Home | Community | Message Board

Mycohaus
This site includes paid links. Please support our sponsors.


Welcome to the Shroomery Message Board! You are experiencing a small sample of what the site has to offer. Please login or register to post messages and view our exclusive members-only content. You'll gain access to additional forums, file attachments, board customizations, encrypted private messages, and much more!

Shop: Mushroom-Hut Substrate Bags   PhytoExtractum Buy Bali Kratom Powder   North Spore Bulk Substrate   Unfolding Nature Unfolding Nature: Being in the Implicate Order   Left Coast Kratom Buy Kratom Extract

Jump to first unread post Pages: 1
Some of these posts are very old and might contain outdated information. You may wish to search for newer posts instead.
Offlinepluteus
level-9 deviant

Registered: 08/12/03
Posts: 170
Loc: London area, UK
Last seen: 17 years, 2 months
Re: sympatric specification in the genus Psilocybe [Re: Zen Peddler]
    #2076680 - 11/06/03 10:20 AM (20 years, 2 months ago)

By 'specification', are you talking about speciation?

Sympatric speciation is considered to be the major mechanism of mushroom diversification, because the opportunities for these highly dispersable organisms to become geographically isolated are relatively rare.

The questions you're asking apply to all mushrooms, not just psilocybes.

Speciation can then be understood in terms of general models applied to other organisms. Trends of resource partitioning, divergent selection, etc., lead to genetic isolation of sub-populations. The exact way in which this occurs is still hotly debated

Mushrooms also have some unique genetic properties which may assist speciation events. Because mating type loci can become self-compatible as a result of only a few single mutations, mushroom lineages can switch breeding systems abruptly, leading to rapid sympatric isolation.

MJshroomer's suggestion that the introduction of woodchip mulch and foreign trees into new areas has caused mushroom speciation is flawed. I say this because based on comparative DNA evidence, these psilocybe species diverged from each other at least tens of thousands of years before humans arrived in North America.

I do agree, however, that these 'artificial' substrates will have interesting effects on population dynamics, potentially leading to speciation events in the future.

Bearing all this in mind, I can say a few things about the possibility of P. eucalypta and P. subaeruginosa being conspecific. You say that these mushrooms are found in the same conditions and on the same substrates, but this does not necessarily mean they are using exactly the same resources. For instance they might specialize in degrading slightly different types of lignin even within the same piece of dead wood (I have no idea if this is true, it's just an example). This would be sufficient for their co-existence as distinct species.

On the other hand, they might be phenotypic extremes within a common population, that is beginning to diverge.

In this and similar cases, you won't find an conclusive answer by examining subtle differences in morphology. Molecular and mating work must be done. I'm afraid I don't know enough about the morphological differences of these two groups to predict what the molecular work would find.

I don't really see what all this is doing on the hunting forum, but I guess there isn't a forum for evolutionary / molecular / ecological mycology...


Extras: Unfilter Print Post Top
Offlinepluteus
level-9 deviant

Registered: 08/12/03
Posts: 170
Loc: London area, UK
Last seen: 17 years, 2 months
Re: sympatric specification in the genus Psilocybe [Re: ]
    #2077135 - 11/06/03 01:19 PM (20 years, 2 months ago)

Mr. Mushrooms -
"Certainly we have seen enough evidences of speciation on various islands, i.e. Galapagos, Hawaii, etc to warrant the acceptance of the principles to which you are referring."

These are textbook examples of allopatric, not sympatric speciation.  The theoretical principles are very different and much more contested in sympatric scenarios.

"However, notice that there are virtually no evidences of mushroom speciation that produce basidiocarps on these islands."

Obviously.  These islands lie relatively close together and therefore mushroom spores could be easily dispersed between them, remaining in a common gene pool.  Unlike small birds, reptiles, etc., which are clearly genetically isolated by being on different islands, mushrooms are not.  This is why bluemeanie raised the issue of SYMPATRIC speciation mechanisms, which do not rely on geographic isolation.

"We have seen the evidence of widely varying morphological and taxonomic features both macroscopically and microscopically. These lifeforms grade into each other so much that it becomes difficult, if not impossible, to draw a speciation line."

This is an over-generalization.  The majority of named species are morphologically and genetically distinct.  Of course there are many problematic exceptions, but these can be resolved by examining population genetics.  In these cases we have to remember that 'species' is a human label that often fails to describe the complexity of reality, and be content with knowing to what extent populations exchange genetic material.  Whether we then decide to call such populations 'species' or not is not really important, considering we have this level of understanding.

"As an example let me share a few quotes from talkorigins to illustrate the confusion"

You quote from a history detailing refinements of biological species concepts.  This is not really relevant to the issue of sympatric speciation, because it is merely a debate over how to most accurately describe the basic units of diversity.  No one would argue against the existence of diversity nor against the existence of processes of diversification.  Such processes (i.e. sympatric speciation) can be studied without the need for an absolutely standard definition of biological species (because, of course, in reality there are no 'standard units').


"I don't think we know enough yet about how evolution works to be able to answer the question with the amount of certitude that would make me comfortable."

