[Taxacom] Ghost moth as a subduction zone weed

John Grehan calabar.john at gmail.com
Tue Sep 1 11:13:18 CDT 2020

When It comes to the origin of allopatry there is no need to attribute the
distributions to sequential chance dispersal - i.e. attribute
differentiation to movement which sets up a tension between he need to
explain both range and differentiation to movement - i.e. mobility to get
there but somehow also insufficient to prevent isolation (so we often get
references to mysterious and miraculous in the dispersal literature).
Vicariance of a widespread ancestor does not set up this tension since
range expansion is just normal observable ecological dispersal and is not
responsible for isolation and differentiation.

If some kind of scientific evidence was presented for center of origin and
chance dispersal (that is not observable) that would be one thing, but
simply saying it as a matter of belief is another, and that is what Ken and
other center of origin-dispersal theorists do. The only 'evidence' offered
in recent times was the idea that fossil calibrated molecular dates
precluded earlier tectonically mediated origins. But this has now been
shown to be fraudulent [the molecular date theory, not the
practitioners who innocently, but erroneously, adopted the notion out of
enthusiasm or zeal]).

But it is not simply a matter of saying that one (center of origin) is good
as the other (vicariance). The latter can be supported by evidence in the
form of shared patterns between taxa with very different ecological
dispersal capabilities (as with Phassodes sharing the pattern in common
with frogs for example). Also by tectonic correlations, again as with
Phassodes being correlated with the Vitiaz arc. The frogs are definitely
not in New Guinea, and neither are various other taxa that 'skip' the
region. Tectonic correlates are found globally with a vast range of animal
and plant groups with 'good' and 'bad' means of dispersal. I view this as
one of the great discoveries in late 20th and early 21st
century evolutionary theory.

It is also not necessary to postulate 'migrations' to or from Hawaii to
explain biotic connections with continents. Given that there have been
various island arcs and virtual micro-continents that have been moved apart
with the formation of the Pacific plate. These movements would certainly
provide a geological mechanism for the origin of such relationships.

It is my belief (and I note that it's just a belief) that ghost moths
require a higher level of ecological and geographic stability and
continuity to maintain populations than what occurs deeper within the
Pacific. Hence 7 genera in New Zealand, but only one species in New

I suspect the vitiaz arc maintained comparatively large areas of land, at
least earlier in its formation, which did provide sufficient ecological and
geographic continuity for Phassodes to persist in the region, whereas more
eastern fragments such as Tonga did not maintain that viability.

John Grehan

On Tue, Sep 1, 2020 at 10:56 AM Kenneth Kinman via Taxacom <
taxacom at mailman.nhm.ku.edu> wrote:

