Exist sub-species?????

[Gurcharan Singh]

-----Original Message-----
From: Gerardo Tapia <grodrig at XOLO.CONABIO.GOB.MX>
To: <TAXACOM at USOBI.ORG>
Date: 09 November, 1999 12:43 AM
Subject: Exist sub-species?????


>Taxacomers
>
>What is your opinion to this question:
>
>-Do sub-species exist?
>- And if they do how are they defined?
>
>P. S. Can you cite the literature on this subject.
>
>Thanks
>Gerardo Tapia
>

Speciation is not just one big leap. It is a gradual evolutionary
process.Populations with distinct characteristics are encountered and we
have to give them names to distinguish. A population of a species may show
adaptations (adaptive radiations) to a particular area which intitially are
not genetically fixed (Ecads or Ecophenes). Once these adaptations are
genetically fixed they are ecotypes. A step further when differences are
more pronounced we call them subspecies and varieties. Although all may not
agree on the status of subspecies and varieties, it was best explained by Du
Toit (1930) who considered subspecies as "population of various biotypes
representing regional facies of a species. Variety he defined as "population
of various biotypes representing local facies of a species". Thus variants
of a species in different geographical areas are subspecies whereas within
the same geographical area are varieties. They are one step short of
species. once reproductive isolation develops the populations   qualify to
be called as species.

Gurcharan Singh

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Dr. Gurcharan Singh                      Res:
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