If you are not comfortable, I wonder if you are familiar with the recent literature on the population genetics of recently diverged and diverging groups of mushrooms?  We do know an increasing amount about how genetic isolation evolves between both sympatric and allopatric populations of mushrooms, and the selective forces driving divergence.  I am talking about detailed  molecular characterizations and evolutionary reconstructions that build a very convincing picture of reinforcement mechanisms.

If you are familiar with this literature, and still don't feel comfortable, I don't blame you  :smile:
   


Extras: Unfilter Print Post Top
Offlinepluteus
level-9 deviant

Registered: 08/12/03
Posts: 170
Loc: London area, UK
Last seen: 17 years, 2 months
Re: sympatric specification in the genus Psilocybe [Re: Zen Peddler]
    #2119601 - 11/18/03 11:42 AM (20 years, 2 months ago)

Mr. Mushrooms said: "Hawaii, for example, is completely isolated from the continents and probably has had plenty of time for new mushroom species to occur. And yet they haven't. Plenty of other lifeforms have evolved there and Hawaii is a textbook case for allopatric speciation or the founder effect. How do you answer that?"

When you first mentioned the islands of Galapagos and Hawaii as being textbook cases for speciation, I assumed you were referring to the famous studies of how allopatric speciation has occurred within, and entirely within these archipelagos (disregarding the founding individuals). For example, studies of the adaptive radiation of Galapagos finches and the diversification of Hawaiian fruit flies have shown how geographically isolated populations inhabiting neighbouring islands have evolved into different species, under different selection pressures.  I made the point that, in contrast to finches and fruit flies, mushroom populations living on neighbouring islands would not be significantly isolated.

I now understand that you were taking a broader view of these scenarios, and asking why islands such as these don?t have an endemic mycoflora, with reference to neighbouring continents.

My answer is that to some extent they do.  However, I would argue that perhaps even in Hawaii, the most isolated group of islands, the extremely high dispersibility of mushroom spores is still the major factor affecting species distribution, acting to homogenize mycoflora on a hemisphere and even global scale.  You say that "plenty of other lifeforms have evolved [in Hawaii]", but fail to consider that all of the examples you're thinking of are nowhere near as dispersable as mushrooms.

Having said this, I will backtrack a bit and concede that local speciation events are important - but if you look to isolated islands for evidence of this you will be disappointed.  It is very likely that Hawaii, before European settlement, supported a more diverse endemic mycoflora, a small fraction of which persists today, having been outcompeted by introduced species. There is much convincing evidence to support this.  Genetic analysis of some common Hawaiian mushroom species have shown that they are almost certainly recent, alien arrivals from overseas. The legislation that Mjshroomer cites prohibiting species importation is a response to what has already been a catastrophic reduction in the diversity of Hawaii?s endemics due to invasive species.  Many ecology textbooks present Hawaii as a prime example of the susceptibility of long-isolated island ecosystems to invasion (I am talking about a 80-90% reduction in some major groups).  So, the impoverished mycoflora of today?s Hawaii gives little clue to the diversity that may have existed several hundred years ago.  The same holds true for other islands - in fact the fungal community may be the first to be replaced during invasion events.


Mr. Mushrooms also said:  "My point was, and is, that the species line blurs. You should ask Lizard King about the widely varying macroscopic morphological differences in Psilocybe weilii to the point that a person would think they are picking a half a dozen different mushrooms. This is why we normally rely on the microscopic differences to differentiate between species. This is bluemeanie's whole point. He has been working on the various species from Australia for some time now."

Apart from making provisional identifications, I am really not interested in morphological species concepts for mushrooms, be they macro- or microscopic.  They?re inconsistent.  The relatively simple cellular organization of mushrooms serves poorly to record their evolutionary history.  As I have explained, on the *genetic* level, mushroom species or lineages are readily differentiable and distinguishable, given sufficiently detailed analysis.  (I do not mean that ?species? are always readily understandable according to a strict biological species concept, but instead that genetic analyses, combined with judiciously selected mating tests, provide a level of resolution that is much more useful than any BSC-constrained definition.)  Field collectors or cultivators of psilocybes may not find genetic definitions of mushroom species very useful, but there?s no argument that species boundaries are usually and persistently blurred beyond our comprehension, just because microscopes and eyeballs cannot detect properties of genetic divergence.

Bluemeanie said: "any one have the means to conduct a compatibility / isozyme test/comparison? I had a guy in Canada doing it, but he hasnt replied for a while."

I can do better than isozymes (DNA sequence analysis + selective crossing tests), send me a message if you?re interested.  Given the right material I could resolve relationships between your australian species without much difficulty - I'd be happy to take this on.

Teonan ? I agree completely with your critique of MJShroomer?s post.  To me, MJShroomer seems to be an excellent morphological taxonomist.