> Hi Hubert,
>        I am not making the assumption that clades have to originate on
> continental crust.  And yes, the Hawaiian Islands have lots of life.
> However, I don't think there are any species of ghost moths (Hepalidae) in
> Hawaii (I would be shocked if there was).
>        The reason I lean toward the idea of Phassodes having originated in
> New Guinea is their very limited dispersal potential.  I am frankly amazed
> that they made it as far as Samoa.   I would not even rule out the
> possibility that they were somehow accidentally transported by humans.  At
> least that is something to consider.
>         Anyway, the question in my mind is whether the
> Phassodes-Abantiades clade arose in the north (New Guinea) and then spread
> south into Australia (as Abantiades) or if that clade arose in Australia
> and spread north into New Guinea (as Phassodes).  I suspect it originated
> in Australia (or even Antarctica?) and then spread north into New Guinea
> (and that the sister clade was in South America or Antarctica).   Whether
> there is enough material to test that hypothesis, I don't know, but it
> might be something worth considering.
>                        ---------------Ken
> ________________________________
> From: Hubert Turner <turner at casema.nl>
> Sent: Tuesday, September 1, 2020 6:46 AM
> To: Kenneth Kinman <kinman at hotmail.com>; taxacom at mailman.nhm.ku.edu <
> taxacom at mailman.nhm.ku.edu>
> Subject: Re: [Taxacom] Ghost moth as a subduction zone weed
> Hi Ken,
> Why should the assumption always be that a clade originated somewhere on a
> large fragment of continental crust? If you go to e.g. the Hawaii islands
> there is a lot of life around, even though even the oldest (now submerged)
> island probably never was connected (or close) to any continent. So, in my
> view an ancestor on such an island had as much chance to migrate to a
> continental terrane as a continental ancestor had to move the other way
> round (bar other conditions such as aquatic or aerial currents favoring one
> direction over the other), meaning the assumption is false. Life after all
> probably originated in the sea, so the first sub-aerial excursion could
> have taken place anywhere, not necessarily on continental crust.
> My two cents worth.
> Hubert Turner, PhD,
> independent scientist
> phylogeny, SE Asian biogeography
> On 01/09/2020, 10:46, "Taxacom on behalf of Kenneth Kinman via Taxacom" <
> taxacom-bounces at mailman.nhm.ku.edu on behalf of taxacom at mailman.nhm.ku.edu>
> wrote:
>     Hi John,
>            I guess we probably won't know any time soon, but my prediction
> is that Phassodes does occur in New Guinea (and that it probably originated
> there).  That would have given the genus a solid piece of land for its
> entire history, and help explain its ability to survive the less permanent
> nature of the volcanic islands to the east.   Therefore, the spread of this
> genus across these islands could well have happened well after it
> originated.  And the metapopulation dynamics probably less complex than a
> genus that was truly endemic to the volcanic islands.
>                                  -------------------Ken
>     ________________________________
>     From: John Grehan <calabar.john at gmail.com>
>     Sent: Saturday, August 29, 2020 9:40 AM
>     To: Kenneth Kinman <kinman at hotmail.com>
>     Cc: taxacom <taxacom at mailman.nhm.ku.edu>
>     Subject: Re: [Taxacom] Ghost moth as a subduction zone weed
>     Hi Ken,
>     Occurrence in New Guinea is a perfectly reasonable possibility,
> although geographic proximity is not always a predictor of occurrence in
> this region as there are many well known taxa that occur on surrounding
> islands but skip New Guinea itself. Admittedly in the case of Phassodes
> this is an insect that is not well known or extensively collected, even
> from Fiji where it has been mostly recorded (and even then only from one of
> the two main islands - perhaps because one has the international airport
> and most collectors stay with that island). The moth is probably very
> abundant in all localities, but appears to be rare or infrequent at light.
> On that basis and given the new Solomons record it is reasonable to suppose
> that its distribution range could be more extensive. However, New Guinea
> itself has been quite well collected for Lepidoptera for more than a
> century and while other ghost moths have turned up (but only three genera
> so far, and all also present in Australia) I would put money (if I had any
> to spare) on the absence being real.
>     The current range of Phassodes does conform to a pattern of other
> non-New Guinea distributions that extend north of New Guinea between the
> Philippines and Fiji-Tonga, including a group of frogs. My present
> anticipation is that Phassodes is really part of that pattern. The
> outstanding question is to what extent that range includes or not the more
> northwestern islands of Bougainville, New Britain, and New Ireland. If one
> were to consider geographic proximity it would be these islands are much
> closer than New Guinea. They currently have no records of any ghost moths
> as was noted by collectors very early in the literature. If Phassodes were
> to one day turn up in New Britain region of New Guinea, I would see e the
> northern margin, particularly the Finistere Range as more of a possibility,
> but there is a major biotic difference between New Guinea and New Britain
> in other groups, including (if I recall the number correctly) a 70%
> difference in the bird fauna, even though the geographic gap is very small.
>     What is needed (as far as Phassodes might be concerned) is future
> collecting that includes a focus on ghost moths (that might fly at dusk for
> example) in the rest of the Solomons as well as further north. I guess that
> it is not likely in my lifetime. The Solomons specimen turned up entirely
> by fortuitous accident when my co-author visited an insect fair in Europe
> some years ago and saw the specimen for sale by a commercial collector.
> Right place and right time or this occurrence may still have remained
> obscure. Ghost moth taxonomy is sometimes like running in the dark.
>     John Grehan
>     On Fri, Aug 28, 2020 at 9:19 PM Kenneth Kinman via Taxacom <
> taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>> wrote:
>     Hi John,
>             Interesting.  But now that there has finally been one specimen
> discovered in the Solomon Islands, wouldn't it seem somewhat likely that
> there are also species of Phassodes in Papua New Guinea that have not yet
> been discovered.   The Solomon Islands are closer to New Guinea than they
> are to Fiji and Samoa.
>                                     --------------Ken
>     ________________________________
>     From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu<mailto:
> taxacom-bounces at mailman.nhm.ku.edu>> on behalf of John Grehan via Taxacom
> <taxacom at mailman.nhm.ku.edu<mailto:taxacom at mailman.nhm.ku.edu>>
>     Sent: Friday, August 28, 2020 1:50 PM
>     To: taxacom <taxacom at mailman.nhm.ku.edu<mailto:
> taxacom at mailman.nhm.ku.edu>>
>     Subject: [Taxacom] Ghost moth as a subduction zone weed
>     For those interested, following article provides a biogeographic model
> for
>     the origin of a ghost moth genus (Phassodes) endemic to some Pacific
>     oceanic islands. Accessible at
>     http://hbs.bishopmuseum.org/pubs-online/bmop.html
>       Taxonomic revision and biogeography of Phassodes Bethune-Baker, 1905
>     (Lepidoptera: Hepialidae), ghost moth descendants of a subduction zone
> weed
>     in the south-west Pacific. Grehan, J.R. & Mielke, C.G.C. Bishop Museum
>     Occasional Papers 136: 1–37 (2020)
>      Abstract. Phassodes Bethune-Baker, 1905 is distributed in Fiji (P.
>     vitiensis (Rothschild, 1895)), the Solomon Islands (P. walteri sp. n.),
>     Samoa (P. samoa sp. n.), and American Samoa (P. tutuila sp. n.). It is
> the
>     only genus of Hepialidae endemic to oceanic islands. Monophyly of the
> genus
>     is supported by four unique features, and a sister group relationship
> with
>     the Australian genus Abantiades Herrich-Schäffer, 1855 is supported by
> four
>     shared derived features. There are also some features shared between
>     Phassodes and other genera: a) the southern Andean genus Andeabatis
> Nielsen
>     & Robinson, 1983 (shape and structure of the male genitalia), b) the
>     Peruvian Viridigigas Grehan & Rawlins, 2016 and c) the Chilean
> Puermytrans
>     Viette, 1951 (presence of a basal forewing scent gland). The
> distribution
>     of Phassodes coincides with the Vitiaz Trench, an extinct subduction
> zone
>     that marks a former boundary between the Indo-Australian and Pacific
>     plates. It is proposed that the common ancestor of Phassodes and
> Abantiades
>     diverged through vicariance when the subduction zone along the east
> coast
>     of Australia (East Gondwana), along with its island arc, began
> retreating
>     into the Pacific between 90 and 75 Ma. Survival of the genus on
> volcanic
>     islands is attributed to metapopulation dynamics, with continuous
>     transference of populations from older, subsiding islands to newly
> emergent
>     ones. This model suggests that Phassodes species originated much
> earlier
>     than the individual islands they now occupy.
>     _______________________________________________
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