[Taxacom] Biodiversity questions: Classifications

Thu Oct 3 12:31:45 CDT 2013

No, I didn't mean this. Yes, it can and should, if it originated at around the same time.

What I meant is that comparison of the current diversity of taxa of the same age = rank can only consider the surviving diversity.
You can replace 'current' with any geological time period. In most or even all cases we know about a too tiny fraction of extinctions to do an overall comparison of diversity of clades for their whole period of existence.

Frank

Dr. Frank-T. Krell
Curator of Entomology
Commissioner, International Commission on Zoological Nomenclature
Chair, ICZN ZooBank Committee
Department of Zoology
Denver Museum of Nature & Science
2001 Colorado Boulevard
Denver, CO 80205-5798 USA
Frank.Krell at dmns.org<mailto:Frank.Krell at dmns.org>
Phone: (+1) (303) 370-8244
Fax: (+1) (303) 331-6492
http://www.dmns.org/science/museum-scientists/frank-krell
lab page: http://www.dmns.org/krell-lab

The Denver Museum of Nature & Science aspires to create a community of critical thinkers who understand the lessons of the past and act as responsible stewards of the future.

From: Richard Jensen [mailto:rjensen at saintmarys.edu]
Sent: Thursday, October 03, 2013 11:20 AM
To: Frank T. Krell
Cc: Chris Thompson; Taxacom
Subject: Re: [Taxacom] Biodiversity questions: Classifications

Do you mean that an extinct speciose clade cannot have the same rank as an extant speciose clade?
Dick J

On Thu, Oct 3, 2013 at 12:46 PM, <Frank.Krell at dmns.org<mailto:Frank.Krell at dmns.org>> wrote:
It only tells us about the successful biodiversity, not the failing part.
If we do not ground our categories on age, then we cannot even discuss this aspect.
Frank

Dr. Frank-T. Krell
Curator of Entomology
Commissioner, International Commission on Zoological Nomenclature
Chair, ICZN ZooBank Committee
Department of Zoology
Denver Museum of Nature & Science
2001 Colorado Boulevard
Denver, CO 80205-5798 USA
Frank.Krell at dmns.org<mailto:Frank.Krell at dmns.org>
Phone: (+1) (303) 370-8244
Fax: (+1) (303) 331-6492
http://www.dmns.org/science/museum-scientists/frank-krell
lab page: http://www.dmns.org/krell-lab

The Denver Museum of Nature & Science aspires to create a community of critical thinkers who understand the lessons of the past and act as responsible stewards of the future.

-----Original Message-----
From: taxacom-bounces at mailman.nhm.ku.edu<mailto:taxacom-bounces at mailman.nhm.ku.edu> [mailto:taxacom-bounces at mailman.nhm.ku.edu<mailto:taxacom-bounces at mailman.nhm.ku.edu>] On Behalf Of Richard Jensen
Sent: Thursday, October 03, 2013 10:28 AM
To: Chris Thompson
Cc: TAXACOM
Subject: Re: [Taxacom] Biodiversity questions: Classifications

Could it be that the apparent discrepancy in biodiversity, as we perceive it, is that family Z has had just as many speciation events as family X, but has experienced extremely high rates of extinction?  If so, then knowing the age tells us nothing about biodiversity - the two clades, one with 999 surviving species, and one with 1 surviving species, could be the same age.

Dick J

On Thu, Oct 3, 2013 at 11:15 AM, Chris Thompson <xelaalex at cox.net<mailto:xelaalex at cox.net>> wrote:

> PAUL:
>
> The scientific question that we begin with was about biodiversity.
>
> And Hennig said to answer those kinds of questions, then groups based
> on time are the best.
>
> So, under the Hennig system, one could say that family X which now
> contains
> 999 species is more biodiversity, has more speciation, etc., than
> family Z which now contains only 1 species. BECAUSE the contents
> (species) of each family represents a clade that has evolved over the SAME time period.
>
> But as I indicated in my Diptera example, comparison of the number of
> species in Limoniidae versus Inbiomyiidae does not tell you anything
> about biodiversity, speciation, etc. because those groups are not
> equivalent, not comparable, etc.
>
> Oh, well ...
>
> Sincerely,
>
> Chris
>
> -----Original Message-----
> From: muscapaul
> Sent: Thursday, October 03, 2013 10:27 AM
> To: TAXACOM
> Subject: Re: [Taxacom] Biodiversity questions: Classifications
>
> Just out of interest: If actual age would (should?) be playing a role,
> where do we then account for differences between taxa with highly
> divergent generation time, like drosophilids with perhaps more than 10
> generations per year under favourable conditions and panthophthalmids
> which probably take multiple years to develop? And then I am just
> considering taxa within the same order where one might give rise to
> new taxa on a much shorter absolute time scale than the other.
>
> Paul
>
> On 3 October 2013 12:59, Chris Thompson <xelaalex at cox.net<mailto:xelaalex at cox.net>> wrote:
>
> > So, for example, in Diptera, we now recognize a family which is a
> > clade
> of
> > some 10 thousand species and of some 200 million years old
> > (Limoniidae) and another family of less than a dozen species and
> > probably less than 5 million years old (Inbiomyiidae).
>
> ...
> >
> > So, if one wants to derived scientific hypotheses from classifications,
> > one
> > must go back to clades and their age.
> >
> > Sincerely,
> >
> > Chris
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--
Richard Jensen, Professor
Department of Biology
Saint Mary's College
Notre Dame, IN 46556
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(1) by visiting http://taxacom.markmail.org

(2) a Google search specified as:  site:mailman.nhm.ku.edu/pipermail/taxacom<http://mailman.nhm.ku.edu/pipermail/taxacom>  your search terms here

Celebrating 26 years of Taxacom in 2013.

--
Richard Jensen, Professor
Department of Biology
Saint Mary's College
Notre Dame, IN 46556