra (eastern North America) and Typhonodorum / Arophyteae
(Madagascar) have spilt in the Eocene and have had ancestors in Asia
(good fossil record). So it must have been a relatively continuous
connection, or movement later to Africa at the one side and crossing the
Bering Strait at the other.
The Origin of the Araceae is a bit more difficult. The ages are not
really clear, as for the molecular dating with fossil assigned as
minimum ages you have to have a maximum bound at the base.
But they surely go back to the Early Cretaceous (fossil record), maybe
even Jurassic. The true Araceae (without Lemnoids and Proto-Araceae)
most probably come from Gondwana. But reconstructing the real origin it
has to be taken into account the free floating (and mostly world wide=0A
distributed Lemnoids), the today probably only remnant basal
Gymnostachys (Australia) and Orontioideae (Laurasia), and the
Alismatales, the next sistergroup of the Araceae (many in the northern
hemisphere, or marine, or sweet water plants and world wide
distributed). That leaves everything open for speculation and any
reconstruction there is difficult, so to answer an earlier question of
Christopher:
No, there is no data robust enough to give an unambiguous result for the
origin (I guess that is what you mean with center of radiation).
At least that is what the molecules and some modern methods let suggest.
Very best,
Lars
(
l.nauheimer@gmail.com)
Am 24.11.2011 19:19, schrieb Steve Marak:
> That let me see the problem.
>
> Aroid-L has you as "
larsmaillist@gmail.com", but your posts are coming
> from "
larsmaillist@googlemail.com". From Google's side, the two are the
> same, so you are still getting posts from the list, but from Aroid-L's
> side they are different, so you can't post.
>
> The fix of course is to get your address changed in Aroid-L. I have tried
> to do this from the administrative interface, but it has not changed. I'm
> hoping this is because it has sent you a confirmation and is waiting on
> your response. If not, then we can still change it, but it will require
> more work.
>
> Steve
>
>
> On Thu, 24 Nov 2011, Lars wrote:
>
>> Am=0A 22.11.2011 10:18, schrieb Peter Boyce:
>>
>> There a quite some "shared" clades for this trans ecozone distribution:
>>
>>
>>
>> The `obvious' ones are the Schismatoglottis Alliance [Philonotion][Cryptocoryneae+Schismatoglottideeae]
>>
>>
>>
>> The Monsteroideae (with notably Rhaphidophora in W Africa, and IndoMalaya)
>>
>>
>>
>> The Lasioids, especially Anaphyllopsis (Neotropics) Lasimorpha (W Africa), Anaphyllum (India),
>> Lasia/Cyrtosperma/Podolasia (Asian tropics)
>>
>>
>>
>> =0A The extraordinary Nephthytis in West Africa& N Borneo
>>
>>
>>
>> More subtly Aglaonema/Aglaodorum (Asian tropics) is compellingly linked to almost wholly African
>> Nephthytideae.
>>
>>
>>
>> The most `complete' clade is in American Journal of Botany 98(4), 654-668] - Cusimano et al 2011.pdf
>>
>>
>>
>> Peter
>>
>>
>>
>> From:
aroid-l-bounces@www.gizmoworks.com [mailto:
aroid-l-bounces@www.gizmoworks.com] On Behalf Of
>> Christopher Rogers
>> Sent: Tuesday, 22 November, 2011 1:58 AM
>> To: Discussion of aroids
>> Subject: Re: [Aroid-l] Adelonema
>>
>>
>>
>> Thank you, Peter and Tom!
>>
>>
>>
>> So, thinking biogeographically, am I understanding you correctly that Adelonema and Homalomena are sister
>> taxa, having split roughly 75mya? Even 75 mya, these regions were never near each other. Do you think that
>>=0A these genera used to be distributed from South America, across Africa to Southeast Asia? Are there any sister
>> clades in Africa for these genera or for other genus groups with a similar South American/Asian distribution?
>>
>>
>>
>> Happy days,
>>
>> Christopher
>>
>>
>>
>>
>>
>> On Mon, Nov 21, 2011 at 2:27 AM, Peter Boyce<
phymatarum@googlemail.com> wrote:
>>
>> Hi Marek, and other aroid-l folks,
>>
>>
>>
>> Tom as nicely summed up the situation; allow me to put some more meat on the=0A bones.
>>
>>
>>
>>
>>
>> We have two independent sets of molecular data that show convincingly that the Neotropical species currently
>> assigned to Homalomena do not belong there NOR do they belong in Philodendron - as had been suggested by a
>> previous study [Molecular phylogeny of the genus Philodendron (Araceae): delimitation and infrageneric
>> classification - [Botanical Journal of the Linnean Society 156: 13-27] - Gauthier, Barab?& Bruneau 2008].
>>
>>
>>
>> The `coarse' detail is a molecular clock study by Nauheimer et al, which gives dates the diversification of
>> the Neotropical and Paleotropical clades at a minimum of ca 75 MYA.
>>
>>
>>
>> The 'fine detail' comes from a molecular study we've done in=0A Malaysia as part of our work on the "true"
>> Homalomena species. This paper is in prep. now, a spin-off from the phylogeny work done by two of our Master's
>> projects (Ng Kiaw Kiaw - who works on chemical profiling - and Hoe Yin Chen, who's working on pollination and
>> floral fragrance analyses).
>>
>>
>>
>> While Curmeria is `better known', the earliest name is Schott's Adelonema.
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