Finally, to return to the original questions about speciation mechanisms, I?ve compiled a background reading list:

Ko, S.K., Young, Lim, W.K., Yang, H.K., and H.S. Jung (2001) Phylogeographic divergences of nuclear ITS sequences in Coprinus species sensu lato, MYCOLOGICAL RESEARCH 105(12) pp.1519-1526
[This Korean study, published in a British journal, gives an example of how the original locality of a speciation event may be determined for a globally-distributed species.  It also quantifies ITS divergence and phylogeography within four coprinoid species, and shows how some types of DNA data give evidence for the existence of cryptic species]

Vilgalys, R. and B.L. Sun (1994) Ancient and recent patterns of geographic speciation in the oyster mushroom Pleurotus revealed by phylogenetic analysis of ribosomal DNA sequences, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES USA 91 pp4599-4603
[relationships between genetic divergence, reproductive isolation and biogeography are examined using sequence data in this study by America?s most prolific mushroom sequencer, Rytas Vilgalys]

Hibbett, D.S., Hansen, K. and M.J. Donoghue (1998) Phylogeny and biogeography of Lentinula inferred from an expanded rDNA dataset, MYCOLOGICAL RESEARCH 102 pp.1041-1049

Hibbett, D.S., Fukumasa-Nakai, Y., Tsuneda, A. & M.J. Donoghue (1995) Phylogenetic diversity in shiitake inferred from nuclear ribosomal species, MYCOLOGIA 87 pp618-638
[studies by Hibbett, a leading American evolutionary mycologist, which continue the molecular approach to studying mushroom speciation, with an emphasis on between-species relationships]

[The past decade has seen a proliferation of studies like this, which focus on different mushroom groups at different levels of resolution. Some ponder evolutionary questions relating to speciation mechanisms, but most are concerned primarily with relationships ? i.e. pure systematics.  I will not bother to list these here but feel free to msg me if these are of interest]


Chase, T.E. and R.C. Ulrich (1990) MYCOLOGIA 82 pp.73-81 and 67-72
[studies of the mushroom species Heterobasidion annosum which suggest that reproductive isolation of mushroom populations may evolve rapidly through the action of just a  few intersterility loci, which override mating compatibility]

Ramsdale, Mark, and Alan Rayner (1994) Distribution patterns in number of nuclei in conidia from heterokaryons of Heterobasidion annosum and their interpretation in terms of genomic conflict, NEW PHYTOLOGIST 128 pp123-134

Ramsdale, Mark, and Alan Rayner (1996) Imbalanced nuclear ratios, post-germination mortality and phenotype-genotype relationships in allopatrically-derived heeterokaryons of Heterobasidion annosum, NEW PHYTOLOGIST 133 pp303-319
[these two papers co-authored by the highly eccentric Rayner begin to present an original and thought-provoking way of understanding speciation (this is my interpretation rather than something explicitly stated) in terms of the dynamics of conflict and co-operation between potentially co-existing populations of nuclei]

hope these are of interest, if anyone?s managed to read this far    :confused:

(I think this will be my last post on this subject, as it?s an inappropriate forum - perhaps an email group or some other forum would be more suited ? contact me if you have any ideas)  :smile2:   


Extras: Unfilter Print Post Top
Jump to top Pages: 1

Shop: Mushroom-Hut Substrate Bags   PhytoExtractum Buy Bali Kratom Powder   North Spore Bulk Substrate   Unfolding Nature Unfolding Nature: Being in the Implicate Order   Left Coast Kratom Buy Kratom Extract


Similar ThreadsPosterViewsRepliesLast post
* Mistaking Poison Fungi for Psilocybes oO_wombat_Oo 2,367 6 03/21/02 12:33 AM
by Jammer
* How to identify Psilocybe Species and Panaeolus. (Illus.)
( 1 2 3 all )
mjshroomer 64,660 52 04/15/09 12:34 PM
by Alan Rockefeller
* Psilocybe azurescens season and locations in oregon???
( 1 2 all )
AIRDOG 39,556 36 11/03/05 06:23 AM
by ClammyJoe
* Copelandia cyanescens: A Pictorial for Shroom Hunters mjshroomer 3,951 7 03/16/06 08:55 AM
by mjshroomer
* Psilocybe Features? Bilge 2,423 6 04/05/03 06:28 PM
by cardboard
* Copelandia Cyanescens (Blue Meanies) in NZ
( 1 2 3 all )
MagicalKnife 25,821 43 07/19/10 12:43 AM
by inski
* Panaeolus and Copelandias - questions. oO_wombat_Oo 2,900 4 03/19/02 03:22 AM
by zeronio
* Copelandia cyanescens shroomsoldier 3,544 11 03/05/04 01:41 AM
by kenjaman

Extra information
You cannot start new topics / You cannot reply to topics
HTML is disabled / BBCode is enabled
Moderator: ToxicMan, inski, Alan Rockefeller, Duggstar, TimmiT, Anglerfish, Tmethyl, Lucis, Doc9151, Land Trout
5,465 topic views. 2 members, 16 guests and 5 web crawlers are browsing this forum.
[ Show Images Only | Sort by Score | Print Topic ]
Search this thread:

Copyright 1997-2024 Mind Media. Some rights reserved.

Generated in 0.024 seconds spending 0.009 seconds on 17 queries.