[Taxacom] Biodiversity questions: Classifications

Chris Thompson xelaalex at cox.net
Thu Oct 3 10:15:30 CDT 2013


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 ...



-----Original Message----- 
From: muscapaul
Sent: Thursday, October 03, 2013 10:27 AM
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.


On 3 October 2013 12:59, Chris Thompson <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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