Re: flowering 'juvenilies'
- To: Multiple recipients of list AROID-L <email@example.com>
- Subject: Re: flowering 'juvenilies'
- From: "Eduardo Goncalves" <firstname.lastname@example.org>
- Date: Tue, 20 Jun 2000 20:59:48 -0500 (CDT)
Thanks for your comments. In my post, I just forgot to include a good
definition of both terms. You did it with precision! I hope someone have
other possible examples with other groups in this marvelous family.
>From: Jody Haynes <email@example.com>
>To: Multiple recipients of list AROID-L <firstname.lastname@example.org>
>Subject: Re: flowering 'juvenilies'
>Date: Fri, 16 Jun 2000 19:49:38 -0500 (CDT)
>Yours was an interesting post. I, too, have some knowledge (and an astute
>interest) of paedomorphosis and neoteny--but only in animals. I was not
>the process in plants.
>I feel that these terms should be clarified. Although they both refer to
>"possession in the adult stage of features typical of the juvenile stage of
>organism's ancestor", neoteny specifically refers to sexual maturation of
>'juvenile' stage: "heterochronic evolution whereby development of some or
>somatic features is retarded relative to sexual maturation, resulting in
>sexually mature individuals with juvenile features" (Futuyma, D. J. 1986.
>Evolutionary Biology. Sinauer Associates, Inc. Sunderland, MA.).
>Thus, paedomorphosis refers to the simple possession of juvenile traits in
>adult organism, but does not specify a process; conversely, neoteny is the
>process by which somatic maturation is retarded relative to sexual
>Does this make sense? Anyone else care to comment on this interesting
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>Eduardo Goncalves wrote:
> > Dear Aroiders,
> > The production of sexual parts in juvenile individuals is a
> > morphogenetic "accident", but it is usually explored by the evolutionary
> > history of many groups. There are two morphogenetic processes associated
> > this aspect: Paedomorphosis and Neoteny. Both concern juvenile
> > with mature sexual parts or juvenile structures that are kept active in
> > adult individuals. These phenomenons occur in both plants and animals.
> > evolutionists say that humans are just neotenic apes, because our brain
> > continues to develop for a long time after birth! Anyhow, theses
> > are also know in plants and maybe they are a good natural method to
> > new species. Juvenile (or poorly diferenciated) organs are usually very
> > plastic and can adapt to different conditions. If this ability to be
> > morphologically plastic is important for the effective survival of a
> > species, it can be kept or even "improved" by natural selection.
> > I have one possible example. One of the most morphologically
> > genus in the tribe Spathicarpeae is Spathicarpa. It is small, with
> > differenciated ground tissues and have usually the simplest leaf type in
> > tribe (I mean the same type we find in seedlings of almost all genera
> > the tribe). One of my hypothesis (still in test) is that Spathicarpa is
> > neotenic genus in Spathicarpeae. The same for Urospathella wurdackii
> > G.S.Bunting (now currently recognized as Urospatha wurdackii
> > Hay). It is a Urospatha that flowers with the leaves of seedlings!!!!
> > this kind of leaf is useful in those savannas this species occurs. Or
> > it is just an accident that soon will be erased by natural selection!
> > In the case of the supposed M. dubia that flowers with juvenile
> > flowers, we can make some free speculation about this. In the "normal"
> > environment of the species, maybe it is not a good idea flowering this
> > because pollinators may not be able to find the flowers. Meanwhile, if
> > plant spread to new areas, maybe with smaller trees and different
> > pollinators, it can prove to be successful (in evolutionary aspects), so
> > can diverge from the main species and become ANOTHER species. If
> > can be so creative than me (I don't think so), it is really possible to
> > occur in nature!
> > I hope you enjoy those crazy ideas!! :o)
> > Eduardo.
> > >From: "Peter Boyce" <firstname.lastname@example.org>
> > >Reply-To: email@example.com
> > >To: Multiple recipients of list AROID-L <firstname.lastname@example.org>
> > >Subject: flowering 'juvenilies'
> > >Date: Thu, 15 Jun 2000 16:45:43 -0500 (CDT)
> > >
> > >Dear All
> > >
> > >The newly raised issue of juvenile monsteroids flowering is
> > >interesting because, while the production of flowers by a plant
> > >vegetatively in a juvenile phase does occur in the monsteroids,
> > >notably Monstera tuberculata, Rhaphidophora hayi, R. latevaginata,
> > >R. pachyphylla, R. parvifolia, R. okapensis and Scindapsus lucens,
> > >this 'M. dubia' thing is that the plants are flowering with very small
> > >leaves and BENEATH the leaves, whereas in all of those listed
> > >above while the juvenile growth morphology is retained into
> > >flowering in most instances the leaves of flowering individuals are
> > >considerably larger than those of youngsters and the
> > >inflorescences are carried clear of the leaves either at the tips of
> > >clinging shoots or on free shoots arising from the leaf axils. If the
> > >description of this 'dubia' plant is correct it would appear that
> > >inflorescences are arising directly from the leaf axils. Because
> > >aroids ALWAYS flower at the shoot apex it would mean that in this
> > >plant each inflorescence is carried at the tip of a very short shoot
> > >arising in the leaf axil (the same situation as in Pothos scandens) -
> > >a feature not yet recorded in the Monstereae.
> > >
> > >Pete
> > >
> > >----------------------------
> > >Peter Boyce
> > >Herbarium
> > >Royal Botanic Gardens, Kew
> > >Richmond, Surrey
> > >TW9 3AE
> > >Tel. (+44) (0)20 8 332 5207
> > >fax. (+44) (0)20 8 332 5278
> > >email: email@example.com (work)
> > > firstname.lastname@example.org (home)
> > >
> > >
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