Extinction vs accuracy

[Kenelm Philip]

Out of curiosity, I looked up 'extinction' and 'extirpation' in
'A Dictionary of Ecology, Evolution and Systematics' by Lincoln, Boxshall,
and Clark, 2nd edition, 1998, Cambridge U.P.--a most useful reference.
 
"extinction  1: The process of elimination, as of less fit genotypes. 2:
The disappearance of a species or taxon from a given habitat or biota, not
precluding later recolonization from elsewhere.
 
extirpation  1: Surgical removal of a part; destroying totally; pulling
up by the roots. 2: Extermination of the population of a given species
from an area."
 
I see little difference between 'extinction 2' and 'extirpation 2'.
 
        More to the point, however, might be the following entries:
 
"extinct (Ex)  In the IUCN Categories q.v. of threatened species. those
taxa that have not been definitely located in the wild during the past
50 years.
 
extinct (EX)  In the proposed IUCN Criteria q.v. for threatened species,
a taxon is categorized as extinct when there is no reasonable doubt that
the last individual of that taxon has died.
 
extinct in the wild (EW)  In the proposed IUCN Criteria q.v. for threatened
species, a taxon is categorized as extinct in the wild when it is known to
survive only in cultivation, in captivity, or as naturalized populations
outside the former range."
 
                                                        Ken Philip
fnkwp at uaf.edu
 
 
 
 
 
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