[Taxacom] Pop article on taxonomy's decline

Tony.Rees at csiro.au Tony.Rees at csiro.au
Sun Jan 30 19:07:46 CST 2011


Stephen Thorpe wrote:

> yes, but I thought the context of this thread (as the subject heading suggests) was about a possible
> present decline in taxonomy? If so, then estimating the current rate of taxonomic activity from legacy
> data doesn't really help! The question is has it slowed down in recent years?

Well, I’m first trying to establish a baseline here, from which one can potentially see whether more recent quoted rates of taxon descriptions look plausible or not.

I cannot provide independent numbers on new species descriptions, but can (to a degree) for new genera for some groups at this time (more to come). For example in vascular plants, excluding fossil ones, here are some possible numbers of interest:

Year  .. new genera described (excluding orchid and other hybrids, which otherwise distort the figures)

1991      65
1992      60
1993      69
1994      65
1995      51
1996      49
1997      59
1998      72
1999      64
2000      69
2001      53
2002      32
2003      59
2004      55
2005      39
2006      67
2007      46
2008      27 *
2009      16 *
2010      14 *

These figures are estimates based on incomplete analysis because I have not finished working through all the available data, but will not be far off, except for the “recent data lag” which most likely influences the figures from 2008-2010 (marked *) to some extent, or maybe even for a year or two preceding as well. (I could do the same for some other key groups given a bit more time).

So, ignoring the 2008-2010 values maybe, the mean value through the ‘90s was a bit higher (61.5 new extant vascular plant genera/yr) than for the ‘00s (52.5)  - let the interpretations commence…

Regards - Tony


________________________________
From: "Tony.Rees at csiro.au" <Tony.Rees at csiro.au>
To: stephen_thorpe at yahoo.co.nz; TPape at snm.ku.dk; taxacom at mailman.nhm.ku.edu
Sent: Sun, 30 January, 2011 1:26:26 PM
Subject: RE: [Taxacom] Pop article on taxonomy's decline

Dear Stephen, all,

Well I have not tried to validate that figure directly as yet, but it's a hypothesis open to confirmation or falsifying on a group-by-group basis, as and when accurate figures are available; and of course one would expect some variation between groups as well. Overall it is really a legacy figure based on my (again provisional) guesstimate of perhaps 250,000 valid genera (for all groups) and around 2.2 million valid species (1.9m extant, 0.3m fossil), and presuming that at least as a first approximation such ratios continue with the desciption of new taxa - again open to disproof of course, but a basis for some at least order-of-magnitude estimates for various tasks invlving names compilations and so on. Of course if someone has a more accurate figure for valid genera, extant and fossil, we can simply plug that in instead (maybe as low as 200,000, I'm not sure, but probably in that order anyway).

Interestingly in vascular plants, for which the Plant List has recently published a species-level synopsis, the following stats are given:


"The Plant List contains 620 plant families and 16,167 plant genera.

The status<http://www.theplantlist.org/about/#status> of the 1,040,426 species names, are as follows:


        Status  Total

◕      Accepted<http://www.theplantlist.org/about/#accepted>  298,900 28.7%
◕      Synonym<http://www.theplantlist.org/about/#synonym>    477,601 45.9%
◕      Unresolved<http://www.theplantlist.org/about/#unresolved>      263,925 25.4%
"

Note that to do the analysis we want, we need to know what proportion of the genera are synonyms, and guesstimate what proportion of the "unresolved" species names will turn out to be good species. Let's try and put some guesstimates in there and see what pops out: presume that 20% of the genus names are synonyms (I have not checked, but plan to do so at some point) and 20% of the unresolved names will turn out to be good species - gives 325,000 valid species in 12,900 valid genera = around 25 valid species/genus on average, as opposed to the figure of 8 I have presumed as a mean across all groups. So, either the vascular plants are much more speciose per genus than other organisms, or my average of 8 is a gross underestimate. I would suspect the former, but happy to revise the latter upwards if it seems justified - it would be interesting to see some figures for other groups, particularly major insect groups and crustaceans. Then to see real trends worthy of extrapolation, one should do the analysis on a year by year basis instead of the overall totals - certainly possible in some groups for which the valid species and genera are well known (although one would need to distinguish real new species from new combinations, and somehow decide exactly what to count in the genus context too).

Hoping the above is of maybe some interest,

Regards - Tony

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